SECTION 6E2 - ENGINE DRIVEABILITY AND EMISSIONS

Specification

Tightening Specifications

Diagrams and Schematics

PCM Wiring Diagram (1 of 8)

PCM Wiring Diagram (2 of 8)

PCM Wiring Diagram (3 of 8)

PCM Wiring Diagram (4 of 8)

PCM Wiring Diagram (5 of 8)

PCM Wiring Diagram (6 of 8)

PCM Wiring Diagram (7 of 8)

PCM Wiring Diagram (8 of 8)

PCM Pinouts

PCM Pinout Table, 32-Way Red Connector

– Row “A”

PCM Pinout Table, 32-Way Red Connector

– Row “B”

PCM Pinout Table, 32-Way White Connector

– Row “C”

PCM Pinout Table, 32-Way White Connector

– Row “D”

PCM Pinout Table, 32-Way Blue Connector

– Row “E”

PCM Pinout Table, 32-Way Blue Connector

– Row “F”

Component Locators

Engine Component Locator Table

Undercarriage Component Locator

Undercarriage Component Locator Table

Sensors and Miscellaneous Component

Locators

Fuse and Relay Panel (Underhood Electrical

Center)

Diagnosis

Strategy-Based Diagnostics

DTC Stored

No DTC

No Matching Symptom

Intermittents

No Trouble Found

Verifying Vehicle Repair

General Service Information

Non-OEM Parts

Environment

Emissions Control Information Label

Maitenance Schedule

Visual/Physical Engine Compartment

Inspection

Basic Knowledge of Tools Required

Seral Data Communications

Class II Serial Data Communications

On-Board Diagnostic (OBD)

On-Board Diagnostic Tests

Comprehensive Component Monitor

Diagnostic Operation

Common OBD Terms

The Diagnostic Executive

DTC Types

Verifying Vehicle Repair

Reading Diagnostic Trouble Codes Using

the TECH 2 Scan Tool

Tech 2

Tech 2 Features

Getting Started

Operating Procedure (For Example)

DTC Modes

DTC Information Mode

Miscellaneous Test

Lamps Test

Relays Test

EVAP Test

Idle Air Control System Test

Fuel System Test

EGR Control Test

Variable Intake Manifold Solenoid Test

Injector Balance Test

Plotting Snapshot Graph

Plotting Graph Flow Chart (Plotting graph

after obtaining vehicle information)

Flow Chart for Snapshot Replay

(Plotting Graph)

Primary System-Based Diagnostics

Fuel Control Heated Oxygen Sensors

HO2S Heater

On-Board Diagnostic (OBD) System Check

Circuit Description

Diagnostic Aids

A/C Clutch Control Circuit Diagnosis

Circuit Description

Diagnostic Aids

A/C Clutch Diagnosis

Electronic Ignition System Diagnosis

Techline

Visual Check of The Evaporative Emission

Canister

Fuel Metering System Check

Idle Air Control (IAC) Valve

Knock Sensor Diagnosis

Powertrain Control Module (PCM) Diagnosis

Multiple PCM Information Sensor DTCS Set

Exhaust Gas Recirculation (EGR) Diagnosis

Engine Tech 2 Data Definitions and Ranges

Typical Scan Data Values

No Malfunction Indicator Lamp (MIL)

Malfunction Indicator Lamp (MIL) “ON”

Steady

Engine Cranks But Will Not Run

Fuel System Diagnosis

Idle Air Control (IAC) System Check

Knock Sensor (KS) System Check (Engine

Knock, Poor Performance, or Poor

Economy)

Exhaust Gas Recirculation (EGR) System

Check

Manifold Absolute Pressure (MAP) Output

Check

Evaporative (EVAP) Emissions Canister Purge

Valve Check

PCM Diagnostic Trouble Codes

Diagnostic Trouble Code (DTC) P0101 MAF

System Performance

Diagnostic Trouble Code (DTC) P0102 MAF

Sensor Circuit Low Frequency

Diagnostic Trouble Code (DTC) P0103 MAF

Sensor Circuit High Frequency

Diagnostic Trouble Code (DTC) P0107 MAP

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0108 MAP

Sensor Circuit Hight Voltage

Diagnostic Trouble Code (DTC) P0112 IAT

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0113 IAT

Sensor Circuit High Voltage

Diagnostic Trouble Code (DTC) P0117 ECT

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0118 ECT

Sensor Circuit High Voltage

Diagnostic Trouble Code (DTC) P0121 TP

System Performance

Diagnostic Trouble Code (DTC) P0122 TP

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0123 TP

Sensor Circuit High Voltage

Diagnostic Trouble Code (DTC) P0131 HO2S

Circuit Low Voltage Bank 1 Sensor 1

Diagnostic Trouble Code (DTC) P0132 HO2S

Circuit High Voltage Bank 1 Sensor 1

Diagnostic Trouble Code (DTC) P0134 HO2S

Circuit Insufficient Activity Bank 1 Sensor 1

Diagnostic Trouble Code (DTC) P0151 HO2S

Circuit Low Voltage Bank 2 Sensor 1

Diagnostic Trouble Code (DTC) P0152 HO2S

Circuit High Voltage Bank 2 Sensor 1

Diagnostic Trouble Code (DTC) P0154 HO2S

Circuit Insufficient Activity Bank 2 Sensor 1

Diagnostic Trouble Code (DTC) P0171 Fuel

Trim System Too Lean Bank 1

Diagnostic Trouble Code (DTC) P0172 Fuel

Trim System Rich Bank 1

Diagnostic Trouble Code (DTC) P0174 Fuel

Trim System Lean Bank 2

Diagnostic Trouble Code (DTC) P0175 Fuel

Trim System Rich Bank 2

Diagnostic Trouble Code (DTC) P0201 Injector

1 Control Circuit

Diagnostic Trouble Code (DTC) P0202 Injector

2 Control Circuit

Diagnostic Trouble Code (DTC) P0203 Injector

3 Control Circuit

Diagnostic Trouble Code (DTC) P0204 Injector

4 Control Circuit

Diagnostic Trouble Code (DTC) P0205 Injector

5 Control Circuit

Diagnostic Trouble Code (DTC) P0206 Injector

6 Control Circuit

Diagnostic Trouble Code (DTC) P0325 KS

Module Circuit

Diagnostic Trouble Code (DTC) P0327 KS

Sensor Circuit

Diagnostic Trouble Code (DTC) P0336 58X

Reference Signal Circuit

Diagnostic Trouble Code (DTC) P0337 CKP

Sensor Circuit Low Frequency

Diagnostic Trouble Code (DTC) P0341 CMP

Sensor Circuit Performamce

Diagnostic Trouble Code (DTC) P0342 CMP

Sensor Circuit Low

Diagnostic Trouble Code (DTC) P0351 Ignition

1 Control Circuit

Diagnostic Trouble Code (DTC) P0352 Ignition

2 Control Circuit

Diagnostic Trouble Code (DTC) P0353 Ignition

3 Control Circuit

Diagnostic Trouble Code (DTC) P0354 Ignition

4 Control Circuit

Diagnostic Trouble Code (DTC) P0355 Ignition

5 Control Circuit

Diagnostic Trouble Code (DTC) P0356 Ignition

6 Control Circuit

Diagnostic Trouble Code (DTC) P0404 EGR

Open Stuck

Diagnostic Trouble Code (DTC) P0405 EGR

Low Voltage

Diagnostic Trouble Code (DTC) P0406 EGR

High Voltage

Diagnostic Trouble Code (DTC) P0502 VSS

Circuit Low Input

Diagnositc Troule Code (DTC) P0562 System

Voltage Low

Diagnostic Trouble Code (DTC) P0563 System

Voltage High

Diagnostic Trouble Code (DTC) P0601 PCM

Memory

Diagnostic Trouble Code (DTC) P1171 Fuel

System Lean Dueing Acceleration

Diagnostic Trouble Code (DTC) P1380 ABS

Rough Road ABS System Fault

Diagnostic Trouble Code (DTC) P1381 ABS

Rough Road Class 2 Serial Link Error

Diagnostic Trouble Code (DTC) P1404 EGR

Stuck Closed

Diagnostic Trouble Code (DTC) P1508 IAC

System Low RPM

Diagnostic Trouble Code (DTC) P1509 IAC

System High RPM

Diagnostic Trouble Code (DTC) P1625 PCM

Unexpected Reset

Diagnostic Trouble Code (DTC) P1640 Output

Driver Module (ODM) “A” Fault

Symptom Diagnosis

Default Matrix Table

On-Vehicle Service Camshaft Position (CMP)

Sensor

Crankshaft Position (CKP)

Sensor

Engine Coolant Temperature (ECT) Sensor

Heated Oxygen Sensor (HO2S)

Intake Air Temperature (IAT) Sensor

Knock Sensor (KS)

Mass Air Flow (MAF) Sensor

Manifold Absolute Pressure (MAP) Sensor

Malfunction Indicator Lamp (MIL)

Powertrain Control Module (PCM)

EEPROM

Throttle Position (TP) Sensor

Vehicle Speed Sensor (VSS)

Air Cleaner/Air Filter

Idle Air Control (IAC) Valve

Common Chamber

Accelerator Cable Assembly

Accelerator Pedal Replacement

Fuel Fillter Cap

Fuel Filter

Fuel Gauge Unit

Fuel Injectors

Fuel Pressure Regulator

Fuel Metering System

Fuel Pump Assembly

Fuel Pump Relay

Fuel Rail Assembly

Fuel Tank

Throttle Body (TB)

Electronic Ignition System

Catalytic Converter

Air Conditioning Relay

EVAP Canister Hoses

EVAP Canister

EVAP Canister Purge Solenoid

Fuel Tank Vent Valve

Linear Exhaust Gas

Recirculation (EGR) Valve

Positive Crankcase Ventilation (PCV) Valve

Wiring and Connectors

PCM Connectors and Terminals

Wire Harness Repair: Twisted Shielded Cable

Twisted Leads

Weather-Pack Connector

Com-Pack III

Metri-Pack

General Description (PCM and Sensors)

58X Reference PCM Input

A/C Request Signal

Crankshaft Position (CKP) Sensor

Camshaft Position (CMP) Sensor and

Signal

Engine Coolant Temperature (ECT) Sensor

Electrically Erasable Programmable Read

Only Memory (EEPROM)

Fuel Control Heated Oxygen Sensors

Intake Air Temperature (IAT) Sensor

Knock Sensor

Linear Exhaust Gas Recirculation (EGR)

Control

Mass Air Flow (MAF) Sensor

Manifold Absolute Pressure (MAP) Sensor

Powertrain Control Module (PCM)

PCM Function

PCM Components

PCM Voltage Description

PCM Input/Outputs

PCM Service Precautions

Throttle Position (TP) Sensor

Transmission Fluid Temperature (TFT)

Sensor

Transmission Range Switch

Vehicle Speed Sensor (VSS)

Use of Circuit Testing Tools

Aftermarket Electrical and Vacuum

Equipment

Electrostatic Discharge Damage

Upshift Lamp

General Description (Air Induction)

Air Induction System

General Description (Fuel Metering)

Acceleration Mode

Accelerator Controls

Battery Voltage Correction Mode

CMP Signal

Clear Flood Mode

Deceleration Mode

Engine Speed/Vehicle Speed/Fuel

Disable Mode

Fuel Cutoff Mode

Fuel Injector

Fuel Metering System Components

Fuel Metering System Purpose

Fuel Pressure Regulator

Fuel Pump Electrical Circuit

Fuel Rail

Idle Air Control (IAC) Valve

Run Mode

Starting Mode

Throttle Body Unit

General Description (Electronic Ignition

System)

Camshaft Position (CMP) Sensor

Crankshaft Position (CKP) Sensor

Electronic Ignition

Ignition Coils

Ignition Control

Ignition Control PCM Output

Knock Sensor (KS) PCM Input

Powertrain Control Module (PCM)

Spark Plug

A/C Clutch Diagnosis

A/C Clutch Circuit Operation

A/C Clutch Circuit Purpose

A/C Request Signal

General Description (Evaporative (EVAP)

Emission System)

EVAP Emission Control System Purpose

EVAP Emission Control System Operation

General Description (Exhaust Gas

Recirculation (EGR) System)

EGR Purpose

Linear EGR Valve

Linear EGR Control

Linear EGR Valve Operation and Results

of Incorrect Operation

EGR Pintle Position Sensor

General Description (Positive Crankcase

Ventilation (PCV) System)

Crankcase Ventilation System Purpose

Crankcase Ventilation System Operation

Special Tools

Specification

Tightening Specifications

Application N·m kg·m Lb Ft. Lb In.

Camshaft Position Sensor Retaining Screw 9 0.9 — 78

Crankshaft Position Sensor Mounting Bolt 9 0.9 — 78

EGR Bolt 14 1.4 — 122

EGR Nut 14 1.4 — 122

Engine Coolant Temperature Sensor 30 3.1 22 —

Fuel Pressure Regulator Attaching Screw 6.5 0.65 — 56

Fuel Rail Bolts 25 2.5 18 —

Fuel Tank Undercover Retaining Bolts 36 3.7 27 —

Heated Oxygen Sensor 42 4.3 32 —

Lower Intake Manifold to Engine Block Bolts 25 2.5 18 —

Fuel Drain Plug 29 3.0 22 —

Lower Intake Manifold to Engine Block Nuts 25 2.5 18 —

Spark Plugs 18 1.8 13 —

Throttle Body Mounting Bolts 13 1.3 —113

Upper Intake Manifold to Lower Intake Manifold Bolts 25 2.5 18 —

VSS Retaining Bolt 13 1.3 —113

Diagrams and Schematics

PCM Wiring Diagram (1 of 8)

D06RX128

PCM Wiring Diagram (2 of 8)

D06RX003

PCM Wiring Diagram (3 of 8)

D06RX146

PCM Wiring Diagram (4 of 8)

D06RX129

PCM Wiring Diagram (5 of 8)

D06RX130

PCM Wiring Diagram (6 of 8)

D06RX131

PCM Wiring Diagram (7 of 8)

D06RX132

PCM Wiring Diagram (8 of 8)

D06RX133

PCM Pinouts

PCM Pinout Table, 32-Way Red Connector – Row “A”

TS23344

PIN PIN Function Wire Color IGN ON ENG RUN Refer To

A1 5 Volt Reference “A” RED 5.0 V 5.0 V Appropriate Sensor

A2 Knock Sensor YEL 0.0 V 0.0 V General Description and

Operation, Knock Sensor

A3 Not Used

A4 Battery Feed (ECM Fuse) RED/WHT B+ B+ Chassis Electrical

A5 Idle Air Control (IAC) “A”

High BLU B+/0.8 V B+/0.8 V General Description and

Operation, IAC

A6 IAC “A” Low BLU/WHT B+/0.8 V B+/0.8 V General Description and

Operation, IAC

A7 IAC “B” Low BLU/BLK B+/0.8 V B+/0.8 V General Description and

Operation, IAC

A8 IAC “B” High BLU/RED B+/0.8 V B+/0.8 V General Description and

Operation, IAC

A9 Automatic Transmission

Fluid (ATF) Lamp ORN/BLK B+ B+ Automatic Transmission

(4L30E)

A10 Winter Lamp PNK/GRN B+ B+ Automatic Transmission

(4L30E)

A11 Power Lamp PNK/WHT B+ B+ Automatic Transmission

(4L30E)

A12 Not Used

A13 Malfunction Indicator

(Check Engine or MIL)

Lamp

WHT/GRN 0.0 V B+ Chassis Electrical

A14 “Check Transmission”

Lamp Driver VIO B+ B+ Chassis Electrical

A15 EVAP Canister Purge

Signal RED/BLU B+ 5.7 V General Description and

Operation, EVAP Emission

Control System

A16 Band Apply YEL/BLK B+ B+ Automatic Transmission

(4L30E)

PCM Pinout Table, 32-Way Red Connector – Row “B”

TS23344

PIN PIN Function Wire Color IGN ON ENG RUN Refer To

B1 5 Volt Reference “B” BLU/ORN 5.0 V 5.0 V Appropriate Sensor

B2 Ignition coil #4 RED/WHT 0.0 V 0.1 V General Description and

Operation, ICM

B3 Ignition coil #2 RED/BLK 0.0 V 0.1 V General Description and

Operation, ICM

B4 Ignition coil #6 RED/GRN 0.0 V 0.1 V General Description and

Operation, ICM

B5 Not Used — — — —

B6 Not Used — — — —

B7 Exhaust Gas Recirculation

(EGR) YEL/RED 0.6 V 0.6 V General Description and

Operation, Linear EGR

Control

B8 Intake Air Temperature

(IAT) Sensor YEL/GRN ≈3 V

(depends on

temperature)

≈3 V

(depends on

temperature)

General Description and

Operation, IAT

B9 Not Used — — — —

B10 Not Used — — — —

B11 Power Steering Pressure

(PSP) Switch GRN/YEL B+ B+ General Description and

Operation, PSP

B12 Illuminated Switch GRN/YEL B+ B+ Chassis Electrical

B13 Class 2 Data ORN/BLK 0.0 V 0.0 V Diagnosis, Class 2 Serial

Data

B14 A/C Clutch GRY/RED B+ (A/C

OFF) B+ (A/C

OFF) General Description and

Operation, A/C Clutch Circuit

Operation

B15 Not Used — — — —

B16 Not Used — — — —

PCM Pinout Table, 32-Way White Connector – Row “C”

TS23345

PIN PIN Function Wire Color IGN ON ENG RUN Refer To

C1 Injector Cylinder #4 GRN/RED B+ B+ General Description and

Operation, Fuel Injector

C2 Shift “B” Solenoid BRN/BLK 0.0 V 0.0 V Automatic Transmission

(4L30E)

C3 Injector Cylinder #6 GRN/YEL B+ B+ General Description and

Operation, Fuel Injector

C4 Ignition Control (IC)

Cylinder #1 RED 0.0 V 0.1 V General Description and

Operation, Fuel Injector

C5 Crankshaft Position

Sensor, “A” Circuit YEL 0.3 V 2.2 V General Description and

Operation, Crankshaft

Position Sensor

C6 Not Used — — — —

C7 PCM Ground BLK/WHT 0.0 V 0.0 V Chassis Electrical

C8 PCM Ground BLK/RED 0.0 V 0.0 V Chassis Electrical

C9 PCM Ground BLK/BLU 0.0 V 0.0 V Chassis Electrical

C10 Tachometer BLK/RED 8.8 V 10.0 (at idle) Chassis Electrical

C11 Variable Intake Manifold WHT/BLU 0.0 V 0, B+ (More

than 3600

rpm)

Manual Transmission

C12 Rear Defogger Relay RED/WHT B+ B+ Chassis Electrical

C13 Not Used — — — —

C14 Bank 2 HO2S 1 High WHT 0.3 V 0.0-0.8 V General Description and

Operation, Fuel HO2S 1

C15 Bank 2 HO2S 1 Low RED 0.0 V 0.1 V General Description and

Operation, Fuel HO2S 1

C16 Not Used — — — —

PCM Pinout Table, 32-Way White Connector – Row “D”

TS23345

PIN PIN Function Wire Color IGN ON ENG RUN Refer To

D1 Injector Cylinder #2 GRN/ORN B+ B+ General Description and

Operation, Fuel Injector

D2 Torque Converter Clutch

(TCC) RED/YEL 0.0 V 0.0 V On-Vehicle Service, Torque

Converter Clutch

D3 Injector Cylinder #1 GRN/WHT B+ B+ General Description and

Operation, Fuel Injector

D4 Serial Data (8192) RED 5.0 V 5.0 V Chassis Electrical

D5 Ignition Control, Cylinder

#5 RED/YEL 0.0 V 0.1 V General Description and

Operation, Ignition Control

Module

D6 Ignition Control, Cylinder

#3 RED/BLU 0.0 V 0.1 V General Description and

Operation

D7 Speedometer BLU/BLK 0.0 V 0.1 V

(at rest) Chassis Electrical

D8 Sensor Ground 5V

Reference A Return GRN 0.0 V 0.0 V Appropriate Sensor

D9 Sensor Ground 5 V

Reference B Return GRN 0.0 V 0.0 V Appropriate Sensor

D10 Mass Air Flow (MAF) YEL 4.9 V 4.2 V General Description, Mass

Air Flow Sensor

D11 Camshaft Position Sensor BLU 5.0 V 4.6 V General Description and

Operation, Camshaft

Position Sensor

D12 Not Used — — — —

D13 Not Used — — — —

D14 Bank 1 HO2S 1 Low BLU 0.0 V 0.1 V General Description and

Operation, Fuel HO2S 1

D15 Bank 1 HO2S 1 High PNK 0.3 V 0.0-0.8 V General Description and

Operation, Fuel HO2S 1

D16 Not Used — — — —

PCM Pinout Table, 32-Way Blue Connector – Row “E”

TS23346

PIN PIN Function Wire Color IGN ON ENG RUN Refer To

E1 Vehicle Speed Sensor

Signal YEL 0.0 V 0.1 V Automatic Transmission

(4L30E)

E2 Vehicle Speed Sensor

Low BRN 0.0 V 0.0 V Automatic Transmission

(4L30E)

E3 Pressure Control Solenoid

Low RED/GRN 0.0 V 0.0 V Automatic Transmission

(4L30E)

E4 Pressure Control Solenoid

High RED/BLK 0.0 V 0.0 V Automatic Transmission

(4L30E)

E5 Exhaust Gas Recirculation

(EGR) Ignition BLK/YEL B+ B+ General Description and

Operation, EGR Control

E6 Exhaust Gas Recirculation

(EGR) Solenoid YEL B+ B+ General Description and

Operation, EGR Control

E7 Transmission Range

Signal “B” PNK 0.0 V 0.0 V Automatic Transmission

(4L30E)

E8 Throttle Position (TP)

Sensor BLU 0.6 V 0.6 V

(at idle) General Description and

Operation, Throttle Position

Sensor

E9 Engine Coolant

Temperature (ECT)

Sensor

BLU/RED 2.3 V 2.1 V General Description and

Operation, Engine Coolant

Temperature (ECT) Sensor

E10 Not Used — — — —

E11 Crankshaft Position (CKP)

Sensor +5 Volt Reference BRN 5.0 V 5.0 V General Description and

Operation, Crankshaft

Position Sensor

E12 Transmission Range

Signal “A” PNK/BLU B+ B+ Automatic Transmission

(4L30E)

E13 Fuel Pump (FP) Relay PNK/WHT 0.0 V B+ On-Vehicle Service, Fuel

Pump Relay

E14 Shift High (BAND APPLY) BRN/WHT B+ B+ Automatic Transmission

(4L30E)

E15 A/C Request GRN/BLK 0.0 V 0.0 V Electric Cooling Fans

E16 Ignition Feed (1 of 2 F16) RED/BLU B+ B+ —

PCM Pinout Table, 32-Way Blue Connector – Row “F”

TS23346

PIN PIN Function Wire Color IGN ON ENG RUN Refer To

F1 Not Used — — — —

F2 Transmission Range

Signal “C” BLU/WHT 0.0 V 0.0 V Automatic Transmission

(4L30E)

F3 Transmission Range

Signal “P” PNK/BLK B+ B+ Automatic transmission

(4L30E)

F4 Brake Switch RED 0.0 V 0.0 V Automatic transmission

(4L30E)

F5 Power Switch VIO B+ B+ Automatic Transmission

(4L30E)

F6 Winter Switch VIO B+ B+ Automatic T ransmission

(4L30E)

F7 Transmission Fluid

Temperature GRN/RED 2.2 V 1.1 V Automatic Transmission

(4L30E)

F8 Manifold Absolute

Pressure (MAP) GRY 4.7 V 1.1 V General Description and

Operation, Manifold Absolute

Pressure

F9 Rear Defogger Switch YEL/GRN B+ B+ Chassis Electrical

F10 Cruise Control GRY/BLU B+ B+ Automatic transmission

(4L30E)

F11 Kickdown Switch LT BLU B+ B+ Automatic Transmission

(4L30E)

F12 Diag ORN/BLU B+ B+ —

F13 Injector Cylinder #3 GRN B+ B+ General Description and

Operation, Fuel Injector

F14 Shift “A” Solenoid YEL/GRN B+ B+ Automatic Transmission

(4L30E)

F15 Injector Cylinder #5 GRN/BLK B+ B+ General Description and

Operation, Fuel Injector

F16 Ignition Feed (1 of 2 E16) RED/BLU B+ B+ —

Component Locators

Engine Component Locator

515RW017

Engine Component Locator Table

Number Name Location

1Crank Position (CKP) Sensor Lower right side of the cylinder block

2Linear Exhaust Gas Recirculation (EGR) Valve Rear right of the engine

3Knock Sensor Right hand side between right bank and left bank

of the cylinder block

4Manifold Absolute Pressure (MAP) Sensor Bolted to the top the upper intake manifold

5Common Chamber Top of the engine

6EVAP Canister Purge Valve Bolted to the front of the coolant pipe

7Fuel Pressure Regulator Rear right side of the engine

8Injection Coil Top of the cylinder engine

9Air Cleaner Left front of the engine bay

10 Mass Air Flow (MAF) Sensor Attached to the air filter box

11 Camshaft Position (CMP) Sensor On the rear side of the left cylinder head cover

12 Intake Air Temperature (IAT) Sensor On the intake air dukt near the throttle body

13 Throttle Position (TP) Sensor On the right of the throttle body

14 Engine Coolant Temperature (ECT) Sensor On the coolant crossover pipe at the front of the

engine,near the throttle body

15 Idle Air Control (IAC) Valve On the left of the throttle body

16 Positive Crankcase Ventilator (PCV) Valve On the left of the cylinder head

17 Fuse/Relay Box Along the inside of the right fender

Undercarriage Component Locator

014RW188

Undercarriage Component Locator Table

Number Name Location

1Heated Oxygen Sensor (Bank 2) Threated into the exhaust pipe ahead the

left–hand catalytic convertor

2 Fuel Filter Located along the inside of the right frame

rail,ahead of the propeller shaft

3Fuel Gauge Unit Installed in the top of the fuel tank

4Evaporative (EVAP) Canister On the top of the bracket that is located behind

of the cross member

5Vehicle Speed Sensor (VSS) Protrudes from the transmission housing, just

ahead of the fuel tank

6Heated Oxygen Sensor (Bank 1) Threated into the exhaust pipe ahead

theright–hand catalytic convertor

Sensors and Miscellaneous Component Locators

150RX023

014RW141

T321067

T321070

055RW003

041RW013

025RW008

T321078

060RW007

028RW001

Fuse and Relay Panel (Underhood Electrical Center)

755RX033

Diagnosis

Strategy-Based Diagnostics

The strategy-based diagnostic is a uniform approach to

repair all Electrical/Electronic (E/E) systems. The

diagnostic flow can always be used to resolve an E/E

system problem and is a starting point when repairs are

necessary. The following steps will instruct the technician

how to proceed with a diagnosis:

1.Verify the customer complaint.

DTo verify the customer complaint, the technician

should know the normal operation of the system.

2.Perform preliminary checks.

DConduct a thorough visual inspection.

DReview the service history.

DDetect unusual sounds or odors.

DGather diagnostic trouble code information to

achieve an effective repair.

3.Check bulletins and other service information.

DThis includes videos, newsletters, etc.

4.Refer to service information (manual) system

check(s).

D“System checks” contain information on a system

that may not be supported by one or more DTCs.

System checks verify proper operation of the

system. This will lead the technician in an

organized approach to diagnostics.

5.Refer to service diagnostics.

DTC Stored

Follow the designated DTC chart exactly to make an

effective repair.

No DTC

Select the symptom from the symptom tables. Follow the

diagnostic paths or suggestions to complete the repair.

You may refer to the applicable component/system check

in the system checks.

No Matching Symptom

1.Analyze the complaint.

2.Develop a plan for diagnostics.

3.Utilize the wiring diagrams and the theory of

operation.

Combine technician knowledge with efficient use of the

available service information.

Intermittents

Conditions that are not always present are called

intermittents. To resolve intermittents, perform the

following steps:

1.Observe history DTCs, DTC modes, and freezeframe

data.

2.Evaluate the symptoms and the conditions described

by the customer.

3.Use a check sheet or other method to identify the

circuit or electrical system component.

4.Follow the suggestions for intermittent diagnosis

found in the service documentation.

Most scan tools, such as the Tech 2, have data-capturing

capabilities that can assist in detecting intermittents.

No Trouble Found

This condition exists when the vehicle is found to operate

normally. The condition described by the customer may

be normal. Verify the customer complaint against another

vehicle that is operating normally. The condition may be

intermittent. Verify the complaint under the conditions

described by the customer before releasing the vehicle.

1.Re-examine the complaint.

When the complaint cannot be successfully found or

isolated, a re-evaluation is necessary. The complaint

should be re-verified and could be intermittent as

defined in

Intermittents

, or could be normal.

2.Repair and verify.

After isolating the cause, the repairs should be made.

Validate for proper operation and verify that the

symptom has been corrected. This may involve road

testing or other methods to verify that the complaint

has been resolved under the following conditions:

DConditions noted by the customer.

DIf a DTC was diagnosed, verify a repair by

duplicating conditions present when the DTC was

set as noted in the Failure Records or Freeze

Frame data.

Verifying Vehicle Repair

Verification of the vehicle repair will be more

comprehensive for vehicles with OBD II system

diagnostics. Following a repair, the technician should

perform the following steps:

IMPORTANT:Follow the steps below when you verify

repairs on OBD II systems. Failure to follow these steps

could result in unnecessary repairs.

1.Review and record the Failure Records and the

Freeze Frame data for the DTC which has been

diagnosed (Freeze Frame data will only be stored for

an A or B type diagnostic and only if the MIL (“Check

Engine” lamp) has been requested).

2.Clear the DTC(s).

3.Operate the vehicle within conditions noted in the

Failure Records and Freeze Frame data.

4.Monitor the DTC status information for the DTC which

has been diagnosed until the diagnostic test

associated with that DTC runs.

General Service Information

Non-OEM Parts

All of the OBD II diagnostics have been calibrated to run

with OEM parts. Something as simple as a

high-performance exhaust system that affects exhaust

system back pressure could potentially interfere with the

operation of the EGR valve and thereby turn on the MIL

(“Check Engine” lamp). Small leaks in the exhaust

system near the post catalyst oxygen sensor can also

cause the MIL (“Check Engine” lamp) to turn on.

Aftermarket electronics, such as transceiver, stereos,

and anti-theft devices, may radiate EMI into the control

system if they are improperly installed. This may cause a

false sensor reading and turn on the MIL (“Check Engine”

lamp).

Environment

Temporary environmental conditions, such as localized

flooding, will have an effect on the vehicle ignition system.

If the ignition system is rain-soaked, it can temporarily

cause engine misfire and turn on the MIL (“Check Engine”

lamp).

Emissions Control Information Label

The engine compartment “Vehicle Emissions Control

Information Label” contains important emission

specifications and setting procedures. In the upper left

corner is exhaust emission information. There is also an

illustrated emission components and vacuum hose

schematic.

This label is located in the engine compartment of every

vehicle. If the label has been removed it should be

replaced. It can be ordered from Isuzu Dealer ship.

Maitenance Schedule

Refer to the

Maintenance Schedule

Visual/Physical Engine Compartment

Inspection

Perform a careful visual and physical engine

compartment inspection when performing any diagnostic

procedure or diagnosing the cause of an emission test

failure. This can often lead to repairing a problem without

further steps. Use the following guidelines when

performing a visual/physical inspection:

DInspect all vacuum hoses for pinches, cuts,

disconnections, and proper routing.

DInspect hoses that are difficult to see behind other

components.

DInspect all wires in the engine compartment for proper

connections, burned or chafed spots, pinched wires,

contact with sharp edges or contact with hot exhaust

manifolds or pipes.

Basic Knowledge of Tools Required

NOTE: Lack of basic knowledge of this powertrain when

performing diagnostic procedures could result in an

incorrect diagnosis or damage to powertrain

components. Do not attempt to diagnose a powertrain

problem without this basic knowledge.

A basic understanding of hand tools is necessary to effec-

tively use this section of the Service Manual.

Seral Data Communications

Class II Serial Data Communications

Government regulations require that all vehicle

manufacturers establish a common communication

system. This vehicle utilizes the “Class II”

communication system. Each bit of information can have

one of two lengths: long or short. This allows vehicle

wiring to be reduced by transmitting and receiving

multiple signals over a single wire. The messages carried

on Class II data streams are also prioritized. If two

messages attempt to establish communications on the

data line at the same time, only the message with higher

priority will continue. The device with the lower priority

message must wait. The most significant result of this

regulation is that it provides Tech 2 manufacturers with

the capability to access data from any make or model

vehicle that is sold.

The data displayed on the other Tech 2 will appear the

same, with some exceptions. Some scan tools will only

be able to display certain vehicle parameters as values

that are a coded representation of the true or actual value.

For more information on this system of coding, refer to

Decimal/Binary/Hexadecimal Conversions.

On this

vehicle the Tech 2 displays the actual values for vehicle

parameters. It will not be necessary to perform any

conversions from coded values to actual values.

On-Board Diagnostic (OBD)

On-Board Diagnostic Tests

A diagnostic test is a series of steps, the result of which is

a pass or fail reported to the diagnostic executive. When

a diagnostic test reports a pass result, the diagnostic

executive records the following data:

DThe diagnostic test has been completed since the last

ignition cycle.

DThe diagnostic test has passed during the current

ignition cycle.

DThe fault identified by the diagnostic test is not

currently active.

When a diagnostic test reports a fail result, the diagnostic

executive records the following data:

DThe diagnostic test has been completed since the last

ignition cycle.

DThe fault identified by the diagnostic test is currently

active.

DThe fault has been active during this ignition cycle.

DThe operating conditions at the time of the failure.

Remember, a fuel trim DTC may be triggered by a list of

vehicle faults. Make use of all information available (other

DTCs stored, rich or lean condition, etc.) when

diagnosing a fuel trim fault.

Comprehensive Component Monitor

Diagnostic Operation

Input Components:

Input components are monitored for circuit continuity and

out-of-range values. This includes rationality checking.

Rationality checking refers to indicating a fault when the

signal from a sensor does not seem reasonable,

i.e.Throttle Position (TP) sensor that indicates high

throttle position at low engine loads or MAP voltage. Input

components may include, but are not limited to the

following sensors:

DVehicle Speed Sensor (VSS)

DCrankshaft Position (CKP) Sensor

DKnock Sensor (KS)

DThrottle Position (TP) Sensor

DEngine Coolant Temperature (ECT) Sensor

DCamshaft Position (CMP) Sensor

DManifold Absolute Pressure (MAP) Sensor

DMass Air Flow (MAF) Sensor

In addition to the circuit continuity and rationality check

the ECT sensor is monitored for its ability to achieve a

steady state temperature to enable closed loop fuel

control.

Output Components:

Output components are diagnosed for proper response to

control module commands. Components where

functional monitoring is not feasible will be monitored for

circuit continuity and out-of-range values if applicable.

Output components to be monitored include, but are not

limited to, the following circuit:

DIdle Air Control (IAC) Motor

DControl module controlled EVAP Canister Purge

Valve

DElectronic Transmission controls

DA/C relays

DCooling fan relay

DVSS output

DMIL control

Refer to PCM and Sensors in General Descriptions.

Passive and Active Diagnostic Tests

A passive test is a diagnostic test which simply monitors a

vehicle system or component. Conversely, an active test,

actually takes some sort of action when performing

diagnostic functions, often in response to a failed passive

test. For example, the EGR diagnostic active test will

force the EGR valve open during closed throttle decel

and/or force the EGR valve closed during a steady state.

Either action should result in a change in manifold

pressure.

Intrusive Diagnostic Tests

This is any on-board test run by the Diagnostic

Management System which may have an effect on

vehicle performance or emission levels.

Warm-Up Cycle

A warm-up cycle means that engine at temperature must

reach a minimum of 70°C (160°F)

and

rise at least 22°C

(40°F) over the course of a trip.

Freeze Frame

Freeze Frame is an element of the Diagnostic

Management System which stores various vehicle

information at the moment an emissions-related fault is

stored in memory and when the MIL is commanded on.

These data can help to identify the cause of a fault. Refer

Storing And Erasing Freeze Fame Data

for more

detailed information.

Failure Records

Failure Records data is an enhancement of the OBD II

Freeze Frame feature.Failure Records store the same

vehicle information as does Freeze Frame, but it will store

that information for any fault which is stored in on-board

memory, while Freeze Frame stores information only for

emission-related faults that command the MIL on.

Common OBD Terms

Diagnostic

When used as a noun, the word diagnostic refers to any

on-board test run by the vehicle’s Diagnostic

Management System. A diagnostic is simply a test run on

a system or component to determine if the system or

component is operating according to specification. There

are many diagnostics, shown in the following list:

DOxygen sensors

DOxygen sensor heaters

DEGR

Enable Criteria

The term “enable criteria” is engineering language for the

conditions necessary for a given diagnostic test to run.

Each diagnostic has a specific list of conditions which

must be met before the diagnostic will run. “Enable

criteria” is another way of saying “conditions required”.

The enable criteria for each diagnostic is listed on the first

page of the DTC description in Section 6E under the

heading “Conditions for Setting the DTC”. Enable criteria

varies with each diagnostic, and typically includes, but is

not limited to the following items:

Dengine speed

Dvehicle speed

DECT

DMAF/MAP

Dbarometric pressure

DIAT

DTP

DTCC enabled

DA/C on

Trip

Technically , a trip is a key on-run-key off cycle in which all

the enable criteria for a given diagnostic are met, allowing

the diagnostic to run. Unfortunately, this concept is not

quite that simple. A trip is official when all the enable

criteria for a given diagnostic are met. But because the

enable criteria vary from one diagnostic to another, the

definition of trip varies as well. Some diagnostic are run

when the vehicle is at operating temperature, some when

the vehicle first starts up; some require that the vehicle be

cruising at a steady highway speed, some run only when

the vehicle is idle; some diagnostics function with the

TCC disables. Some run only immediately following a

cold engine start-up.

A trip then, is defined as a key on-run-key off cycle in

which the vehicle was operated in such a way as to satisfy

the enabling criteria for a given diagnostic, and this

diagnostic will consider this cycle to be one trip. However ,

another diagnostic with a different set of enable criteria

(which were not met) during this driving event, would not

consider it a trip. No trip will occur for that particular

diagnostic until the vehicle is driven in such a way as to

meet all the enable criteria.

The Diagnostic Executive

The Diagnostic Executive is a unique segment of

software which is designed to coordinate and prioritize

the diagnostic procedures as well as define the protocol

for recording and displaying their results. The main

responsibilities of the Diagnostic Executive are listed as

follows:

DCommanding the MIL (“Check Engine” lamp) on and

off

DDTC logging and clearing

DFreeze Frame data for the first emission related DTC

recorded

DNon-emission related Service Lamp (future)

DOperating conditions Failure Records buffer, (the

number of records will vary)

DCurrent status information on each diagnostic

DSystem Status (I/M ready)

The Diagnostic Executive records DTCs and turns on the

MIL when emission-related faults occur. It can also turn

off the MIL if the conditions cease which caused the DTC

to set.

Diagnostic Information

The diagnostic charts and functional checks are designed

to locate a faulty circuit or component through a process

of logical decisions. The charts are prepared with the

requirement that the vehicle functioned correctly at the

time of assembly and that there are no multiple faults

present.

There is a continuous self-diagnosis on certain control

functions. This diagnostic capability is complemented by

the diagnostic procedures contained in this manual. The

language of communicating the source of the malfunction

is a system of diagnostic trouble codes. When a

malfunction is detected by the control module, a

diagnostic trouble code is set and the Malfunction

Indicator Lamp (MIL) (“Check Engine” lamp) is

illuminated.

Malfunction Indicator Lamp (MIL)

The Malfunction Indicator Lamp (MIL) looks the same as

the MIL you are already familiar with (“Check Engine”

lamp). However, OBD requires that it illuminate under a

strict set of guide lines.

Basically, the MIL is turned on when the PCM detects a

DTC that will impact the vehicle emissions.

The MIL is under the control of the Diagnostic Executive.

The MIL will be turned on if an emissions-related

diagnostic test indicates a malfunction has occurred. It

will stay on until the system or component passes the

same test, for three consecutive trips, with no emission

srelated faults.

Extinguishing the MIL

When the MIL is on, the Diagnostic Executive will turn off

the MIL after

three(3) consecutive

trips that a “test

passed” has been reported for the diagnostic test that

originally caused the MIL to illuminate.

Although the MIL has been turned off, the DTC will remain

in the PCM memory (both Freeze Frame and Failure

Records) until

forty(40) warm-up cycles after no faults

have been completed.

If the MIL was set by either a fuel trim or misfire-related

DTC, additional requirements must be met. In addition to

the requirements stated in the previous paragraph, these

requirements are as follows:

DThe diagnostic tests that are passed must occur with

375 RPM of the RPM data stored at the time the last

test failed.

DPlus or minus ten (10) percent of the engine load that

was stored at the time the last failed.

DSimilar engine temperature conditions (warmed up or

warming up ) as those stored at the time the last test

failed.

Meeting these requirements ensures that the fault which

turned on the MIL has been corrected.

The MIL (“Check Engine” lamp) is on the instrument

panel and has the following functions:

DIt informs the driver that a fault that affects vehicle

emission levels has occurred and that the vehicle

should be taken for service as soon as possible.

DAs a bulb and system check, the MIL will come “ON”

with the key “ON” and the engine not running. When

the engine is started, the MIL will turn “OFF.”

DWhen the MIL remains “ON” while the engine is

running, or when a malfunction is suspected due to a

driveability or emissions problem, a Powertrain

On-Board Diagnostic (OBD) System Check must be

performed. The procedures for these checks are

given in On-Board Diagnostic (OBD) System Check.

These checks will expose faults which may not be

detected if other diagnostics are performed first.

DTC Types

Each DTC is directly related to a diagnostic test. The

Diagnostic Management System sets DTC based on the

failure of the tests during a trip or trips. Certain tests must

fail two (2) consecutive trips before the DTC is set. The

following are the four (4) types of DTCs and the

characteristics of those codes:

DType A

DEmissions related

DRequests illumination of the MIL of the first trip with a

fail

DStores a History DTC on the first trip with a fail

DStores a Freeze Frame (if empty)

DStores a Fail Record

DUpdates the Fail Record each time the diagnostic

test fails

DType B

DEmissions related

D“Armed” after one (1) trip with a fail

D“Disarmed” after one (1) trip with a pass

DRequests illumination of the MIL on the

second

consecutive trip

with a fail

DStores a History DTC on the second consecutive trip

with a fail (The DTC will be armed after the first fail)

DStores a Freeze Frame on the second consecutive

trip with a fail (if empty)

DStores a Fail Record when the first test fails (not

dependent on

consecutive trip

fails)

DUpdates the Fail Record each time the diagnostic

test fails

(Some special conditions apply to misfire and fuel trim

DTCs)

DType C (if the vehicle is so equipped)

DNon-Emissions related

DRequests illumination of the Service Lamp or the

service message on the Drive Information Center

(DIC) on the

first trip

with a fail

DStores a History DTC on the

first trip

with a fail

Does not

store a Freeze Frame

DStores Fail Record when test fails

DUpdates the Fail Record each time the diagnostic

test fails

DType D (

Type D

non-emissions related are not utilized

on certain vehicle applications).

DNon-Emissions related

DDose not request illumination of any lamp

DStores a History DTC on the

first trip

with a fail

Does not

store a Freeze Frame

DStores Fail Record when test fails

DUpdates the Fail Record each time the diagnostic

test fails

Only four Fail Records can be stored. Each Fail Record

is for a different DTC. It is possible that there will not be

Fail Records for every DTC if multiple DTCs are set.

Storing and Erasing Freeze Frame Data and Failure

Records

Government regulations require that engine operating

conditions be captured whenever the MIL is illuminated.

The data captured is called Freeze Frame data. The

Freeze Frame data is very similar to a single record of

operating conditions. Whenever the MIL is illuminated,

the corresponding record of operating conditions is

recorded to the Freeze Frame buffer.

Freeze Frame data can only be overwritten with data

associated with a misfire or fuel trim malfunction. Data

from these faults take precedence over data associated

with any other fault. The Freeze Frame data will not be

erased unless the associated history DTC is cleared.

Each time a diagnostic test reports a failure, the current

engine operating conditions are recorded in the

Failure

Records

buffer. A subsequent failure will update the

recorded operating conditions. The following operating

conditions for the diagnostic test which failed

typically

include the following parameters:

DAir Fuel Ratio

DAir Flow Rate

DEngine Speed

DEngine Load

DEngine Coolant Temperature

DVehicle Speed

DTP

DMAP/BARO

DInjector Base Pulse Width

DLoop Status

Intermittent Malfunction Indicator Lamp

In the case of an “intermittent” fault, the MIL (“Check

Engine” lamp) may illuminate and then (after three trips)

go “OFF”. However , the corresponding diagnostic trouble

code will be stored in the memory. When unexpected

diagnostic trouble codes appear, check for an intermittent

malfunction.

A diagnostic trouble code may reset. Consult the

“Diagnostic Aids” associated with the diagnostic trouble

code. A physical inspection of the applicable sub–system

most often will resolve the problem.

Data Link Connector (DLC)

The provision for communication with the contorl module

is the Data Link Connector (DLC). It is located at the

lower left of the instrument panel. The DLC is used to

connect to the Tech 2 Scan Tool. Some common uses of

the Tech 2 are listed below:

DIdentifying stored Diagnostic T rouble Codes (DTCs).

DClearing DTCs.

DPerforming out put control tests.

DReading serial data.

TS24064

Verifying Vehicle Repair

Verification of vehicle repair will be more comprehensive

for vehicles with OBD II system diagnostic. Following a

repair, the technician should perform the following steps:

1.Review and record the Fail Records and/or Freeze

Frame data for the DTC which has been diagnosed

(Freeze Frame data will only be stored for an A or B

type diagnostic and only if the MIL has been

requested).

2.Clear DTC(s).

3.Operate the vehicle within conditions noted in the Fail

Records and/or Freeze Frame data.

4.Monitor the DTC status information for the DTC which

has been diagnosed until the diagnostic test

associated with that DTC runs.

Following these steps are very important in verifying

repairs on OBD systems. Failure to follow these steps

could result in unnecessary repairs.

Reading Diagnostic Trouble Codes Using

the TECH 2 Scan Tool

The procedure for reading diagnostic trouble code(s) is to

use a diagnostic Scan Tool. When reading DTC(s), follow

instructions supplied by tool manufacturer.

For the 1998 model year, Isuzu dealer service

departments will continue to use Tech 2.

Clearing Diagnostic Trouble Codes

IMPORTANT:Do not clear DTCs unless directed to do

so by the service information provided for each diagnostic

procedure. When DTCs are cleared, the Freeze Frame

and Failure Record data which may help diagnose an

intermittent fault will also be erased from memory.

If the fault that caused the DTC to be stored into memory

has been corrected, the Diagnostic Executive will begin to

count the “warm-up” cycles with no further faults

detected, the DTC will automatically be cleared from the

PCM memory.

To clear Diagnostic Trouble Codes (DTCs), use the

diagnostic Scan Tool “clear DTCs” or “clear information”

function. When clearing DTCs follow instructions

supplied by the tool manufacturer.

When a Tech 2 is not available, DTCs can also be cleared

by disconnecting

one

of the following sources for at least

thirty (30) seconds.

NOTE: To prevent system damage, the ignition key must

be “OFF” when disconnecting or reconnecting battery

power.

DThe power source to the control module. Examples:

fuse, pigtail at battery PCM connectors etc.

DThe negative battery cable. (Disconnecting the

negative battery cable will result in the loss of other

on-board memory data, such as preset radio tuning).

Tech 2

From 98 MY, Isuzu dealer service departments are

recommended to use the Tech 2 Scan Tool. Please refer

to the Tech 2 user guide.

901RW180

Legend

(1) PCMCIA Card

(2) RS 232 Loop Back Connector

(3) SAE 16/19 Adaptor

(4) DLC Cable

(5) Tech–2

Tech 2 Features

1.Tech 2 is a 12 volt system. Do not apply 24 volt.

2.After connecting and/or installing, the Vehicle

Communications Interface (VCI) module, PCMCIA

card and DLC connector to the Tech 2, connect the

tool to the vehicle DLC.

3.Make sure the Tech 2 is powered OFF when

removing or installing the PCMCIA card.

4.The PCMCIA card has a capacity of 10 Megabytes

which is 10 times greater than the memory of the T ech

1 Mass Storage Cartridge.

5.The Tech 2 has the capability of two snapshots.

6.The PCMCIA card is sensitive to magnetism and

static electricity, so care should be taken in the

handling of the card.

7.The Tech 2 can plot a graph when replaying a

snapshot.

8.Always return to the Main Menu by pressing the EXIT

key several times before shutting down.

9.To clear Diagnostic Trouble Codes (DTCs), open

Application Menu and press “F1: Clear DTC Info”.

Getting Started

DBefore operating the Isuzu PCMCIA card with the

Tech 2, the following steps must be performed:

1.The Isuzu 99 System PCMCIA card (1) inserts into

the Tech 2 (5).

2.Connect the SAE 16/19 adapter (3) to the DLC cable

(4).

3.Connect the DLC cable to the Tech 2 (5)

4.Make sure the vehicle ignition is off.

5.Connect the Tech 2 SAE 16/19 adapter to the vehicle

DLC.

810RW317

6.Turn on the vehicle ignition.

7.Power the Tech 2 ON and V erify the Tech 2 power up

display.

060RW009

NOTE: The RS232 Loop back connector is only to use for

diagnosis of Tech 2. Refer to user guide of the Tech 2.

Operating Procedure (For Example)

The power up screen is displayed when you power up the

tester with the Isuzu systems PCMCIA card. Follow the

operating procedure below.

060RX060

060RX086

DThe following table shows which functions are used

for the available equipment versions.

060RW224

DTC Modes

060RW229

On OBD II vehicles there are five options available in T ech

2 DTC mode to display the enhanced information

available. After selecting DTC, the following menu

appears:

DDTC Info

DFreeze Frame

DFail Records (not all applications)

DClear Info

060RW223

The following is a brief description of each of the sub

menus in DTC Info and DTC. The order in which they

appear here is alphabetical and not necessarily the way

they will appear on the Tech 2.

DTC Information Mode

Use the DTC info mode to search for a specific type of

stored DTC information. There are six choices. The

service manual may instruct the technician to test for

DTCs in a certain manner. Always follow published

service procedures.

060RW221

DTC Status

This selection will display any DTCs that have not run

during the current ignition cycle or have reported a test

failure during this ignition up to a maximum of 33 DTCs.

DTC tests which run and pass will cause that DTC

number to be removed from Tech 2 screen.

Fail This Ignition

This selection will display all DTCs that have failed during

the present ignition cycle.

History

This selection will display only DTCs that are stored in the

PCM’s history memory. It will display all type A and B

DTCs that have requested the MIL and have failed within

the last 40 warm-up cycles. In addition, it will display all

type C and type D DTCs that have failed within the last 40

warm-up cycles.

Last Test Failed

This selection will display only DTCs that have failed the

last time the test ran. The last test may have run during a

previous ignition cycle if a type A or type B DTC is

displayed. For type C and type D DTCs, the last failure

must have occurred during the current ignition cycle to

appear as Last Test Fail.

MILSVC or Message Request

This selection will display only DTCs that are requesting

the MIL. Type C and type D DTCs cannot be displayed

using this option. This selection will report type B DTCs

only after the MIL has been requested.

Not Run Since Code Cleared

This option will display up to 33 DTCs that have not run

since the DTCs were last cleared. Since any displayed

DTCs have not run, their condition (passing or failing) is

unknown.

Test Failed Since Code Cleared

This selection will display all active and history DTCs that

have reported a test failure since the last time DTCs were

cleared. DTCs that last failed more than 40 warm-up

cycles before this option is selected will not be displayed.

Miscellaneous Test

This test consists of eight menus-Lights, Relays, EVAP,

IAC System, Fuel System, EGR Control, Variable Intake

Manifold Solenoid, and Injector Balance Tests.

In these tests, Tech 2 sends operating signals to the

systems to confirm their operations thereby to judge the

normality of electric circuit.

To judge intermittent trouble,

1.Confirm DTC freeze frame data, and match the

freeze frame data as test conditions with the data list

displayed by Miscellaneous Test.

2.Confirm DTC setting conditions, and match the

setting conditions as test conditions with the data list

displayed by Miscellaneous Test.

3.Refer to the latest Service Bulletin.

Check to see if the Latest software is released or not.

And then Down Load the LATEST PROGRAMMED

SOFTWARE to the replacement PCM.

Lamps Test

This test is conducted check MIL and Low Fuel Lamp for

its working.

Tech2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Run the Engine at idle.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4.Select F0:Lamps Test in the Miscellaneous Test.

060RX035

5.Select F0:Malfunction Indicator Lamp.

060RX019

6.Push “On” soft key.

7.Make sure Lamp illuminates.

8.If lamp illuminates, the Lamp is operating correctly.

F1: Low Fuel Lamp is not used.

Relays Test

This test is conducted to check Fuel Pump Relay and A/C

Clutch for proper operation.

Tech 2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Ignition SW is “On”.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4.Select F1:Relay Test in the Miscellaneous Test.

060RX034

5.Select F0:Fuel Pump Relay.

060RX021

6.Push “On” soft key.

060RX022

7.Control Fuel Pump Relay and check data list.

8.If the data list changes, the Fuel Pump Relay is

normal.

9.Select F1:A/C Clutch Relay.

10.*Run the Engine at idle.

11.T urn on Air Condtioning.

060RX023

12.Push “On” and “Off” soft keys.

13.Control A/C Clutch Relay and check data list.

14.If the data list changes, the A/C Clutch Relay is

normal.

EVAP Test

This test is conducted check EV AP system for its working.

Tech 2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Run the Engine at idle.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4.Select F2:EVAP Test in the Miscellaneous Test.

060RX036

5.Select F0: Purge Solenoid.

060RX025

6.Push “Decrease” or “Increase” soft key.

060RX026

7.Control EVAP Purge Solenoid and check data list.

8.If the data list changes, the Purge Solenoid is normal.

F1: Vent Solenoid is not used.

Idle Air Control System Test

This test is conducted to check IAC system for proper

operation.

Tech 2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Run the Engine at idle.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4.Select F3: IAC System Test in the Miscellaneous

Test.

060RX007

5.Select F1: IAC Control Test.

060RW235

6.Push “Increase” or “Decrease” soft key.

7.Instruct IAC system and check data list.

060RX015

8.If the data list changes, the IAC control is normal.

9.Select F0: RPM Control Test

060RX016

10.Push “Increase” or “Decrease” soft key.

11.Control RPM and check data list.

12.If the data list changes, the RPM control is normal.

13.Select F2: IAC Reset.

14.Push “Reset IAC” soft key.

15.Control IAC Reset and check data list.

16.If data list changes, the IAC has been Reset.

060RW231–1

Fuel System Test

This test is conducted check Fuel Level Gauge for proper

operation.

Tech 2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Ignition SW is “On”.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4.Select F4: Fuel System in the Miscellaneous Menu.

060RX032

5.Select F0: Fuel Trim Reset.

060RX028

F1: Fuel Gauge Level is not used.

6.Push “Reset” soft key.

060RX029

EGR Control Test

This test is conducted check EGR valve for proper

operation.

Tech 2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Run the Engine at idle.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4. Select F5: EGR Control Test in the Miscellaneous

Test.

060RX008

5.Control EGR Valve and check data list.

060RX017

6.If data list chouges, the EGR Control is normal.

Variable Intake Manifold Solenoid Test

This test is conducted check VIM Solenoid for proper

operation.

Tech 2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Ignition SW is “On”.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4.Select F6: Variable Intake Manifold Solenoid Test.

060RX033

5.Push “On” or “Off” soft key.

060RX028

6.Control VIM Solenoid and check data list.

7.If data list changes, the VIM Solenoid is normal.

Injector Balance Test

This test is conducted to make sure the appropriate

electric signals are being sent to injectors Nos. 1–6.

Tech 2 must be used for this test.

Test Procedure:

1.Connect Tech 2 to the vehicle DLC.

2.Run the Engine at idle.

3.Select F3: Miscellaneous Test in the Application

Menu.

060RW228

4.Select F7: Injector Balance Test in the Miscellaneous

Test.

060RX006

5.Select injector number and push “injector off” of soft

key.

060RW230–1

6.Make sure of engine speed change.

7.If engine speed changes, the injector electric circuit is

normal.

If engine speed does not changes, the injector electric

circuit or the injector itself is not normal.

Plotting Snapshot Graph

This test selects several necessary items from the data

list to plot graphs and makes data comparison on a long

term basis. It is an effective test particularly in emission

related evaluations.

060RX037

For trouble diagnosis, you can collect graphic data (snap

shot) directly from the vehicle. You can replay the

snapshot data as needed. Therefore, accurate diagnosis

is possible, even though the vehicle is not available.

Plotting Graph Flow Chart (Plotting graph after obtaining vehicle information)

060RX085

Flow Chart for Snapshot Replay (Plotting Graph)

060RX040

Primary System-Based Diagnostics

There are primary system-based diagnostics which

evaluate system operation and its effect on vehicle

emissions. The primary system-based diagnostics are

listed below with a brief description of the diagnostic

function:

Oxygen Sensor Diagnosis

The fuel control heated oxygen sensors (Bank 1 HO2S 1

and Bank 2 HO2S 1) are diagnosed for the following

conditions:

DHeater performance (time to activity on cold start)

DSlow response

DResponse time (time to switch R/L or L/R)

DInactive signal (output steady at bias voltage –

approx. 450 mV)

DSignal fixed high

DSignal fixed low

If the oxygen sensor pigtail wiring, connector or terminal

are damaged, the entire oxygen sensor assembly must

be replaced. DO NOT attempt to repair the wiring,

connector or terminals. In order for the sensor to function

properly, it must have clean reference air provided to it.

This clean air reference is obtained by way of the oxygen

sensor wire(s). Any attempt to repair the wires, connector

or terminals could result in the obstruction of the

reference air and degrade oxygen sensor performance.

Refer to

On-Vehicle Service Heated Oxygen Sensors.

Fuel Control Heated Oxygen Sensors

The main function of the fuel control heated oxygen

sensors is to provide the control module with exhaust

stream oxygen content information to allow proper fueling

and maintain emissions within mandated levels. After it

reaches operating temperature, the sensor will generate

a voltage, inversely proportional to the amount of oxygen

present in the exhaust gases. The control module uses

the signal voltage from the fuel control heated oxygen

sensors while in closed loop to adjust fuel injector pulse

width. While in closed loop, the PCM can adjust fuel

delivery to maintain an air/fuel ratio which allows the best

combination of emission control and driveability . The fuel

control heated oxygen sensors are also used to

determine catalyst efficiency.

HO2S Heater

Heated oxygen sensors are used to minimize the amount

of time required for closed loop fuel control to begin

operation and to allow accurate catalyst monitoring. The

oxygen sensor heater greatly decreases the amount of

time required for fuel control sensors (Bank 1 HO2S 1 and

Bank2 HO2S 1) to become active.

On-Board Diagnostic (OBD) System Check

D06RX010

Circuit Description

The on-board diagnostic system check is the starting

point for any driveability complaint diagnosis. Before

using this procedure, perform a careful visual/physical

check of the PCM and engine grounds for cleanliness and

tightness.

The on-board diagnostic system check is an organized

approach to identifying a problem created by an

electronic engine control system malfunction.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside the

insulation. Check for poor connections or a damaged

harness. Inspect the PCM harness and connector for

improper mating, broken locks, improperly formed or

damaged terminals, poor terminal-to-wire connection,

and damaged harness.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart:

1. The MIL (“Check Engine” lamp) should be “ON”

steady with the ignition “ON”/engine “OFF.” If not,

the “No MIL” chart should be used to isolate the

malfunction.

2. Checks the Class 2 data circuit and ensures that the

PCM is able to transmit serial data.

3. This test ensures that the PCM is capable of

controlling the MIL (“Check Engine” lamp) and the

MIL (“Check Engine” lamp) driver circuit is not

shorted to ground.

4. If the engine will not start, the

Cranks But Will Not

Run

chart should be used to diagnose the condition.

7. A Tech 2 parameter which is not within the typical

range may help to isolate the area which is causing

the problem.

On- Board Diagnostic (OBD) System Check

Step Action Value(s) Yes No

1 1. Ignition “ON,” engine “OFF.”

2. Observe the malfunction indicator lamp (MIL or

“Check Engine lamp”).

Is the MIL (“Check Engine lamp”)“ON?” —Go to

Step 2

Go to

No MIL

(“Check

Engine” lamp)

21. Ignition “OFF.”

2. Install Tech 2.

3. Ignition “ON.”

4. Attempt to display PCM engine data with the T ech 2.

Does the Tech 2 display PCM data? —Go to

Step 3

Go to

Step 8

31. Using the Tech 2 output tests function, select MIL

(“Check Engine lamp”) dash lamp control and

command the MIL (“Check Engine lamp”) “OFF.”

(Refer to Miscellaneous Test)

2. Observe the MIL (“Check Engine lamp”).

Did the MIL (“Check Engine lamp”) turn “OFF?” —Go to

Step 4

Go to

MIL

(“Check

Engine” lamp)

On Steady

4Attempt to start the engine.

Did the engine start and continue to run? —Go to

Step 5

Go to

Cranks

But Will Not

Run

5Select “Display DTCs” with the Tech 2.

Are any DTCs stored? —Go to

Step 6

Go to

Step 7

6Are two or more of the following DTCs stored? P0107,

P0108, P0113, P0118, P0122, P0123, P0712, P1404.

—

Go to

“Multiple

PCM

Information

Sensor DTCs

Set”

Go to

applicable

DTC table

7Compare PCM data values displayed on the Tech 2 to

the typical engine scan data values.

Are the displayed values normal or close to the typical

values? —Go to

Symptom

Refer to

indicated

Component

System

Checks

81. Ignition “OFF,” disconnect the PCM.

2. Ignition “ON,” engine “OFF.”

3. Check the Class 2 data circuit for an open, short to

ground, or short to voltage. Also, check the DLC

ignition feed circuit for an open or short to ground

and the DLC ground circuit for an open.

4. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 2

Go to

Step 9

9Replace the PCM.

Is the action complete? —Go to

Step 2

—

A/C Clutch Control Circuit Diagnosis

D06RX011

Circuit Description

When air conditioning and blower fan are selected, and if

the system has a sufficient refrigerant charge, a 12-volt

signal is supplied to the A/C request input of the

powertrain control module (PCM). The A/C request

signal may be temporarily canceled during system

operation by the electronic thermostat in the evaporator

case. The electronic thermostat may intermittently

remove the control circuit ground for the A/C thermostat

relay to prevent the evaporator from forming ice. When

the A/C request signal is received by the PCM, the PCM

supplies a ground from the compressor clutch relay if the

engine operating conditions are within acceptable

ranges. With the A/C compressor relay energized,

voltage is supplied to the compressor clutch coil.

The PCM will enable the compressor clutch to engage

whenever A/C has been selected with the engine running,

unless any of the following conditions are present:

DThe throttle is greater than 90%.

DThe ignition voltage is below 10.5 volts.

DThe engine speed is greater than 4500 RPM for 5

seconds or 5400 RPM.

DThe engine coolant temperature (ECT) is greater

than 125 °C (257 °F).

DThe intake air temperature (IAT) is less than 5°C

(41°F).

DThe power steering pressure switch signals a high

pressure condition.

Diagnostic Aids

To diagnose an intermittent fault, check for the following

conditions:

DPoor connection at the PCM–Inspect connections for

backed-out terminals, improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

DDamaged harness–Inspect the wiring harness for

damage. If the harness appears to OK, observe the

A/C clutch while moving connectors and wiring

harnesses related to the A/C. A sudden clutch

malfunction will indicate the source of the intermittent

fault.

A/C Clutch Diagnosis

This chart should be used for diagnosing the electrical

portion of the A/C compressor clutch circuit. A Tech 2 will

be used in diagnosing the system. The Tech 2 has the

ability to read the A/C request input to the PCM. The Tech

2 can display when the PCM has commanded the A/C

clutch “ON.” The Tech 2 should have the ability to

override the A/C request signal and energize the A/C

compressor relay.

Test Description

IMPORTANT:Do not engage the A/C compressor

clutch with the engine running if an A/C mode is not

selected at the A/C control switch.

The numbers below refer to the step numbers on the

Diagnostic Chart:

3. This a test determine is the problem is with the

refrigerant system. If the switch is open, A/C

pressure gauges will be used to determine if the

pressure switch is faulty or if the system is partially

discharged or empty.

4. Although the normal complaint will be the A/C clutch

failing to engage, it is possible for a short circuit to

cause the clutch to run when A/C has not been

selected. This step is a test for that condition.

7. There is an extremely low probability that both relays

will fail at the same time, so the substitution process

is one way to check the A/C Thermostat relay. Use

a known good relay to do a substitution check.

9. The blower system furnishes a ground for the A/C

control circuit, and it also shares a power source

through the Heater and A/C Relay. The blower

must be “ON” in order to test the A/C system.

A/C Clutch Control Circuit Diagnosis

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Are any other DTCs stored?

—

Go to the

other DTC

chart(s) first Go to

Step 3

31. Disconnect the electrical connector at the pressure

switch located on the receiver/drier.

2. Use an ohmmeter to check continuity across the

pressure switch (BRN to GRN/WHT).

Is the pressure switch open? —

Go to Air

Conditioning

to diagnose

the cause of

the open

pressure

switch Go to

Step 4

StepNoYesValue(s)Action

4IMPORTANT:Before continuing with the diagnosis, the

following conditions must be met:

DThe intake air temperature must be greater than

15°C. (60°F).

DThe engine coolant temperature must be less

than 119°C (246°F).

1. A/C “OFF.”

2. Start the engine and idle for 1 minute.

3. Observe the A/C compressor.

Is the A/C compressor clutch engaged even though

A/C has not been requested? —Go to

Step 45

Go to

Step 5

51. Idle the engine.

2. A/C “ON”.

3. Blower “ON”.

4. Observe the A/C compressor.

Is the A/C compressor magnetic clutch engaged? —

Refer to

Diagnostic

Aids

Go to

Step 6

61. Engine idling.

2. A/C “ON”.

3. Blower “ON”.

4. Observe the “A/C Request” display on the Tech 2.

(Refer to the miscelluneous test)

Does the “A/C Request” display indicate “Yes?” —Go to

Step 34

Go to

Step 7

7Temporarily substitute the A/C compressor relay in

place of the A/C thermostat relay, then repeat Step 5.

Did the “A/C Request” display indicate “Yes?” —Go to

Step 8

Go to

Step 9

8Replace the original A/C thermostat relay.

Is the action complete? — Verify repair —

9Dose the blower operate? —Go to

Step 10

Go to

Step 11

10 Repair the blower.

Is the action complete? — Verify repair —

11 Check for a faulty 10A A/C fuse in the passenger

compartment fuse panel.

Was the 10A fuse OK? —Go to

Step 13

Go to

Step 12

12 Check for short circuit and make repairs if necessary.

Replace the 10A A/C fuse.

Is the action complete? — Verify repair —

13 1. Ignition “ON.”

2. Use a DVM to check voltage at the positive A/C

switch wire (BRN).

Was voltage equal to the specified value? B+ Go to

Step 15

Go to

Step 14

14 Repair the open wire (BRN) between the A/C switch

and the A/C fuse.

Is the action complete? — Verify repair —

Step NoYesValue(s)Action

15 1. Remove the glove box to gain access to the A/C

thermostat.

2. Disconnect the thermostat connector.

3. Attach a fused jumper between ground and the

GRN/RED wire at the thermostat.

4. A/C “ON.”

5. Blower “ON.”

Dose A/C request indicate “YES” on the Tech 2? —Go to

Step 16

Go to

Step 23

16 1. Ignition “ON.”

2. A/C switch “ON”.

3. Use a DVM to check voltage at the electronic A/C

thermostat.

Was voltage equal to the specified value? B+ Go to

Step 20

Go to

Step 17

17 Check for an open (LT GRN/BLK) wire between the

thermostat and the A/C switch.

Was the wire open? —Go to

Step 18

Go to

Step 19

18 Repair the open wire (LT GRN/BLK) between the

thermostat and the A/C switch.

Is the action complete? — Verify repair —

19 Replace the A/C switch.

Is the action complete? — Verify repair —

20 Use an ohmmeter to check continuity between the

electronic A/C thermostat and the blower switch.

Was there an open circuit? —Go to

Step 21

Go to

Step 22

21 Repair the open wire (WHT) between the thermostat

and the blower switch.

Is the action complete? — Verify repair —

22 Replace the electronic A/C thermostat.

Is the an action complete? — Verify repair —

23 Check for an open circuit between A/C thermostat relay

and PCM A/C request terminal (E-15).

Was there an open circuit? —Go to

Step 24

Go to

Step 25

24 Repair the open circuit between the PCM and A/C

thermostat relay.

Is the action complete? — Verify repair —

25 Check for an open circuit between the engine device

fuse and the A/C thermostat relay (WHT/GRN).

Was there an open circuit? —Go to

Step 26

Go to

Step 27

26 Repair the open circuit between the engine device fuse

and the A/C thermostat relay.

Is the action complete? — Verify repair —

27 1. Ignition “ON.”

2. Use a DVM to check voltage at the A/C pressure

switch (BRN).

Was voltage equal to the specified value? B+ Go to

Step 29

Go to

Step 28

Step NoYesValue(s)Action

28 Repair the open circuit between the 10A A/C fuse and

the pressure switch.

Is the action complete? — Verify repair —

29 Use an ohmmeter to check continuity between the

pressure switch (GRN/WHT) and the A/C thermostat

relay (GRN/WHT).

Was the circuit open? —Go to

Step 30

Go to

Step 31

30 Repair the open circuit between the pressure switch

and the A/C thermostat relay.

Is the action complete? — Verify repair —

31 Check for damaged pin or terminal at E-15 of the PCM.

Was a damaged pin or terminal found? —Go to

Step 32

Go to

Step 33

32 Repair the damaged pin or terminal.

Is the action complete? — Verify repair —

33 Replace the PCM.

Is the action complete? — Verify repair —

34 1. Remove the A/C compressor relay.

2. Ignition “ON.”

3. Use a DVM to check voltage at both of the BRN

wires at the A/C compressor relay socket.

Is the voltage equal to the specified value? B+ Go to

Step 36

Go to

Step 35

35 Repair the faulty BRN wire between the A/C fuse and

the A/C compressor relay .

Is the action complete? — Verify repair —

36 1. A/C compressor relay removed.

2. Engine idling.

3. A/C “ON.”

4. Blower “ON.”

5. Use a DVM to measure voltage between the

GRY/RED wire at the A/C compressor relay socket

and battery+.

Did the DVM indicate the specified value? B+ Go to

Step 40

Go to

Step 37

37 Check for an open GRY/RED wire between PCM

terminal B-14 and the A/C compressor relay.

Was the wire open? —Go to

Step 38

Go to

Step 39

38 Repair the open GRY/RED wire between the PCM and

the A/C compressor relay.

Is the action complete? — Verify repair —

39 Check for a damaged pin or terminal at B-14 of the

PCM.

Was a damaged pin or a terminal found? —Go to

Step 32

Go to

Step 33

Step NoYesValue(s)Action

40 1. A/C compressor relay removed.

2. Connect a fused jumper at the A/C compressor

relay socket between either BRN wire and the

BRN/YEL wire.

3. Engine idling.

4. A/C “ON.”

5. Blower “ON.”

Did the compressor magnetic clutch engage? —Go to

Step 41

Go to

Step 42

41 Repair the A/C compressor relay.

Is the action complete? — Verify repair —

42 Check for an open circuit between the A/C compressor

relay and the A/C clutch.

Was an open circuit found? —Go to

Step 43

Go to

Step 44

43 Repair the open circuit between the compressor Clutch

and the A/C compressor relay.

Is the action complete? — Verify repair —

44 Service the compressor clutch or replace the

compressor due to a faulty internal overheat switch.

Is the action complete? — Verify repair —

45 1. Remove the A/C compressor relay.

2. Idle the engine.

Is the compressor clutch still engaged when A/C is not

selected? — Go to

Step 46

Go to

Step 47

46 Repair the short to voltage between the A/C clutch and

A/C compressor relay.

Is the action complete? — Verify repair —

47 1. Reinstall the A/C compressor relay.

2. Remove the A/C thermostat relay.

3. Engine idling.

Is the compressor clutch still engaged when A/C is not

selected? — Go to

Step 48

Go to

Step 50

48 Use a DVM to check for a short to ground between the

A/C compressor relay and B-14 of the PCM.

Was a short detected? —Go to

Step 49

Go to

Step 33

49 Repair the short to ground between the PCM and A/C

compressor relay.

Is the action complete? — Verify repair —

50 Repair the short to ground between the A/C thermostat

relay and the electronic thermostat.

Is the action complete? — Verify repair —

Electronic Ignition System Diagnosis

If the engine cranks but will not run or immediately stalls,

the Engine Cranks But Will Not Start chart must be used

to determine if the failure is the ignition system or the fuel

system.

Visual Check of The Evaporative

Emission Canister

DIf the canister is cracked or damaged, replace the

canister.

DIf fuel is leaking from the canister, replace the canister

and check hoses and hose routing.

Fuel Metering System Check

Some failures of the fuel metering system will result in an

“Engine Cranks But Will Not Run” symptom. If this

condition exists, refer to the

Engine Cranks But Will Not

Run

chart. This chart will determine if the problem is

caused by the ignition system, the PCM, or the fuel pump

electrical circuit.

Refer to

Fuel System Electrical Test

for the fuel system

wiring schematic.

If there is a fuel delivery problem, refer to

Fuel System

Diagnosis

, which diagnoses the fuel injectors, the fuel

pressure regulator, and the fuel pump. If a malfunction

occurs in the fuel metering system, it usually results in

either a rich HO2S signal or a lean HO2S signal. This

condition is indicated by the HO2S voltage, which causes

the PCM to change the fuel calculation (fuel injector pulse

width) based on the HO2S reading. Changes made to the

fuel calculation will be indicated by a change in the long

term fuel trim values which can be monitored with a Tech

2. Ideal long term fuel trim values are around 0%; for a

lean HO2S signal, the PCM will add fuel, resulting in a fuel

trim value above 0%. Some variations in fuel trim values

are normal because all engines are not exactly the same.

If the evaporative emission canister purge is “ON,” the

long term fuel trim may be as low as –38%. If the fuel trim

values are greater than +23%, refer to

DTC P0131, DTC

P0151, DTC P0171, and DTC 1171

for items which can

cause a lean HO2S signal.

Idle Air Control (IAC) Valve

The Tech 2 displays the IAC pintle position in counts. A

count of “0” indicates the PCM is commanding the IAC

pintle to be driven all the way into a fully-seated position.

This is usually caused by a large vacuum leak.

The higher the number of counts, the more air is being

commanded to bypass the throttle blade. Refer to IAC

System Check in order to diagnose the IAC system.

Refer to

Rough, Unstable, or Incorrect Idle, Stalling

Symptoms

for other possible causes of idle problems.

Knock Sensor Diagnosis

The Tech 2 has two data displays available for diagnosing

the knock sensor (KS) system. The two displays are

described as follows:

D“Knock Retard” indicates the number of degrees that

the spark timing is being retarded due to a knock

condition.

D“KS Noise Channel” indicates the current voltage

level being monitored on the noise channel.

DTCs P0325 and P0327 are designed to diagnose the KS

module, the knock sensor, and the related wiring. The

problems encountered with the KS system should set a

DTC. However, if no DTC was set but the KS system is

suspect because of a detonation complaint, refer to

Detonation/Spark Knock

Symptoms

Powertrain Control Module (PCM)

Diagnosis

To read and clear diagnostic trouble codes, use a Tech 2.

IMPORTANT:Use of a Tech 2 is recommended to clear

diagnostic trouble codes from the PCM memory.

Diagnostic trouble codes can also be cleared by turning

the ignition “OFF” and disconnecting the battery power

from the PCM for 30 seconds. Turning off the ignition and

disconnecting the battery power from the PCM will cause

all diagnostic information in the PCM memory to be

cleared. Therefore, all the diagnostic tests will have to be

re-run.

Since the PCM can have a failure which may affect only

one circuit, following the diagnostic procedures in this

section will determine which circuit has a problem and

where it is.

If a diagnostic chart indicates that the PCM connections

or the PCM is the cause of a problem, and the PCM is

replaced, but this does not correct the problem, one of the

following may be the reason:

DThere is a problem with the PCM terminal

connections. The terminals may have to be removed

from the connector in order to check them properly.

DThe problem is intermittent. This means that the

problem is not present at the time the system is being

checked. In this case, refer to the

Symptoms

portion

of the manual and make a careful physical inspection

of all components and wiring associated with the

affected system.

DThere is a shorted solenoid, relay coil, or harness.

Solenoids and relays are turned “ON” and “OFF” by

the PCM using internal electronic switches called

drivers. A shorted solenoid, relay coil, or harness will

not damage the PCM but will cause the solenoid or

relay to be inoperative.

Multiple PCM Information Sensor

DTCS Set

Circuit Description

The powertrain control module (PCM) monitors various

sensors to determine the engine operating conditions.

The PCM controls fuel delivery, spark advance,

transmission operation, and emission control device

operation based on the sensor inputs.

The PCM provides a sensor ground to all of the sensors.

The PCM applies 5 volts through a pull-up resistor, and

determines the status of the following sensors by

monitoring the voltage present between the 5-volt supply

and the resistor:

DThe engine coolant temperature (ETC) sensor

DThe intake air temperature (IAT) sensor

DThe transmission fluid temperature (TFT) sensor

The PCM provides the following sensors with a 5-volt

reference and a sensor ground signal:

DThe exhaust gas recirculating (EGR) pintle position

sensor

DThe throttle position (TP) sensor

DThe manifold absolute pressure (MAP) sensor

The PCM monitors the separate feedback signals from

these sensors in order to determine their operating

status.

Diagnostic Aids

IMPORTANT:Be sure to inspect PCM and engine

grounds for being secure and clean.

A short to voltage in one of the sensor input circuits may

cause one or more of the following DTCs to be set:

DP0108

DP0113

DP0118

DP0123

DP0712

IMPORTANT:If a sensor input circuit has been shorted

to voltage, ensure that the sensor is not damaged. A

damaged sensor will continue to indicate a high or low

voltage after the affected circuit has been repaired. If the

sensor has been damaged, replace it.

An open in the sensor ground circuit between the PCM

and the splice will cause one or more of the following

DTCs to be set:

DP0108

DP0113

DP0118

DP0123

DP0712

A short to ground in the 5-volt reference A or B circuit will

cause one or more of the following DTCs to be set:

DP0107

DP0122

An the in the 5-volt reference circuit A, between the PCM

and the splice will cause one or more of the following

DTCs to be set:

DP0122

An the in the 5-volt reference circuit B, between the PCM

and the splice will cause one or more of the following

DTCs to be set:

DP0107

Check for the following conditions:

DPoor connection at PCM. Inspect the harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damage

terminals, and a poor terminal-to-wire connection.

DDamaged harness. Inspect the wiring harness for

damage. If the harness is not damaged, observe an

affected sensor’s displayed value on the Tech 2 with

the ignition “ON” and the engine “OFF” while you

move the connectors and the wiring harnesses

related to the following sensors:

DIAT

DECT

DTP

DMAP

DEGR

DTFT

Test Description

9. A faulty EGR valve can leak a small amount of

current from the ignition feed circuit to the 5-volt

reference A circuit. If the problem does not exist

with the EGR valve disconnected, replace the EGR

valve.

11-15. If a sensor input circuit has been shorted to

voltage, ensure that the sensor has not been

damaged. A damaged IAT or ECT sensor will

continue to indicate a high voltage or a low

temperature after the affected circuit has been

repaired. A dameged TP, MAP, fuel tank pressure,

or EGR pintle position sensor will indicate a high

voltage, a low voltage, or a fixed value after the

affected circuit has been repaired. If the sensor has

been damaged, replace it.

Multiple PCM Information Sensor DTCs Set

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Turn the ignition “OFF,” disconnect the PCM.

2. T urn the ignition “ON,” check the 5 volt reference A

circuit for the following conditions:

DA poor connection at the PCM.

DAn open between the PCM connector and the

splice.

DA short to ground.

DA short to voltage.

Is there an open or short? —Go to

Step 3

Go to

Step 4

3Repair the open or short.

Is the action complete? — Verify repair —

4Check the sensor ground circuit for the following

conditions:

DA poor connection at the PCM or the affected

sensors.

DAn open between the PCM connector and the

affected sensors.

Is there an open or a poor connection? —Go to

Step 5

Go to

Step 6

5Repair the open or the poor connection.

Is the action complete? — Verify repair —

6Measure the voltage between the EGR pintle position

sensor signal circuit at the PCM harness connector and

ground.

Does the voltage measure near the specified value? 0 V Go to

Step 7

Go to

Step 11

7Measure the voltage between the MAP sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to

Step 8

Go to

Step 14

8Measure the voltage between the TP sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to

Step 9

Go to

Step 15

9Measure the voltage between the IAT sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to

Step 10

Go to

Step 16

10 Measure the voltage between the ECT sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to

Step 11

Go to

Step 17

11 1. Disconnect the EGR valve.

2. Measure the voltage between the EGR pintle

position sensor signal circuit at the PCM harness

connector and ground.

Does the voltage measure near the specified value? 0 V Go to

Step 13

Go to

Step 18

12 Measure the voltage between the TFT sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to

Step 20

Go to

Step 19

Step NoYesValue(s)Action

13 Replace the EGR valve.

Is the action complete? — Verify repair —

14 Locate and repair the short to voltage in the MAP

sensor signal circuit.

Is the action complete? — Verify repair —

15 Locate and repair the short to voltage in the TP sensor

signal circuit.

Is the action complete? — Verify repair —

16 Locate and repair the short to voltage in the IA T sensor

signal circuit.

Is the action complete? — Verify repair —

17 Locate and repair the short to voltage in the ECT

sensor signal circuit.

Is the action complete? — Verify repair —

18 Locate and repair the short to voltage in the EGR pintle

position sensor signal circuit.

Is the action complete? — Verify repair —

19 Locate and repair the short to voltage in the TFT sensor

signal circuit.

Is the action complete? — Verify repair —

20 Replace the PCM.

Is the action complete? —

Go to

OBD

System

Check

—

Exhaust Gas Recirculation (EGR)

Diagnosis

Pintle position error diagnosis is covered by DTC P0402,

P0404, P1404, P0405, P0406. If EGR diagnostic trouble

codes P0402, P0404, P1404, P0405, P0406 are

encountered, refer to the DTC charts.

Engine Tech 2 Data Definitions and

Ranges

A/C CLUTCH–Tech 2 Displays ON or OFF–

Indicates whether the PCM has commanded the A/C

clutch ON. Used in A/C system diagnostic.

A/C REQUEST — Tech 2 Displays YES or NO —

Indicates the state of the A/C request input circuit from the

HVAC controls. The PCM uses the A/C request signal to

determine whether A/C compressor operation is being

requested.

AIR/FUEL RATIO — Tech 2 Range 0.0-25.5 —

Air/fuel ratio indicates the PCM commanded value. In

closed loop, the air/fuel ratio should normally be

displayed around “14.2–14.7.” A lower air/fuel ratio

indicates a richer commanded mixture, which may be

seen during power enrichment or TWC protection modes.

A higher air/fuel ratio indicates a leaner commanded

mixture. This can be seen during deceleration fuel mode.

BARO kPa — Tech 2 Range 10-105 kPa/0.00-5.00

Volts —

The barometric pressure reading is determined from the

MAP sensor signal monitored during key up and wide

open throttle (WOT) conditions. The barometric pressure

is used to compensate for altitude differences and is

normally displayed around “61-104” depending on

altitude and barometric pressure.

CHECK TRANS LAMP–AUTO TRANSMISSION–

Indicates the need to check for a DTC with the Tech 2

when the lamp is flashing 0.2 seconds ON and 0.2

seconds OFF.

CMP ACT. COUNTER –Cam Position

ActivityDECEL FUEL MODE—Tech 2 Display

ACTIVE or INACTVE—

“ACTIVE” displayed indicates that the PCM has detected

conditions appropriate to operate in deceleration fuel

mode. The PCM will command the deceleration fuel

mode when it detects a closed throttle position while the

vehicle is traveling over 20 mph. While in the decreasing

fuel mode, the PCM will decrease the amount of fuel

delivered by entering open loop and decreasing the

injector pulse width.

DESIRED EGR POS.—Tech 2 Range 0%-100%—

Represents the EGR pintle position that the PCM is

commanding.

DESIRED IDLE — Tech 2 Range 0-3187 RPM —

The idle speed that the PCM is commanding. The PCM

will compensate for various engine loads based on engine

coolant temperature, to keep the engine at the desired

speed.

ECT — (Engine Coolant Temperature) Tech 2

Range –40°C to 151°C (–40°F to 304°F) —

The engine coolant temperature (ECT) is mounted in the

coolant stream and sends engine temperature

information to the PCM. The PCM applies 5 volts to the

ECT sensor circuit. The sensor is a thermistor which

changes internal resistance as temperature changes.

When the sensor is cold (high resistance), the PCM

monitors a high signal voltage and interprets that as a cold

engine. As the sensor warms (decreasing resistance),

the voltage signal will decrease and the PCM will interpret

the lower voltage as a warm engine.

EGR DUTY CYCLE — Tech 2 Range 0%-100% —

Represents the EGR valve driver PWM signal from the

PCM. A duty cycle of 0% indicates that no EGR flow is

being commanded; a 100% duty cycle indicates

maximum EGR flow commanded.

EGR FEEDBACK — Tech 2 Range 0.00-5.00 Volts —

Indicates the EGR pintle position sensor signal voltage

being monitored by the PCM. A low voltage indicates a

fully extended pintle (closed valve); a voltage near 5 volts

indicates a retracted pintle (open valve).

ENGINE LOAD — Tech 2 Range 0%-100% —

Engine load is calculated by the PCM from engine speed

and MAF sensor readings. Engine load should increase

with an increase in RPM or air flow.

ENGINE RUN TIME — Tech 2 Range

00:00:00-99:99:99 Hrs:Min:Sec —

Indicates the time elapsed since the engine was started.

If the engine is stopped, engine run time will be reset to

00:00:00.

ENGINE SPEED — Range 0-9999 RPM —

Engine speed is computed by the PCM from the 58X

reference input. It should remain close to desired idle

under various engine loads with engine idling.

EVAP PURGE PWM — Tech 2 Range 0%-100% —

Represents the PCM commanded PWM duty cycle of the

EVAP purge solenoid valve. “0%” displayed indicates no

purge; “100%” displayed indicates full purge.

EVAP VENT VALVE– Tech 2 Displays PURGE or

NO PURGE–

The EV AP purge vacuum valve is a normally closed valve

positioned in the purge line between the canister and the

EVAP purge solenoid. The EVAP purge vacuum valve

will open when vacuum increases to greater than 5 inches

of water in the purge line. The EV AP purge vacuum valve

is used by the PCM to monitor EVAP canister purge

solenoid opetation and purge system integrity . The EVAP

purge vacuum valve should be closed to ground with no

vacuum present (0% EVAP purge PWM). With EVAP

purge PWM at 25% or greater, the EVAP purge vacuum

valve should be open and “PURGE” should be indicated.

FUEL TRIM CELL — Tech 2 Range 0-21 —

The fuel trim cell is dependent upon engine speed and

MAF sensor readings. A plot of RPM vs. MAF is divided

into 22 cells. Fuel trim cell indicates which cell is currently

active.

FUEL TRIM LEARN — Tech 2 Displays NO or YES

—

When conditions are appropriate for enabling long term

fuel trim corrections, fuel trim learn will display “YES.”

This indicates that the long term fuel trim is responding to

the short term fuel trim. If the fuel trim learn displays

“NO,” then long term fuel trim will not respond to changes

in short term fuel trim.

HO2S BANK 1, SEN. 1–Tech 2 Range 0-1132 mV–

Represents the fuel control exhaust oxygen sensor

output voltage. Should fluctuate constantly within a range

between 10 mV (lean exhaust) and 1000 mV (rich

exhaust) while operating in closed loop.

HO2S BANK2, SEN. 1—Tech 2 Range 0–1132 mV—

Represents the fuel control exhaust oxygen sensor

output voltage. Should fluctuate constantly within a range

between 10mV (lean exhaust) and 1000 mV (rich

exhaust) while operating in closed loop.

HO2S BANK 1, SEN. 1–Tech 2 Displays READY

YES/NO–

Indicates the status of the exhaust oxygen sensor. The

Tech 2 will indicate that the exhaust oxygen sensor is

ready when the PCM detects a fluctuating HO2S voltage

sufficient to allow closed loop operation. This will not

occur unless the exhaust oxygen sensor is warmed up.

HO2S BANK 2, SEN. 1–Tech 2 Displays READY

YES/NO–

Indicates the status of the exhaust oxygen sensor. The

Tech 2 will indicate that the exhaust oxygen sensor is

ready when the PCM detects a fluctuating HO2S voltage

sufficient to allow closed loop operation. This will not

occur unless the exhaust oxygen sensor is warmed up.

IAC POSITION — Tech 2 Range 0-255 Counts —

Displays the commanded position of the idle air control

pintle in counts. A larger number of counts means that

more air is being commanded through the idle air

passage. Idle air control should respond fairly quickly to

changes in engine load to maintain desired idle RPM.

IAT (INTAKE AIR TEMPERATURE)— Tech 2 Range

–40°C to 151°C (–40°F to 304°F) —

The PCM converts the resistance of the intake air

temperature sensor to degrees. Intake air temperature

(IA T) is used by the PCM to adjust fuel delivery and spark

timing according to incoming air density.

IGNITION 1 — Tech 2 Range 0-25.5 Volts —

This represents the system voltage measured by the

PCM at its ignition feed.

INJ. PULSE BANK 1/INJ. PULSE BANK 2– Tech 2

Range 0-1000 msec. –

Indicates the amount of time the PCM is commanding

each injector “ON” during each engine cycle. A longer

injector pulse width will cause more fuel to be delivered.

Injector pulse width should increase with increased

engine load.

KS NOISE CHANNEL (Knock Sensor)–

Indicates the output from the KS noise channel. There is

always some electrical noise in an engine compartment

and to avoid mistaking this as engine knock, the output

from the knock sensor is compared to the output from the

noise channel. A knock condition is not set unless the

knock sensor output is greater than the noise channel

output.

LONG TERM FUEL TRIM BANK 1/BANK 2 –

The long term fuel trim is derived from the short term fuel

trim values and represents a long term correction of fuel

delivery for the bank in question. A value of 0% indicates

that fuel delivery requires no compensation to maintain

the PCM commanded air/fuel ratio. A negative value

significantly below 0% indicates that the fuel system is

rich and fuel delivery is being reduced (decreased injector

pulse width). A positive value significantly greater than

0% indicates that a lean condition exists and the PCM is

compensating by adding fuel (increased injector pulse

width). Because long term fuel trim tends to follow short

term fuel trim, a value in the negative range due to

canister purge at idle should not be considered unusual.

Fuel trim values at maximum authority may indicate an

excessively rich or lean system.

LOOP STATUS — Tech 2 Displays OPEN or

CLOSED —

“CLOSED” indicates that the PCM is controlling fuel

delivery according to oxygen sensor voltage. In “OPEN”

the PCM ignores the oxygen sensor voltage and bases

the amount of fuel to be delivered on TP sensor, engine

coolant, and MAF sensor inputs only.

MAF — Tech 2 Range 0.0-512 gm/s —

MAF (mass air flow) is the MAF input frequency

converted to grams of air per second. This indicates the

amount of air entering the engine.

MAP — Tech 2 Range 10-105 kPa (0.00-4.97 Volts)—

The manifold absolute pressure (MAP) sensor measures

the change in the intake manifold pressure from engine

load, EGR flow, and speed changes. As intake manifold

pressure increases, intake vacuum decreases, resulting

in a higher MAP sensor voltage and kPa reading. The

MAP sensor signal is used to monitor intake manifold

pressure changes during the EGR flow test, to update the

BARO reading, and as an enabling factor for several of

the diagnostics.

MIL — Tech 2 Displays ON or OFF —

Indicates the PCM commanded state of the malfunction

indicator lamp.

POWER ENRICHMENT — Tech 2 Displays ACTIVE

or INACTIVE —

“ACTIVE” displayed indicates that the PCM has detected

conditions appropriate to operate in power enrichment

mode. The PCM will command power enrichment mode

when a large increase in throttle position and load is

detected. While in power enrichment mode, the PCM will

increase the amount of fuel delivered by entering open

loop and increasing the injector pulse width. This is done

to prevent a possible sag or hesitation from occurring

during acceleration.

RICH/LEAN BANK 1/ BANK 2 — Tech 2 Displays

RICH or LEAN —

Indicates whether oxygen sensor voltage is above a 600

mV threshold voltage (“RICH”) or below a 3000 mV

threshold voltage (“LEAN”). Should change constantly

while in closed loop, indicating that the PCM is controlling

the air/fuel mixture properly.

SHORT TERM FT BANK1/BANK2–

Short term fuel trim to a bank represents a short term

correction to bank fuel delivery by the PCM in response

to the amount of time the bank fuel control oxygen sensor

voltage spends above or below the 450 mV threshold. If

the oxygen sensor voltage has mainly remained less than

450 mV, indicating a lean air/fuel mixture, short term fuel

trim will increase into the positive range above 0% and

the PCM will pass fuel. If the oxygen sensor voltage stays

mainly above the threshold, short term fuel trim will

decrease below 0% into the negative range while the

PCM reduces fuel delivery to compensate for the

indicated rich condition. Under certain conditions such as

extended idle and high ambient temperatures, canister

purge may cause short term fuel trim to read in the

negative range during normal operation. Fuel trim values

at maximum authority may indicate an excessively rich or

lean system.

SPARK — Tech 2 Range –64° to 64° —

Displays the amount of spark advance being commanded

by the PCM on the IC circuit.

START-UP ECT — Tech 2 Range –40°C to 151°C

(–40°F to 304°F) —

Indicates the engine coolant temperature at the time that

the vehicle was started. Used by the HO2S diagnostic to

determine if the last start-up was a cold start.

START-UP IAT — Tech 2 Range –40°C to 151°C

(–40°F to 304°F) —

Indicates the intake air temperature at the time that the

vehicle was started. Used by the HO2S diagnostic to

determine if the last start-up was a cold start.

TP — Tech 2 Range 0%-100% —

TP (throttle position) angle is computed by the PCM from

the TP sensor voltage. TP angle should display “0%” at

idle and “100%” at wide open throttle.

TP SENSOR — Tech 2 Range 0.00-5.00 Volts —

The voltage being monitored by the PCM on the TP

sensor signal circuit.

WEAK CYLINDER –Tech 2 Displays Cylinder

Number—

This indicates that the PCM has detected crankshaft

speed variations that indicate 2% or more cylinder firing

events are misfires.

Typical Scan Data Values

Use the Typical Scan Data Values Table only after the

On-Board Diagnostic System Check has been

completed, no DTC(s) were noted, and you have

determined that the on-board diagnostics are functioning

properly. Tech 2 values from a properly-running engine

may be used for comparison with the engine you are

diagnosing. The typical scan data values represent

values that would be seen on a normally-running engine.

NOTE:A Tech 2 that displays faulty data should not be

used, and the problem should be reported to the Tech 2

manufacturer. Use of a faulty Tech 2 can result in

misdiagnosis and unnecessary replacement of parts.

Only the parameters listed below are referred to in this

service manual for use in diagnosis. For further

information on using the Tech 2 to diagnose the PCM and

related sensors, refer to the applicable reference section

listed below. If all values are within the typical range

described below, refer to the

Symptoms

section for

diagnosis.

Test Conditions

Engine running, lower radiator hose hot, transmission in

park or neutral, closed loop, accessaries off, brake not

applied and air conditioning off.

3.5L V-6 Engine

Tech 2 Parameter Data List Units

Displayed Typical Data Values

(IDLE) Typical Data Values

(2500 RPM)

Engine Speed Engine RPM Within –50 to +100 of

“Desired Idle” Actul engine speed

Desired Idle Speed Engine RPM 750 800

Engine Coolant Temperature Engine °C or °F80 – 100

(176 – 212 °F) 80 – 100

(176 – 212 °F)

Start Up ECT (Engine Coolant

Temperature) Engine °C or °F — —

Intake Air Temperature Engine °C or °F0 – 100, depends on

underhood 0 – 80, depends on

underhood

Start Up IAT (Intake Air Temperature) Engine °C or °F — —

Manifold Absolute Pressure Engine kPa 23 – 40 19 – 32

Manifold Absolute Pressure Engine V0.65 – 1.32 0.46 – 1.10

Barometric Pressure Engine kPa 61 – 104 (depends pn

altitude and

barometric)

61 – 104 (depends pn

altitude and

barometric)

Throttle Position Engine % 0 3 – 5

Throttle Position Sensor Engine V0.35 – 0.39 0.55 – 0.59

Mass Air Flow Engine g/s 2.85 – 6.65 9.5 – 16.5

Air Fuel Ratio Engine Ratio:_to1 14.7:1 14.7:1

Injection Pulse Bank 1 Engine ms 2.0 – 4.0 2.5 – 4.0

Injection Pulse Bank 2 Engine ms 2.0 – 4.0 2.5 – 4.0

Spark Advance Engine °CA 15 – 22 34 – 44

EGR Duty Cycle Engine % 0 0

Desired EGR Position Engine % 0 0

EGR Normalized Engine % 0 0

EGR Feedback Engine V0.45 – 0.80 0.45 – 0.80

EGR Closed Pintle Position Engine Steps 20 – 40 20 – 40

Catalyst Protection Mode Engine Yes/No No No

Knock Sensor Noise Channel Engine V0.10 – 0.40 0.50 – 1.75

A/C Clutch Relay Engine On/Off Off —

A/C Request Engine Yes/No No —

Camshaft Activity Engine Counts 0 – 255 always

increasing 0 – 255 always

increasing

EVAP Purge Solenoid (Evaporative

Emission) Engine On/Off Off Off

Fuel Pump Engine On/Off On On

Idle Air Control Engine Steps — —

Transmission Check Light Engine On/Off Off Off

Park/Neutral Position Engine P-N/R-D-

3-2-L P-N P-N

TCC Engaged Engine Yes/No No No

Vehicle Speed Engine MPH or

km/h 0 0

Ignition Voltage Engine V12.8 – 14.1 12.8 – 14.1

Tech 2 Parameter Typical Data Values

(2500 RPM)

Typical Data Values

(IDLE)

Units

Displayed

Data List

Fuel system Status Engine Closed

Loop

/Open

Loop

Closed Loop Closed Loop

Power Enrichment Engine Yes/No No No

Engine Load Engine %2.0 – 5.5 8.0 – 16.0

Time From Start Engine _:_:_ _:_:_ _:_:_

Deceleration Fuel Cutoff Engine Inactive/A

ctive Inactive Inactive

Malfunction Indicator Lamp Engine On/Off Off Off

VIM solenoid (Variable Intake

Manifold) Engine On/Off On On

Tech 2 Parameter Data List Units

Displayed Typical Data Values

(IDLE) Typical Data Values

(2500 RPM)

Engine Speed O2

Sensor RPM Within -50 to +100 of

“Desired Idle” Actul engine speed

Desired Idle Speed O2

Sensor RPM 750 800

Engine Coolant Temperature O2

Sensor

°C or °F80 – 100

(176 – 212 °F) 80 – 100 (176 – 212

°F)

Start Up ECT (Engine Coolant

Temperature) O2

Sensor

°C or °F — —

Intake Air Temperature O2

Sensor

°C or °F0 – 100, depends on

underhood 0 – 80, depends on

underhood

Start Up IAT (Intake Air Temperature) O2

Sensor

°C or °F — —

Manifold Absolute Pressure O2

Sensor kPa 23 – 40 19 – 32

Barometric Pressure O2

Sensor kPa 61 – 104 (depends pn

altitude and

barometric)

61 – 104 (depends pn

altitude and

barometric)

Throttle Position O2

Sensor % 0 3 – 5

Throttle Position Sensor O2

Sensor V0.35 – 0.39 0.55 – 0.59

Mass Air Flow O2

Sensor g/s 2.85 – 6.65 9.5 – 16.5

Air Fuel Ratio O2

Sensor g/s 2.85 – 6.65 9.5 – 16.5

B1 S1 O2 Sensor (Bank 1 Sensor 1) O2

Sensor mV 50 – 950 always

changing quickly 50 – 950 always

changing quickly

B2 S1 O2 Sensor (Bank 2 Sensor 1) O2

Sensor mV 50 – 950 always

changing quickly 50 – 950 always

changing quickly

B1 O2S Ready (Bank 1) O2

Sensor Yes/No Yes Yes

B2 O2S Ready (Bank 2) O2

Sensor Yes/No Yes Yes

B1 S1 O2S Warm Up Time (Bank1

Sensor 1) O2

Sensor seconds 24 – 45 24 – 45

B2 S1 O2S Warm Up Time (Bank2

Sensor 1) O2

Sensor seconds 24 – 45 24 – 45

B1 Long Term Fuel Trim (Bank1) O2

Sensor % — —

B2 Long Term Fuel Trim (Bank2) O2

Sensor % — —

B1 Short Term Fuel Trim (Bank1) O2

Sensor % — —

B2 Short Term Fuel Trim (Bank2) O2

Sensor % — —

Fuel Trim Cell O2

Sensor Cell No. 20 2 or 6

Fuel Trim Learned O2

Sensor Yes/No Yes Yes

B1 S1 Status (Bank 1 Sensor 1) O2

Sensor Lich/Lean — —

Tech 2 Parameter Typical Data Values

(2500 RPM)

Typical Data Values

(IDLE)

Units

Displayed

Data List

B2 S1 Status (Bank 2 Sensor 1) O2

Sensor Lich/Lean — —

Engine Load O2

Sensor %2.0 – 5.5 8.0 – 16.0

No Malfunction Indicator Lamp (MIL)

D06RX134

Circuit Description

The “Check Engine” lamp (MIL) should always be

illuminated and steady with the ignition “ON” and the

engine stopped. Ignition feed voltage is supplied to the

MIL bulb through the meter fuse. The powertrain control

module (PCM) turns the MIL “ON” by grounding the MIL

driver circuit.

Diagnostic Aids

An intermittent MIL may be cased by a poor connection,

rubbed-through wire insulation, or a wire broken inside

the insulation. Check for the following items:

DInspect the PCM harness and connections for

improper mating, broken locks, improperly formed or

damaged terminals, poor terminal-to-wire

connection, and damaged harness.

DIf the engine runs OK, check for a faulty light bulb, an

open in the MIL driver circuit, or an open in the

instrument cluster ignition feed.

DIf the engine cranks but will not run, check for an open

PCM ignition or battery feed, or a poor PCM to engine

ground.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. A “No MIL” condition accompanied by a no-start

condition suggests a faulty PCM ignition feed or

battery feed circuit.

9. Using a test light connected to B+, probe each of the

PCM ground terminals to ensure that a good ground

is present. Refer to

PCM Terminal End View

for

terminal locations of the PCM ground circuits.

12.In this step, temporarily substitute a known good

relay for the PCM relay. The horn relay is nearby,

and it can be verified as “good” simply by honking

the horn. Replace the horn relay after completing

this step.

No Malfunction Indicator Lamp (MIL)

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Attempt to start the engine.

Does the engine start? —Go to

Step 3

Go to

Step 6

3Check the meter fuse for the instrument cluster ignition

feed circuit.

Is the fuse OK? —Go to

Step 4

Go to

Step 16

4Ignition “ON,” probe the ignition feed circuit at the

cluster connector with a test light to ground.

Is the test light “ON?” —Go to

Step 5

Go to

Step 13

51. Ignition “OFF.”

2. Disconnect the PCM.

3. Jumper the MIL driver circuit at the PCM connector

to ground.

4. Ignition “ON.”

Is the MIL “ON?” —Go to

Step 10

Go to

Step 11

6Check the PCM ignition feed and battery feed fuses (15

A engine fuse and 15 A PCM fuse).

Are both fuses OK? —Go to

Step 7

Go to

Step 15

71. Ignition “OFF.”

2. Disconnect the PCM.

3. Ignition “ON.”

4. Probe the ignition feed circuit at the PCM harness

connector with a test light to ground.

Is the test light “ON?” —Go to

Step 8

Go to

Step 12

8Probe the battery feed circuit at the PCM harness

connector with a test light to ground.

Is the test light “ON?” —Go to

Step 9

Go to

Step 14

9Check for a faulty PCM ground connection.

Was a problem found? — Verify repair Go to

Step 10

10 Check for damaged terminals at the PCM.

Was a problem found? — Verify repair Go to

Step 17

11 Check for an open MIL driver circuit between the PCM

and the MIL.

Was a problem found? — Verify repair Go to

Step 18

12 Substitute a known “good” relay for the PCM main

relay.

Was the malfunction fixed? — Verify repair Go to

Step 13

13 Repair the open in the ignition feed circuit.

Is the action complete? — Verify repair —

14 Locate and repair the open PCM battery feed circuit.

Is the action complete? — Verify repair —

Step NoYesValue(s)Action

15 Locate and repair the short to ground in the PCM

ignition feed circuit or PCM battery feed circuit.

Is the action complete? — Verify repair —

16 Locate and repair the short to ground in the ignition

feed circuit to the instrument cluster, and replace the

fuse.

Is the action complete? — Verify repair —

17 Replace the PCM.

Is the action complete? — Verify repair —

18 Check the MIL driver circuit for a poor connection at the

instrument panel connector.

Was a problem found? — Verify repair

Go to

Instrument

Panel

Electrical

Diagnosis

Malfunction Indicator Lamp (MIL) “ON” Steady

D06RX012

Circuit description

The “Check Engine” lamp (MIL) should always be

illuminated and steady with ignition “ON” and the engine

stopped. Ignition feed voltage is supplied directly to the

MIL indicator. The powertrain control module (PCM)

turns the MIL “ON” by grounding the MIl driver circuit.

The MIL should not remain “ON” with the engine running

and no DTC(s) set. A steady MIl with the engine running

and no DTC(s) suggests a short to ground in the MIl driver

circuit.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed–through wire insulation, or a wire broken inside

the insulation. Check for the following items:

DPoor connection or damaged harness – Inspect the

PCM harness and connectors for improper mating,

broken locks, improperly formed or damaged

terminals, poor terminal-to-wire connection, and

damaged harness.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. If the MIL does not remain “ON” when the PCM is

disconnected, the MIL driver wiring is not faulty.

3. If the MIL driver circuit is OK, the instrument panel

cluster is faulty.

Malfunction Indicator Lamp (MIL) “ON” Steady

Step Action Value(s) YesNo

1Was the “On-Board diagnostic (OBD) System Check”

performed? — Go to

Step 2

Go to

OBD

System

Check

21. Ignition “OFF,” disconnect PCM.

2. Ignition “ON,” observe the MIL (Service Engine

Soon lamp).

Is the MIL “ON?” —Go to

Step 3

Go to

Step 5

31. Ignition “OFF,” disconnect the instrument panel

cluster.

2. Check the MIL driver circuit between the PCM and

the instrument panel cluster for a short to ground.

3. If a problem is found, repair as necessary.

Was the MIL driver circuit shorted to ground? —

Go to

OBD

System

Check

Go to

Step 4

4Replace the instrument panel cluster.

Is the action complete? —

Go to

OBD

System

Check

—

51. Ignition “OFF,” reconnect the PCM.

2. Using the Tech 2 output controls function, select

MIL dash lamp control and command the MIL

“OFF.” (Refer to the miscellaneous test)

Did the MIL turn “OFF?” —

Go to

OBD

System

Check

Go to

Step 6

6Replace the PCM.

Is the action complete? —

Go to

OBD

System

Check

—

Engine Cranks But Will Not Run

D06RX145

060RY00303

Engine Cranks But Will Not Run

Circuit Description

The electronic Ignition system uses a coil-at-plug method

of spark distribution. In this type of ignition system, the

powertrain control module (PCM) triggers the correct

driver inside the ignition coil, which then triggers the

correct ignition coil based on the 58X signal received from

the crankshaft position sensor (CKP). The spark plug

connected to the coil fires when the ignition coil opens the

ground circuit for the coil’s primary circuit.

During crank, the PCM monitors the CKP 58X signal. The

CKP signal is used to determine which cylinder will fire

first. After the CKP 58X signal has been processed by the

PCM, it will command all six injectors to allow a priming

shot of fuel for all the cylinders. After the priming, the

injectors are left “OFF” during the next six 58X reference

pulses from the CKP. This allows each cylinder a chance

to use the fuel from the priming shot. During this waiting

period, a camshaft position (CMP) signal pulse will have

been received by the PCM. The CMP signal allows the

PCM to operate the injectors sequentially based on

camshaft position. If the camshaft position signal is not

present at start-up, the PCM will begin sequential fuel

delivery with a 1-in-6 chance that fuel delivery is correct.

The engine will run without a CMP signal, but will set a

DTC code.

Diagnostic Aids

An intermittent problem may be caused by a poor

connection, rubbed-through wire insulation or a wire

broken inside the insulation. Check for the following

items:

DPoor connection or damaged harness – Inspect the

PCM harness and connectors for improper mating,

broken locks, improperly formed or damaged

terminals, poor terminal-to-wore connection, and

damaged harness.

DFaulty engine coolant temperature sensor – Using a

Tech 2, compare engine coolant temperature with

intake air temperature on a completely cool engine.

Engine coolant temperature should be within 10°C of

intake air temperature. If not, replace the ECT

sensor.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

5. An obvious cause of low fuel pressure would be an

empty fuel tank.

6. The engine will easily start and run if a few injectors

are disabled. It is not necessary to test all injectors

at this time since this step is only a test to verify that

all of the injectors have not been disabled by fuel

contamination.

7. A blinking test light verifies that the PCM is

monitoring the 58X crankshaft reference signal and

is capable of activating the injectors. If there is an

open or shorted driver circuit, DTCs 201-206 and a

misfire DTC 301-306 should be set.

By using a spark tester, each ignition coil’s ability to

produce 25,000 volts is verified.

If there is an open or shorted driver circuit, DTCs

201-206 should be set. All six injector driver circuits

can be checked at one time without removing the

intake manifold if a 5–8840–2619–0 test light is

available. This is the alternative procedure:

DWith the ignition “OFF,” disconnect the gray

connector located at the rear of the air filter, attached

to a bracket on the purge canister.

DConnect test light J 39021-95 to the connector. Do

any of the light constantly illuminate or fail to blink

when the engine is cranked? If so, repair the short or

open circuit, or replace the PCM if indicated.

This procedure only tests the driver circuit as far as the

test connection, so step 31 is added to test the circuit all

the way to the injector.

Engine Cranks But Will Not Run

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Check the 15 A ignition coil fuse, the 15 A engine

device fuse, and the 15A PCM fuse.

Was a fuse blown? —Go to

Step 3

Go to

Step 4

3Check for a short to ground and replace the fuse.

Is the action complete? — Verify repair —

41. Ignition “OFF,” install a fuel pressure gauge at the

test fitting on the fuel supply line in the engine

compartment. (Use a shop cloth to absorb any fuel

leakage while making the connection.)

2. Ignition “ON,” observe the fuel pressure.

Is the fuel pressure within the specified values, and

does it hold steady? 285-375 kPa

(43-55 psi) Go to

Step 6

Go to

Step 5

5Is any fuel pressure indicated?

—

Go to

Fuel

System

Electrical Test

Go to

Fuel

System

Diagnosis

6Install an injector test light at the #2 cylinder injector

harness connector (or install 5-8840-2636-0 test light

to the the injector test connector).

Does the light blink when the engine is cranked? —Go to

Step 7

Go to

Step 23

7Install an injector test light at the #2 cylinder injector

harness connector.

Does the light blink when the engine is cranked? —Go to

Step 14

Go to

Step 18

81. Ignition “ON.”

2. While the coil connectors are disconnected, touch

each coil connector’s ignition feed terminal with a

grounded test light (the ignition feed wire is black

with orange tracer).

Did the test light illuminate? —Go to

Step 10

Go to

Step 9

9Repair the open ignition feed circuit.

Is the action complete? — Verify repair —

10 While the coil connectors are disconnected, touch

each connector’s secondary ground terminal with a

test light to B+. (The ground wires are black.)

Did the test light illuminate at each coil connector? —Go to

Step 12

Go to

Step 11

11 Repair the open secondary ground circuit.

Is the action complete? — Verify repair —

12 1. Test the fuel for contamination.

2. If a problem is found, clean the fuel system and

correct the contaminated fuel condition as

necessary. Replace the fuel filter and replace any

injectors that are not delivering fuel (see Injector

Balance Test).

Was a problem found? — Verify repair Go to

Step 13

Step NoYesValue(s)Action

13 1. Remove any ignition coil and install a spark tester at

the spark plug end of the coil.

2. Observe the tester while the engine is cranking.

Was a crisp, blue spark observed? Only one or two

sparks followed by no result is considered the same as

“No Spark.” —Go to

Step 15

Go to

Step 14

14 Replace the ignition coil, and return to Step 19 to test

the remaining coils.

Is the action complete? — Verify repair —

15 Repeat Step 19 for each coil. Remove only one coil at a

time, and reinstall each coil on its spark plug after

testing, but do not refasten coils with screws at this

time.

After all coils have passed the spark test, does the

engine start? —

Refasten all

coils with

their screws Go to

Step 16

16 1. Remove the spark plugs from all cylinders.

2. Visually inspect the spark plug electrodes.

3. Replace any spark plugs with loose or missing

electrodes or cracked insulators.

Did your inspection reveal any spark plugs exhibiting

excessive fouling? —

Correct the

fouling

condition Go to

Step 17

17 Refer to

Engine Mechanical Diagnosis

to diagnose the

following conditions:

DFaulty or incorrect camshaft drive belts

DLeaking or sticky valves or rings

DExcessive valve deposits

DLoose or worn rocker arms

DWeak valve springs

DIncorrect valve timing

DLeaking head gasket

Is the action complete? — Verify repair Go to

Step 19

18 Observe the “Engine Speed” data display on the scan

tool while cranking the engine.

Is the engine RPM indicated? (If the scan tool is

normally powered from the cigarette lighter socket, and

if the scan tool display goes blank while cranking the

engine, it will be necessary to power the scan tool

directly from the vehicle battery.) —Go to

Step 19

Go to

Step 28

19 1. Disconnect the 7-pin gray connector at the rear of

the air filter beneath the point where the air duct

attaches to the MAF sensor.

2. Ignition “ON.”

3. Using a test light connected to ground, probe the

ignition terminal at the PCM (female) side of the

7-pin connector.

Is the test light “ON?” —Go to

Step 20

Go to

Step 26

StepNoYesValue(s)Action

20 1.At the PCM (female) side of the connector

mentioned in step 25, connect a test light between

the ignition + terminal and one of the injector driver

circuits at the same connector.

2.Ignition “ON.”

3.Observe the test light, and repeat the test for each

injector driver circuit.

Did the test light stay on when checking any of the 6

injector driver circuits? —Go to

Step 21

Go to

Step 23

21 1.Ignition “OFF,” disconnect the PCM.

2.Ignition “ON,” observe the test light.

Is the test light “ON?” —Go to

Step 22

Go to

Step 27

22 Locate and repair the short to ground in the injector

driver circuit.

Is the action complete? —Verify repair —

23 1.Using the same test location as in step 26, connect

a test light between the ignition terminal and one of

the driver circuits.

2.Crank the engine and observe the test light.

3.Repeat for each injector driver circuit.

Did the light blink during the test for each circuit? —Go to

Step 25

Go to

Step 24

24 Check for an open injector driver circuit.

Was a problem found? —Verify repair Go to

Step 27

25 1.At the injector (male) side of the gray connector

mentioned in step 25, connect an ohmmeter

between the ignition pin and one of the driver circuit

pins.

2.Check for continuity in the circuit.

3.Repeat for each injector circuit. The readings

should be approximately equal to the specified

value for injector resistance.

Was a problem found? 12.5 ohms Verify repair Go to

Step 8

26 Repair the ignition feed circuit.

Is the action complete? —Verify repair —

27 Replace the PCM.

IMPORTANT:The replacement PCM must be

programmed. Refer to

UBS 98model year Immobilizer

Workshop Manual.

Is the action complete? — Verify repair —

28 1. Raise the vehicle and disconnect the CKP sensor

harness.

2. Ignition “ON.”

3. With a test light to ground, probe the harness

ignition feed terminal.

Did the light illuminate? —Go to

Step 30

Go to

Step 29

29 Check the ignition feed wire between the sensor and

the PCM for a short to ground or open circuit.

Is the action complete? — Verify repair —

Step NoYesValue(s)Action

30 1. Ignition “ON.”

2. At the CKP harness connector, connect a test light

between the ignition and ground terminals.

Did the light illuminate? —Go to

Step 32

Go to

Step 31

31 Check the sensor ground circuit for an open or short to

voltage.

Is the action complete? — Verify repair —

32 Check the signal circuit between the sensor and the

PCM for a short to ground, short to voltage, or an open.

Was a problem found? — Verify repair Go to

Step 33

33 Replace the CKP position sensor.

Is the action complete? — Verify repair Go to

Step 27

Fuel System Electrical Test

D06RX014

Circuit Description

When the ignition switch is first turned “ON,” the

powertrain control module (PCM) energizes the fuel

pump relay which applies power to the in-tank fuel pump.

The fuel pump relay will remain “ON” as long as the

engine is running or cranking and the PCM is receiving

58X crankshaft position pulses. If no 58X crankshaft

position pulses are present, the PCM de-energizes the

fuel pump relay within 2 seconds after the ignition is

turned “ON” or the engine is stopped.

The fuel pump delivers fuel to the fuel rail and injectors,

then to the fuel pressure regulator. The fuel pressure

regulator controls fuel pressure by allowing excess fuel to

be returned to the fuel tank. With the engine stopped and

ignition “ON,” the fuel pump can be turned “ON” by using a

command by the Tech 2.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation, or a wire broken inside

the insulation. Check for the following items:

DPoor connection or damaged harness – Inspect the

PCM harness and connectors for improper mating,

broken locks, improperly formed or damaged

terminals, poor terminal-to-wire connection, and

damaged harness.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. If the fuel pump is operating but incorrect pressure is

noted, the fuel pump wiring is OK and the “Fuel

System Pressure Test” chart should be used for

diagnosis.

CAUTION:To reduce the risk of fire and personal

injury:

DIt is necessary to relieve fuel system pressure

before connecting a fuel pressure gauge. Refer to

Fuel Pressure Relief Procedure, below.

DA small amount of fuel may be released when

disconnecting the fuel lines. Cover fuel line

fittings with a shop towel before disconnecting, to

catch any fuel that may leak out. Place the towel in

an approved container when the procedure is

completed.

Fuel Pressure Relief Procedure

1.Remove the fuel cap.

2.Remove the fuel pump relay from the underhood

relay center.

3.Start the engine and allow it to stall.

4.Crank the engine for an additional 3 seconds.

Fuel Gauge Installation

1.Remove the shoulder fitting cap.

2.Install fuel gauge 5-8840-0378-0 to the fuel feed line

located in front of and above the right side valve

cover.

3.Reinstall the fuel pump relay.

Fuel System Electrical Test

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Read the “Caution” above.

2. Relieve the fuel system pressure and install the fuel

pump pressure gauge to the test fitting.

3. Ignition SW is “ON”.

4. Use a Tech 2 to command the fuel pump “ON.”

(Refer to Miscellaneous Test)

Is there an immediate pressure build-up which

indicates the pump is running? —Go to

Step 3

Go to

Step 4

31. V erify that the pump is not running by removing the

fuel filler cap and listening.

2. Command the pump “ON” with the Tech 2.

Did the pump turn “OFF” after 2 seconds? —Test

completed Go to

Step 12

41. Ignition “OFF.”

2. Remove the fuel pump relay.

3. Using a test light connected to ground, probe the

battery feed to the relay.

Did the light illuminate? —Go to

Step 6

Go to

Step 5

5Repair short or open battery feed to fuel pump relay.

Is the action complete? — Verify repair —

61. Connect a test light between the two wires that

connect to the fuel pump relay pull-in coil.

2. Ignition “ON.”

Did the test light illuminate for 2 seconds and then turn

off? — Go to

Step 12

Go to

Step 7

71. With a test light connected to battery (–), probe the

fuel pump relay connector at the wire which runs

from the relay pull–in coil to the PCM.

2. Ignition “ON.”

Did the test light illuminate for 2 seconds and then turn

off? — Go to

Step 8

Go to

Step 9

8Locate and repair open in the fuel pump relay ground

circuit.

Is the action complete? — Verify repair —

Step NoYesValue(s)Action

9Check for short or open between the PCM and the fuel

pump relay.

Was a problem found? — Verify repair Go to

Step 10

10 1. Check the fuel pump relay circuit for a poor terminal

connection at the PCM.

2. If a problem is found, replace terminal as necessary.

Was a problem found? — Verify repair Go to

Step 11

11 Replace the PCM.

Is the action complete? — Verify repair —

12 1. Reconnect the fuel pump relay.

2. Disconnect the fuel pump electrical connector at the

fuel tank.

3. Using a test light connected to ground, probe the

fuel pump feed wire (harness side).

4. Command the fuel pump “ON” with a Tech 2.

Did the light illuminate for 2 seconds? —Go to

Step 15

Go to

Step 13

13 1. Substitute a known good realy for the fuel pump

realy.

2. Leave the test light connected as in step 12.

3. Command the fuel pump “ON” with the Tech 2.

4. After this test, re-connect the known good relay in

its proper location.

Did the test light illuminate for 2 seconds when the fuel

pump was commanded “ON?” —Go to

Step 17

Go to

Step 14

14 Check for a short circuit, blown fuse or open circuit

between the relay and the fule tank.

Is the action complete? — Verify repair —

15 1. With the fuel pump electrical connector at the fuel

tank disconnected, connect a test light between the

feed wire and the ground wire (harness side).

2. Command the fuel pump “ON” with a Tech 2.

Did the test light illuminate for 2 seconds? —Go to

Step 18

Go to

Step 16

16 Repair the open circuit in the fuel pump ground wire.

Is the action complete? — Verify repair —

17 Replace the fuel pump relay.

Is the action complete? — Verify repair —

18 Replace the fuel pump.

Is the action complete? — Verify repair —

Fuel System Diagnosis

140RW022

Legend

(1) Fuel Filler Cap

(2) Fuel Tank

(3) Rollover Valve

(4) Fuel Pump and Sender Assembly

(5) Fuel Filter

(6) Fuel Rail Right

(7) Right Bank

(8) Fuel Rail Left

(9) Left Bank

(10) Fuel Pressure Control Valve

(11) Common Chamber

(12) Duty Solenoid Valve

(13) Throttle Valve

(14) Canister

(15) Evap Shut Off Valve

Circuit Description

When the ignition switch is turned “ON,” the powertrain

control module (PCM) will turn “ON” the in-tank fuel

pump. The in-tank fuel pump will remain “ON” as long as

the engine is cranking or running and the PCM is receiving

58X crankshaft position pulses. If there are no 58X

crankshaft position pulses, the PCM will turn the in-tank

fuel pump “OFF” 2 seconds after the ignition switch is

turned “ON” or 2 seconds after the engine stops running.

The in-tank fuel pump is an electric pump within an

integral reservoir. The in-tank fuel pump supplies fuel

through an in-line fuel filter to the fuel rail assembly. The

fuel pump is designed to provide fuel at a pressure above

the pressure needed by the fuel injectors. A fuel pressure

regulator, attached to the fuel rail, keeps the fuel available

to the fuel injectors at a regulated pressure. Unused fuel

is returned to the fuel tank by a separate fuel return line.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Connect the fuel pressure gauge to the fuel feed line

as shown in the fuel system illustration. Wrap a

shop towel around the fuel pressure connection in

order to absorb any fuel leakage that may occur

when installing the fuel pressure gauge. With the

ignition switch “ON” and the fuel pump running, the

fuel pressure indicated by the fuel pressure gauge

should be 333-376 kPa (48-55 psi). This pressure

is controlled by the amount of pressure the spring

inside the fuel pressure regulator can provide.

3. A fuel system that cannot maintain a constant fuel

pressure has a leak in one or more of the following

areas:

DThe fuel pump check valve.

DThe fuel pump flex line.

DThe valve or valve seat within the fuel pressure

regulator.

DThe fuel injector(s).

4. Fuel pressure that drops off during acceleration,

cruise, or hard cornering may case a lean condition.

A lean condition can cause a loss of power, surging,

or misfire. A lean condition can be diagnosed using

a Tech 2. If an extremely lean condition occurs, the

oxygen sensor(s) will stop toggling. The oxygen

sensor output voltage(s) will drop below 500 mV.

Also, the fuel injector pulse width will increase.

IMPORTANT:Make sure the fuel system is not

operating in the “Fuel Cut-Off Mode.”

When the engine is at idle, the manifold pressure is

low (high vacuum). This low pressure (high vacuum)

is applied to the fuel pressure regulator diaphragm.The low pressure (high vacuum) will offset the

pressure being applied to the fuel pressure regulatordiaphragm by the spring inside the fuel pressure

regulator. When this happens, the result is lower fuel

pressure. The fuel pressure at idle will vary slightly asthe barometric pressure changes, but the fuel

pressure at idle should always be less than the fuel

pressure noted in step 2 with the engine “OFF.”

16.Check the spark plug associated with a particular

fuel injector for fouling or saturation in order to

determine if that particular fuel injector is leaking. If

checking the spark plug associated with a particularfuel injector for fouling or saturation does notdetermine that a particular fuel injector is leaking,use the following procedure:

DRemove the fuel rail, but leave the fuel lines andinjectors connected to the fuel rail. Refer to

Fuel Rail Assembly

On-Vehicle Service

DLift the fuel rail just enough to leave the fuel injectornozzles in the fuel injector ports.

CAUTION:In order to reduce the risk of fire and

personal injury that may result from fuel spraying on

the engine, verify that the fuel rail is positioned over

the fuel injector ports and verify that the fuel injector

retaining clips are intact.

DPressurize the fuel system by connecting a 10 amp

fused jumper between B+ and the fuel pump relay

connector.

DVisually and physically inspect the fuel injectornozzles for leaks.17.A rich condition may result from the fuel pressure

being above 376 kPa (55 psi). A rich condition may

cause a DTC P0132 or a DTC P0172 to set.Driveability conditions associated with rich

conditions can include hard starting (followed by

black smoke) and a strong sulfur smell in theexhaust.

20.This test determines if the high fuel pressure is dueto a restricted fuel return line or if the high fuelpressure is due to a faulty fuel pressure regulator.

21.A lean condition may result from fuel pressure

below 333 kPa (48 psi). A lean condition maycause a DTC P0131 or a DTC P0171 to set.

Driveability conditions associated with leanconditions can include hard starting (when theengine is cold ), hesitation, poor driveability, lack ofpower, surging , and misfiring.

22.Restricting the fuel return line causes the fuel

pressure to rise above the regulated fuel pressure.

Command the fuel pump “ON” with the Tech 2. Thefuel pressure should rise above 376 kPa (55 psi) asthe fuel return line becomes partially closed.

NOTE:Do not allow the fuel pressure to exceed 414 kPa(60 psi). Fuel pressure in excess of 414 kPa (60 psi) maydamage the fuel pressure regulator.

CAUTION:To reduce the risk of fire and personal

injury:

DIt is necessary to relieve fuel system pressure

before connecting a fuel pressure gauge. Refer to

Fuel Pressure Relief Procedure, below.

DA small amount of fuel may be released when

disconnecting the fuel lines. Cover fuel line

fittings with a shop towel before disconnecting, to

catch any fuel that may leak out. Place the towel in

an approved container when the procedure is

completed.

Fuel Pressure Relief Procedure

1.Remove the fuel cap.

2.Remove the fuel pump relay from the underhood

relay center.

3.Start the engine and allow it to stall.

4.Crank the engine for an additional 3 seconds.

Fuel Gauge Installation

1.Remove the shoulder fitting cap.

2.Install fuel gauge 5-8840-0378-0 to the fuel supply

line located in front of and above the right side valve

cover.

3.Reinstall the fuel pump relay.

Fuel System Diagnosis

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Turn the ignition “OFF.”

2. Turn the air conditioning system “OFF.”

3. Relieve fuel system pressure and install the fuel

pressure gauge.

4. Turn the ignition “ON.”

NOTE: The fuel pump will run for approximately 2

seconds. Use the Tech 2 to command the fuel pump

“ON”.

(Refer to Miscellaneous Test)

5. Observe the fuel pressure indicated by the fuel

pressure gauge with the fuel pump running.

Is the fuel pressure within the specified limits? 290-376 kPa

(42-55 psi) Go to

Step 3

Go to

Step 17

3NOTE: The fuel pressure will drop when the fuel pump

stops running, then it should stabilize and remain

constant.

Does the fuel pressure indicated by the fuel pressure

gauge remain constant? —Go to

Step 4

Go to

Step 12

41. When the vehicle is at normal operation

temperature, turn the ignition “ON” to build fuel

pressure and observe the measurement on the

gauge.

2. Start the engine and observe the fuel pressure

gauge.

Did the reading drop by the amount specified after the

engine was started? 21-105 kPa

(3-15 psi) Go to

Step 5

Go to

Step 9

5Is fuel pressure dropping off during acceleration,

cruise, or hard cornering? —Go to

Step 6

Check for

improper fuel

6Visually and physically inspect the following items for a

restriction:

DThe in-pipe fuel filter.

DThe fuel feed line.

Was a restriction found? — Verify repair Go to

Step 7

7Remove the fuel tank and visually and physically

inspect the following items:

DThe fuel pump strainer for a restriction.

DThe fuel line for a leak.

DVerify that the correct fuel pump is in the vehicle.

Was a problem found in any of these areas? — Verify repair Go to

Step 8

8Replace the fuel pump.

Is the action complete? — Verify repair —

91. Disconnect the vacuum hose from the fuel pressure

regulator.

2. With the engine idling, apply 12-14 inches of

vacuum to the fuel pressure regulator.

Does the fuel pressure indicated by the fuel pressure

gauge drop by the amount specified? 21-105 kPa

(3-15 psi) Go to

Step 10

Go to

Step 11

Step NoYesValue(s)Action

10 Locate and repair the loss of vacuum to the fuel

pressure regulator.

Is the action complete? — Verify repair —

11 Replace the fuel pressure regulator.

Is the action complete? — Verify repair —

12 1. Run the fuel pump with the Tech 2.

2. After pressure has built up, turn off the pump and

clamp the supply hose shut with suitable locking

pliers which will not damage the hose.

Does the fuel pressure indicated by the fuel pressure

gauge remain constant? —Go to

Step 13

Go to

Step 15

13 Visually inspect the fuel supply line and repair any

leaks.

Was a problem found? — Verify repair Go to

Step 14

14 Remove the fuel tank and inspect for leaky hose or

in-tank fuel line.

Was a problem found? — Verify repair Go to

Step 8

15 1. If the pliers are still clamped to the fuel supply hose,

remove the locking pliers.

2. With suitable locking pliers which will not damage

the hose, clamp the fuel return line to prevent fuel

from returning to the fuel tank.

3. Run the fuel pump with the Tech 2.

4. After pressure has built up, remove power to the

pump.

Does the fuel pressure indicated by the fuel pressure

gauge remain constant? —Go to

Step 11

Go to

Step 16

16 Locate and replace any leaking fuel injector(s).

Is the action complete? — Verify repair —

17 Is the fuel pressure indicated by the fuel pressure

gauge above the specified limit? 376 kPa (55

psi) Go to

Step 18

Go to

Step 21

18 1. Relieve the fuel pressure. Refer to the

Fuel

Pressure Relief.

2. Disconnect the fuel return line from the fuel rail.

3. Attach a length of flexible hose to the fuel rail return

outlet passage.

4. Place the open end of the flexible hose into an

approved gasoline container.

5. Run the fuel pump with the Tech 2.

6. Observe the fuel pressure indicated by the fuel

pressure gauge with the fuel pump running.

Is the fuel pressure within the specified limits? 290-376 kPa

(42-55 psi) Go to

Step 19

Go to

Step 20

19 Locate and correct the restriction in the fuel return line.

Is the action complete? — Verify repair —

20 Visually and physically inspect the fuel rail outlet

passages for a restriction.

Was a restriction found? — Verify repair Go to

Step 11

StepNoYesValue(s)Action

21 Is the fuel pressure indicated by the fuel pressure

gauge above the specified value? 0 kPa (0 psi) Go to

Step 22

Go to

Step 23

22 1.Command the fuel pump “ON” with the Tech 2.

2.Using suitable pliers which will not damage the fuel

hose, gradually apply pressure with the pliers to

pinch the flexible fuel return hose closed.

CAUTION:Do not let the fuel pressure exceed

the second specified value.

Does the fuel pressure indicated by the fuel pressure

gauge rise above the first specified value?

376 kPa (55

psi). 414 kPa

(60 psi). Go to

Step 11

Go to

Step 7

23 1. Command the fuel pump “ON” with the Tech 2.

2. Remove the fuel filler cap and listen for the sound of

the fuel pump running.

3. Turn the pump off.

Was the fuel pump running? —Go to

Step 7

Go to

Fuel

System

Electrical Test

Chart

Idle Air Control (IAC) System Check

Circuit Description

The powertrain control module (PCM) controls engine

idle speed with the idle air control (IAC) valve. To increase

idle speed, the PCM retracts the IAC valve pintle away

from its seat, allowing more air to bypass the throttle bore.

To decrease idle speed, it extends the IAC valve pintle

towards its seat, reducing bypass air flow. A Tech 2 will

read the PCM commands to the IAC valve in counts.

Higher counts indicate more air bypass (higher idle).

Lower counts indicate less air is allowed to bypass (lower

idle).

Diagnostic Aids

A slow, unstable, or fast idle may be caused by a non-IAC

system problem that cannot be overcome by the IAC

valve. Out of control range IAC Tech 2 counts will be

above 60 if idle is too low, and zero counts if idle is too

high. The following checks should be made to repair a

non-IAC system problem:

DVacuum leak (high idle) – If idle is too high, stop the

engine. Fully extend (low) IAC with the Tech–2. Start

the engine. If idle speed is above 800 RPM, locate

and correct the vacuum leak, including the PCV

system. Check for binding of the throttle blade or

linkage.

DLean heated oxygen sensor signal (high air/fuel ratio)

– The idle speed may be too high or too low. Engine

speed may vary up and down, and disconnecting the

IAC valve does not help. Diagnostic trouble codes

P0131, P0151, P0171, or P0174 may be set. Tech 2

oxygen (O2) voltage will be less than 100 mV (0.1 V).

Check for low regulated fuel pressure, water in fuel, or

a restricted injector.

DRich heated oxygen sensor signal (low air/fuel ratio) –

The idle speed will be too low. Tech 2 IAC counts will

usually be above 80. The system is obviously rich

and may exhibit black smoke in the exhaust.

Tech 2 O2 voltage will be fixed at about 750 mV (0.75

V). Check for high fuel pressure, or a leaking or

sticking injector. A silicon-contaminated heated

oxygen sensor will show an O2 voltage slow to

respond on the Tech 2.

DThrottle body – Remove the IAC valve and inspect the

bore for foreign material.

DIAC valve electrical connections – IAC valve

connections should be carefully checked for proper

contact.

DPCV valve – An incorrect or faulty PCV valve may

result in an incorrect idle speed. Refer to

Diagnosis,

Rough Idle, Stalling

. If intermittent poor driveability or

idle symptoms are resolved by disconnecting the

IAC, carefully recheck the connections and valve

terminal resistance, or replace the IAC.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

1. The Tech–2 is used to extend and retract the IAC

valve. Valve movement is verified by an engine

speed change. If no change in engine speed

occurs, the valve can be resettled when removed

from the throttle body.

2. This step checks the quality of the IAC movement in

step 1. Between 700 revolutions per minute (RPM)

and about 1500 RPM, the engine speed should

change smoothly with each flash of the tester light

in both extend and retract. If the IAC valve is

retracted beyond the control range (about 1500

RPM), it may take many flashes to extend the IAC

valve before engine speed will begin to drop. This

is normal on certain engines. Fully extending the

IAC may cause engine stall. This may be normal.

6. Steps 1 and 2 verified the proper IAC valve

operation. This step checks the IAC circuits. Each

lamp on the noid light should flash red and green

while the IAC valve is cycled. While the sequence

of color is not important, if either light is “OFF” or

does not flash red and green, check the circuits for

faults, beginning with poor terminal contacts.

Idle Air Control (IAC) System Check

Step Action Value(s) Yes No

11. Ignition “OFF.”

2. Connect the Tech–2.

3. Set the parking brake.

4. Block the wheels.

5. Turn the air conditioning “OFF.”

6. Idle the engine in Park (A/T) or Neutral (M/T).

7. Operate the IAC test.

8. The engine speed should decrease and increase as

the IAC is cycled.

Does the RPM change? —Go to

Step 2

Go to

Step 3

2RPM should change smoothly.

Does the RPM change within the range specified? 700-1500

RPM —Go to

Step 3

3Check the IAC passages.

Are the IAC passages OK? —Go to

Step 4

Go to

Step 5

4Clear any obstruction from the IAC passages.

Is the action complete? — Verify repair —

5Replace the IAC. Refer to

On-V ehicle Service, Idle Air

Control Valve.

Is the action complete? — Verify repair —

Knock Sensor (KS) System Check (Engine Knock, Poor Performance, or Poor

Economy)

D06RW035–1

Circuit Description

The knock sensor (KS) sends an AC voltage signal to the

powertrain control module (PCM). As the KS detects

engine knock, the signal to the PCM changes in amplitude

and frequency. The PCM retards timing if the engine

speed is over 900 RPM.

Diagnostic Aids

If the KS system checks OK, but detonation is the

complaint, refer to

Diagnosis, Detonation/Spark Knock.

Test Description

The numbers below refer to the step numbers on the

Diagnostic Chart.

9. The change in signal speed depends on how hard

the tapping is done. Normally there is about 1.5 to

10 mV at PCM pin A2 with the engine off. Loud

tapping should be able to make the reading jump to

20-25 mV AC.

Knock Sensor (KS) System Check (Engine Knock, Poor Performance, or Poor

Economy)

Step Action Value(s) Yes No

1Is DTC P0325 or P0327 set?

—

Go to

DTC

P0325 or

DTC P0327

Go to

Step 2

2Run the engine at 1500 RPM.

Is there an internal engine knock? —Go to

Step 3

Go to

Step 4

3Repair the mechanical problem.

Is the action complete? — Verify repair —

41. Install the Tech 2.

2. Turn the ignition “ON.”

3. On the Tech 2 select F0: Data List.

4. Cycle through the list until “Knock Noise Channel” is

displayed.

Is knock retard at the specified value? more than

0.1V Go to

Step 5

Go to

Step 6

5Replace the PCM.

Is the action complete? — Verify repair —

Step NoYesValue(s)Action

61. Start the engine.

2. Monitor the knock retard display on the Tech 2 while

changing the throttle setting to place different loads

on the engine.

Is knock retard at the specified value? (Turn the ignition

“OFF.”) 0°Go to

Step 9

Go to

Step 7

71. At the rear of the engine, behind the rear fuel

injector on the side, disconnect the 2-wire knock

sensor harness connector.

NOTE: The connector for the knock sensor cannot

easily be removal unless common chamber is

removed. (Knock Sensor is on Right side of block).

Also, there are two (2) shield grounded wires.

The connector only has one wire (Yellow). Please

use another method.

2. Attach the positive lead of DVM to B+.

3. On the main harness side of the connector , use the

negative lead of the DVM to probe the connector pin

that is connected to black wire.

Dose the DVM indicate the specified value?

(Reconnect the knock sensor harness.) B+ Go to

Step 9

Go to

Step 8

8Repair the open black wire ground for the shield which

prevents stray electromagnetic pulses from affecting

the knock signal.

Is the action complete? — Verify repair —

91. Reconnect the wire harness if it was previously

disconnected in Step 7.

2. Set a DVM to AC voltage.

3. With the DVM, backprobe the PCM connector at

A2.

4. Tap the engine lift bracket with a socket extension.

Did the DVM show an increase in AC voltage while

tapping on the lift bracket? —System OK Go to

Step 10

10 Replace the knock sensor.

Is the action complete? — Verify repair —

Exhaust Gas Recirculation (EGR) System Check

D06RW055

Circuit Description

A properly operation exhaust gas recirculation (EGR)

system will directly affect the air/fuel requirements of the

engine. Since the exhaust gas introduced into the air/fuel

mixture is an inert gas (contains very little or no oxygen),

less fuel is required to maintain a correct air/fuel ratio.

Introducing exhaust gas into the combustion chamber

lowers combustion temperatures and reduces the

formation of oxides of nitrogen (NOx) in the exhaust gas.

Lower combustion temperatures also prevent detonation.

If the EGR pintle were to stay closed, the inert exhaust

gas would be replaced with air and the air/fuel mixture

would be leaner. The powertrain control module (PCM)

would compensate for the lean condition by adding fuel,

resulting in higher long term fuel trim values.

Diagnostic Aids

The EGR valve chart is a check of the EGR system. An

EGR pintle constantly in the closed position could cause

detonation and high emissions of NOx. It could also result

in high long term fuel trim values in the open throttle cell,

but not in the closed throttle cell. An EGR pintle

constantly in the open position would cause a rough idle.

Also, an EGR mounted incorrectly (rotated 180°) could

cause rough idle. Check for the following items:

DEGR passages – Check for restricted or blocked EGR

passages.

DManifold absolute pressure sensor – A manifold

absolute pressure sensor may shift in calibration

enough to affect fuel delivery. Refer to

Manifold

Absolute Pressure Output Check.

Exhaust Gas Recirculation (EGR) System Check

Step Action Value(s) Yes No

1Check the EGR valve for looseness.

Is the EGR valve Loose? —Go to

Step 2

Go to

Step 3

2Tighten the EGR valve.

Is the action complete? — Verify repair —

31. Place the transmission selector in Park or Neutral.

2. Start the engine and idle until warm.

3. Using a T ech 2, command EGR “50% ON.” (Refer to

Miscellaneous Test)

Does the engine idle rough and lose RPMs? —

EGR system

working

properly. No

problem

found. Go to

Step 4

41. Engine “OFF.”

2. Ignition “ON.”

3. Using a test light to ground, check the EGR harness

between the EGR valve and the ignition feed.

Does the test light illuminate? —Go to

Step 6

Go to

Step 5

5Repair the EGR harness ignition feed.

Was the problem corrected? — Verify repair Go to

Step 6

61. Remove the EGR valve.

2. Visually and physically inspect the EGR valve

pintle, valve passages and adapter for excessive

deposits, obstructions or any restrictions.

Does the EGR valve have excessive deposits,

obstructions or any restrictions? —Go to

Step 7

Go to

Step 8

7Clean or replace EGR system components as

necessary.

Was the problem corrected? — Verify repair Go to

Step 8

81. Ground the EGR valve metal case to battery (–).

2. Using a Tech 2, command EGR “ON” and observe

the EGR valve pintle for movement.

Does the EGR valve pintle move according to

command? — Go to

Step 9

Go to

DTC

P1404 chart

91. Remove the EGR inlet and outlet pipes from the

intake and exhaust manifolds.

2. Visually and physically inspect manifold EGR ports

and EGR inlet and outlet pipes for blockage or

restriction caused by excessive deposits or other

damage.

Do the manifold EGR ports or inlet and outlet pipes

have excessive deposits, obstructions, or any

restrictions? — Go to

Step 10

EGR system

working

properly. No

problem

found.

10 Clean or replace EGR system components as

necessary.

Is the action complete? — Verify repair —

Manifold Absolute Pressure (MAP) Output Check

D06RX135

Circuit Description

The manifold absolute pressure (MAP) sensor measures

the changes in the intake MAP which result from engine

load (intake manifold vacuum) and engine speed

changes; and converts these into a voltage output. The

powertrain control module (PCM) sends a 5-volt

reference voltage to the MAP sensor. As the MAP

changes, the output voltage of the sensor also changes.

By monitoring the the sensor output voltage, the PCM

knows the MAP. A lower pressure (low voltage) output

voltage will be about 1-2 volts at idle. Higher pressure

(high voltage) output voltage will be about 4-4.8 volts at

wide open throttle. The MAP sensor is also used, under

certain conditions, to measure barometric pressure,

allowing the PCM to make adjustments for different

altitudes. The PCM uses the MAP sensor to diagnose

proper operation of the EGR system, in addition to other

functions.

Test Description

IMPORTANT:Be sure to used the same diagnostic test

equipment for all measurements.

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

1. Applying 34 kPa (10 Hg) vacuum to the MAP sensor

should cause the voltage to be 1.5-2.1 volts less

than the voltage at step 1. Upon applying vacuum

to the sensor, the change in voltage should be

instantaneous. A slow voltage change indicates a

faulty sensor.

IMPORTANT:Make sure the electrical connector

remains securely fastened.

2. Disconnect the sensor from the bracket. Twist the

sensor with your hand to check for an intermittent

connection. Output changes greater than 0.10 volt

indicate a bad sensor.

Manifold Absolute Pressure (MAP) Output Check

Step Action Value(s) Yes No

11. Turn the ignition “OFF” and leave it “OFF” for 15

seconds.

2. Ignition “ON.” Don’t crank engine.

3. The Tech 2 should indicate a manifold absolute

pressure (MAP) sensor voltage.

4. Compare this scan reading to scan reading of a

known good vehicle obtained using the exact same

procedure as in Steps 1–4.

Is the voltage reading the same +/–0.40 volt? —Go to

Step 2

Go to

Step 5

21. Disconnect the MAP sensor and plug inletmanifold.

2. Connect a hand vacuum pump to the MAP sensor.

3. Start the engine.

4. Apply 34 kPa (10 Hg) of vacuum and note the

voltage change.

Is the voltage change 1.5-2.1 volts less than step 1? —Go to

Step 3

Go to

Step 4

3Check the sensor cover for leakage or restriction.

Does the cover supply vacuum to the MAP sensor

only? — Go to

Step 5

Go to

Step 4

4Repair the material to block.

Is the action complete? — Verify repair —

5Check the sensor connection.

Is the sensor connection good? —Go to

Step 5

Go to

Step 6

6Refer to

On-Vehicle Service, MAP Sensor .

Is the action complete? — Verify repair —

7Repair the poor connection.

Is the action complete? — Verify repair —

Evaporative (EVAP) Emissions Canister Purge Valve Check

D06RX016

Circuit Description

The evaporative emissions canister purge is controlled by

a solenoid that allows manifold and/or vacuum to purge

the canister when it is energized. The powertrain control

module (PCM) supplies a ground to energize the solenoid

valve (purge “ON”). The EVAP purge solenoid control is

turned “ON” and “OFF” several times a second. The duty

cycle (pulse width or “ON” time) is determined by engine

operating conditions including load, throttle position,

coolant temperature and ambient temperature. The duty

cycle is calculated by the PCM and the purge solenoid is

enabled when the appropriate conditions have been met:

DThe engine run time after start is more than 60

seconds.

DThe engine coolant temperature is above 30°C

(86°F).

DThe fuel control system is operating in the closed-loop

mode.

Diagnostic Aids

DMake a visual check of vacuum hoses.

DCheck the throttle body for possible cracked.

DCheck the malfunction indicator lamp for a possible

mechanical problem.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

1. Check to see if the solenoid is open or closed. The

solenoid is normally de-energized in this step, so it

should be closed.

2. This step checks to determine if the solenoid was

open due to an electrical circuit problem or a

defective solenoid.

3. This should normally energize the solenoid, opening

the valve and allowing the vacuum to drop (purge

“ON”).

Evaporative (EVAP) Emissions Canister Purge Valve Check

Step Action Value(s) Yes No

11. Ignition “OFF.”

2. Ignition “ON,” engine “OFF.”

3. At the throttle body, disconnect the hose that goes

to the pump solenoid.

4. Using a hand vacuum pump with an attached

vacuum gauge 5-8840-0279-0, apply vacuum (10”

Hg or 34 kPa) to the solenoid.

Does the solenoid hold the vacuum? —Go to

Step 3

Go to

Step 2

21. Disconnect the solenoid electrical connector.

2. As in Step 1, apply vacuum (10” Hg or 34 kPa) to the

solenoid.

Does the solenoid hold the vacuum? —Go to

Step 4

Go to

Step 7

31. At the throttle body, put a cap over the vacuum port

where the hose was disconnected for testing. This

is to prevent a vacuum leak when the engine is

started.

2. Ignition “OFF.”

3. Install the Tech 2.

4. Apply vacuum to the purge solenoid with the hand

vacuum pump.

5. Start the engine, run at 2500 RPM.

6. Using the Tech 2, select F0: Engine, F3: Misc.

Tests, F0: EVAP Purge.

7. Turn the purge solenoid “ON.”

Did the vacuum drop when the purge was turned on? —Go to

Step 8

Go to

Step 9

4Check for a short to ground in the RED/BLU wire.

Is there a short? —Go to

Step 5

Go to

Step 6

5Repair the short to ground.

Is the action complete? — Verify repair —

6Replace the PCM.

Is the action complete? — Verify repair —

7Replace the faulty purge solenoid. Refer to

On-Vehicle

Service, EVAP Canister Purge Solenoid.

Is the action complete? — Verify repair —

81. Turn the ignition “OFF.”

2. At the throttle body, install a vacuum gauge where

the hose from the purge solenoid was disconnected

for testing.

3. Start the engine.

4. Stabilize the engine speed at about 2500 RPM.

5. Momentarily snap the throttle open and let it return

to idle.

Is there approximately 10” Hg (34 kPa) of vacuum

available at the EVAP emission canister purge

solenoid? —

No problem

found in the

EVAP

emission

canister

purge valve

check

Refer to

Diagnostic

Aids

Step NoYesValue(s)Action

91. Disconnect the solenoid electrical connector.

2. Connect a test lamp between the harness

terminals.

Does the test lamp light? —Go to

Step 7

Go to

Step 10

10 Probe terminal A and terminal B with a test lamp to

ground.

Does the test lamp light on both terminals? —Go to

Step 11

Go to

Step 12

11 Repair the short to voltage in the RED/BLUE wire.

Is the action complete? — Verify repair —

12 Does on of the terminals light the test lamp? —Go to

Step 13

Go to

Step 14

13 Check for an open in the RED/BLU wire between the

purge solenoid and the PCM.

Was there an open circuit? —Go to

Step 15

Go to

Step 6

14 Repair the open in the BLK/YEL wire.

Is the action complete? — Verify repair —

15 Repair the open in the RED/BLU wire.

Is the action complete? — Verify repair —

PCM Diagnostic Trouble Codes

The following table lists the diagnostic trouble codes

supported by this vehicle application.If any DTCs not

listed here are displayed by a T ech 2, the Tech 2 data may

be faulty; notify the Tech 2 manufacturer of any DTCs

displayed that are not included in the following table.

PCM Diagnostic Trouble Codes

DTC Description Type Illuminate MIL

P0101 MAF System Performance BYes

P0102 MAF Sensor Circuit Low Frequency AYes

P0103 MAF Sensor Circuit High Frequency AYes

P0107 MAP Sensor Circuit Low Voltage AYes

P0108 MAP Sensor Circuit High Voltage AYes

P0112 IAT Sensor Circuit Low Voltage AYes

P0113 IAT Sensor Circuit High Voltage AYes

P0117 ECT Sensor Circuit Low Voltage AYes

P0118 ECT Sensor Circuit High Voltage AYes

P0121 TP System Performance AYes

P0122 TP Sensor Circuit Low Voltage AYes

P0123 TP Sensor Circuit High Voltage AYes

P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1 AYes

P0132 HO2S Circuit High Voltage Bank 1 Sensor 1 AYes

P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1 AYes

P0151 HO2S Circuit Low Voltage Bank 2 Sensor 1 AYes

P0152 HO2S Circuit High Voltage Bank 2 Sensor 1 AYes

P0154 HO2S Circuit Insufficient Activity Bank 2 Sensor 1 AYes

P0171 Fuel Trim System Lean Bank 1 BYes

P0172 Fuel Trim System Rich Bank 1 BYes

P0174 Fuel Trim System Lean Bank 2 BYes

P0175 Fuel Trim System Rich Bank 2 BYes

P0201 Injector 1 Control Circuit AYes

P0202 Injector 2 Control Circuit AYes

P0203 Injector 3 Control Circuit AYes

P0204 Injector 4 Control Circuit AYes

P0205 Injector 5 Control Circuit AYes

P0206 Injector 6 Control Circuit AYes

P0325 KS Module Circuit B No

P0327 KS Sensor Circuit B No

P0336 58X Reference Signal Circuit BYes

P0337 CKP Sensor Circuit Low Frequency BYes

P0341 CMP Sensor Circuit Performance BYes

P0342 CMP Sensor Circuit Low BYes

P0351 Ignition 1 Control Circuit AYes

P0352 Ignition 2 Control Circuit AYes

P0353 Ignition 3 Control Circuit AYes

P0354 Ignition 4 Control Circuit AYes

DTC Description Type Illuminate MIL

P0355 Ignition 5 Control Circuit AYes

P0356 Ignition 6 Control Circuit AYes

P0404 EGR Open Stuck BYes

P0405 EGR Lo Volt AYes

P0406 EGR Hi Voltage AYes

P0502 VSS Circuit Low Input BYes

P0562 System Voltage Low D No

P0563 System Voltage High D No

P0601 PCM Memory AYes

P0705 Transmisson Rang Sensor Illegal Position (Refer to

4L30-E Automatic

Transmission

)D No

P0706 Transmisson Range Sensor Performance (Refer to

4L30-E Automatic

Transmission

)D No

P0712 Transmission Fluid Temperature (TFT) Low Voltage (Refer to

4L30-E

Automatic Transmission Diagnosis

)D No

P0713 Transmission Fluid Temperature (TFT) High Voltage (Refer to

4L30-E

Automatic Transmission Diagnosis

)D No

P0719 Brake Switch Circuit Low (

Refer to 4L30-E Automatic Transmission

Diagnosis

)D No

P0722 Output Speed Sensor Circuit No Signal (Refer to

4L30-E Automatic

Transmission

)AYes

P0723 Output Speed Sensor Circuit Intermittent Signal (Refer to

4L30-E

Automatic Transmission

)AYes

P0730 Incorrect Gear Ratio (Refer to

4L30-E Automatic Transmission

) C No

P0748 Transmission Pressure Control Solenoid (PCS) – Electrical Circuit Fault

(Refer to

4L30-E Automatic Transmission Diagnosis

)C No

P0753 Transmission Shift Solenoid “A” – Electrical Circuit Fault (Refer to

4L30-E

Automatic Transmission Diagnosis

)AYes

P0758 Transmission Shift Solenoid “B” – Electrical Circuit Fault (Refer to

4L30-E

Automatic Transmission Diagnosis

)AYes

P1171 Fuel System Lean During Acceleration AYes

P1380 ABS Rough Road ABS System Fault DYes

P1381 ABS Rough Class 2 Serial Link Error DYes

P1404 EGR Closed Stuck DYes

P1508 IAC System Low RPM BYes

P1509 IAC System High RPM BYes

P1618 Serial Peripheral Interface (SPI) PCM Interprocessor Communication

Error (Automatic Transmission Only) AYes

P1625 PCM Unexpected Reset AYes

P1640 Driver-1-Input High Voltage D No

P1790 TRANS ROM Checksum Error (Refer to

4L30-E Automatic Transmission

Diagnosis

)AYes

P1792 TRANS EEPROM Checksum Error (Refer to

4L30-E Automatic

Transmission Diagnosis

)AYes

P1835 TRANS Kick Down Switch Malfunction (Refer to

4L30-E Automatic

Transmission Diagnosis

)D No

DTC Description Type Illuminate MIL

P1850 Brake Band Apply Solenoid Manlfunction (Refer to

4L30-E Automatic

Transmission Diagnosis

)D No

P1860 TCC PWM Solenoid Circuit Fault (Refer to

4L30-E Automatic

Transmission Diagnosis

)AYes

Diagnostic Trouble Code (DTC) P0101 MAF System Performance

D06RW057

Circuit Description

The mass air flow (MAF) sensor measures the amount of

air which passes through it into the engine during a given

time. The powertrain control module (PCM) uses the

mass air flow information to monitor engine operating

conditions for fuel delivery calculations. A large quantity

of air entering the engine indicates an acceleration or high

load situation, while a small quantity or air indicates

deceleration or idle.

The MAF sensor produces a frequency signal which can

be monitored using a Tech 2. The frequency will vary

within a range of around 4 to 7 g/s at idle to around 25 to 40

g/s at maximum engine load. DTC P0101 will be set if the

signal from the MAF sensor does not match a predicted

value based on throttle position and engine RPM.

Conditions for Setting the DTC

DThe engine is running.

DNo TP sensor or MAP sensor DTCs are set.

DThe throttle is steady, TP angle doesn’t change by

more than 1%.

DSystem voltage is between 11.5 volts and 16 volts.

DCalculated air flow is between 25 g/second and 40

g/second.

DAbove conditions present for at least 1 second.

DMAF signal frequency indicates an airflow significantly

higher or lower than a predicted value based on throttle

position and engine RPM for a total of 12.5 seconds

over a 25-second period of time.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM calculates an airflow value based on idle air

control valve position, throttle position, RPM and

barometric pressure.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0101 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0101 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by the following:

DPoor connections.

DMis-routed harness.

DRubbed through wire insulation.

DBroken wire inside the insulation.

Refer to Intermittents under service category Symptoms.

Any un-metered air may cause this DTC to set. Check for

the following:

DThe duct work at the MAF sensor for leaks.

DAn engine vacuum leak.

DThe PCV system for vacuum leaks.

DAn incorrect PCV valve.

DThe engine oil dip stick not fully seated.

DThe engine oil fill cap loose or missing.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. The MAF system performance or “rationality”

diagnostic uses the MAP sensor signal along with

other input to calculate an expected airflow rate that

is then compared to the actual measured airflow

from the MAF sensor. The first few steps of this

table verify that the MAP sensor is working properly.

6. Verifies the signal circuit from the MAF sensor

electrical connector to the PCM.

Verifies whether a ground and B+ circuit is

available.

DTC P0101 – MAF System Performance

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “OFF.”

2. Disconnect the Mass Air Flow (MAF) Sensor

harness connector from the MAF Sensor.

3. Place an unpowered test lamp between the 12 volt

signal circuit and the ground circuit, both at the MAF

Sensor connector.

4. Ignition “ON,” Engine“OFF.”

Did the test lamp illuminate? —Go to

Step 6

Go to

Step 3

31. Ignition “ON,” Engine “OFF.”

2. Using a Digital Voltmeter (DVM), check the 12 volt

signal circuit for the correct voltage.

Did the DVM indicate a value within the following

range? 11.5 to 12.5

Volt Go to

Step 5

Go to

Step 4

41. Ignition “OFF.”

2. Check the 12 volt signal circuit for the following

conditions:

DAn open circuit

DA short to ground

Was the problem found? — Verify repair —

5Check the MAF ground circuit for the following

conditions:

DAn open circuit

DA short to voltage

Was a problem found? — Verify repair —

61. Ignition “OFF.”

2. Check the MAF Sensor signal circuit between the

PCM and the MAF Sensor for the following

conditions:

DAn open circuit

DA short to ground

DA short to battery voltage

Was a problem found? — Verify repair Go to

Step 7

Step NoYesValue(s)Action

71. Connect the MAF Sensor wiring harness connector

to the MAF Sensor.

2. Connect the Tech 2 to the vehicle.

3. Place the Transmission in Park/Neutral, and fully

apply the Parking Brake.

4. Start the engine.

5. Select the Mass Air Flow (MAF) parameter on the

Tech 2.

With the engine idling, does the Tech 2 display the

following value(s)? 4 to 7 g/s Go to

Step 8

Go to

Step 9

8Observe the Tech 2 value while increasing the engine

RPM to its upper limit.

Does the Tech 2 display the following value(s)? 25 to 40 g/s Go to

Step 10

Go to

Step 9

9Replace the MAF Sensor.

Is the action complete? — Verify repair —

10 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0102 MAF Sensor Circuit Low Frequency

D06RW057

Circuit Description

The mass air flow (MAF) sensor measures the amount of

air which passes through it into the engine during a given

time. The powertrain control module (PCM) uses the

mass air flow information to monitor engine operating

conditions for fuel delivery calculations. A large quantity

of air entering the engine indicates an acceleration or high

load situation, while a small quantity of air indicates

deceleration or idle.

The MAF sensor produces a frequency signal which can

be monitored using a Tech 2. The frequency will vary

within a range of around 4 to 7 g/s at idle to around 1900

Hz at maximum engine load. DTC P0102 will be set if the

signal from the MAF sensor is below the possible range of

a normally operating MAF sensor.

Conditions for Setting the DTC

DThe engine is running above 500 RPM for greater than

10 seconds.

DSystem voltage is above 11.5 volts.

DMAF signal frequency is below 1.6 g/s for a total of

50-percent of the last 1000 samples monitored. A

sample is taken every cylinder event.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM calculates an air flow value based on idle air

control valve position, throttle position, RPM and

barometric pressure.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0102 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0102 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DMisrouted harness – Inspect the MAF sensor harness

to ensure that it is not routed too close to high voltage

wires.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Tech 2 while moving connectors and wiring harnesses

related to the MAF sensor . A change in the display will

indicate the location of the fault.

DPlugged intake air duct or filter element – A wide-open

throttle acceleration from a stop should cause the

mass air flow displayed on a Tech 2 to increase from

about 3-6 g/second at idle to 100 g/second or greater

at the time of the 1-2 shift. If not, check for a restriction.

If DTC P0102 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. This step verifies that the problem is present at idle.

4. A voltage reading of less than 4 or over 5 volts at the

MAF sensor signal circuit indicates a fault in the

wiring or a poor connection.

5. This verifies that ignition feed voltage and a good

ground are available at the MAF sensor.

DTC P0102 – MAF Sensor Circuit Low Frequency

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Start the engine.

2. With the engine idling, monitor “MAF Frequency”

display on the Tech 2.

Is the “MAF Frequency” below the specified value? 2.85 – 6.65

g/s Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0102.

Does the Tech 2 indicate DTC P0102 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect the MAF sensor connector.

3. Ignition “ON,” engine “OFF.”

4. Using a DVM, measure voltage between the MAF

sensor signal circuit and battery ground.

Is the voltage near the specified value? 5 V Go to

Step 5

Go to

Step 8

5Connect a test light between the MAF sensor ignition

feed and ground circuits at the MAF sensor harness

connector.

Is the test light “ON?” —Go to

Step 13

Go to

Step 6

6Connect a test light between the MAF sensor ignition

feed circuit and battery ground.

Is the test light “ON?” —Go to

Step 12

Go to

Step 7

71. Check for a poor connection at the MAF sensor.

2. If a poor connection is found, replace the faulty

terminal(s).

Was a poor connection found? — Verify repair Go to

Step 11

81. Ignition “OFF.”

2. Disconnect the MAF sensor.

3. Disconnect the PCM connector for the MAF signal

circuit.

4. Ignition “ON,” engine “OFF.”

5. With the DVM, measure the voltage between the

MAF signal terminal at the PCM and battery ground.

Is the voltage under the specified value? 4 V Go to

Step 9

Go to

Step 10

Step NoYesValue(s)Action

91. Ignition “OFF.”

2. Disconnect the PCM white connector.

3. Ignition “ON.”

4. Check the MAF sensor signal circuit for a short to 5

volts.

Is the action complete? — Verify repair —

10 1. Ignition “OFF.”

2. Disconnect the PCM white connector.

3. Ignition “ON.”

4. Check the MAF sensor signal circuit between the

PCM and the MAF sensor for an open, short to

ground, or short to the MAF ground circuit.

Is the action complete? — Verify repair Go to

Step 13

11 Locate and repair the open in the ground circuit to the

MAF sensor.

Is the action complete? — Verify repair —

12 Locate and repair the open in the ignition feed circuit to

the MAF sensor.

Is the action complete? — Verify repair —

13 Replace the MAF sensor.

Is the action complete? — Verify repair Go to

Step 14

14 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0103 MAF Sensor Circuit High Frequency

D06RW057

Circuit Description

The mass air flow (MAF) sensor measures the amount of

air which passes through it into the engine during a given

time. The powertrain control module (PCM) uses the

mass air flow information to monitor engine operating

conditions for fuel delivery calculations. A large quantity

of air entering the engine indicates an acceleration or high

load situation, while a small quantity of air indicates

deceleration or idle.

The MAF sensor produces a frequency signal which can

be monitored using a Tech 2. The frequency will vary

within a range of around 4 to 7 g/s at idle to around 9000

Hz at maximum engine load. DTC P0103 will be set if the

signal from the MAF sensor is above the possible range of

a normally operating MAF sensor.

Conditions for Setting the DTC

DThe engine is running above 500 RPM for more than

10 seconds.

DSystem voltage is above 11.5 volts.

DMAF signal frequency is above 40 g/s for a total of 50

percent of the last 200 samples monitored. A sample

is taken every cylinder event.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM calculates an airflow value based on idle air

control valve position, throttle position, RPM and

barometric pressure.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0103 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0103 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

If DTC P0103 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. This step verifies that the problem is present at idle.

4. A frequency reading with the MAF sensor connector

disconnected indicates an electromagnetic

interference (EMI) related fault.

DTC P0103 – MAF Sensor Circuit High Frequency

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0103.

Does the Tech 2 indicate DTC P0103 failed this

ignition? — Go to

Step 3

Refer to

Diagnostic

Aids

31. Start the engine.

2. With the engine idling, monitor “MAF Frequency”

display on the Tech 2.

Is “MAF Frequency” above the specified value? 40 g/s Go to

Step 4

Go to

Step 7

41. Ignition “OFF.”

2. Disconnect the MAF sensor connector.

3. Ignition “ON,” engine idling.

4. Using a Tech 2, monitor “MAF Frequency.”

Does the Tech 2 indicate a “MAF Frequency” at the

specified value? 0 g/s Go to

Step 5

Go to

Step 6

5Replace the MAF sensor.

Is the action complete? — Verify repair Go to

Step 8

61. Check the MAF harness for incorrect routing near

high voltage components (solenoids, relays,

motors).

2. If incorrect routing is found, correct the harness

routing.

Was a problem found? — Verify repair Go to

Step 6

71. With the engine idling, monitor “MAF Frequency”

display on the Tech 2.

2. Quickly snap open throttle to wide open throttle

while under a road load and record value.

Does the Tech 2 indicate “MAF Frequency” above the

specified value? 40 g/s Go to

Step 5

Go to

Step 8

8Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0107 MAP Sensor Circuit Low Voltage

D06RX135

Circuit Description

The manifold absolute pressure (MAP) sensor responds

to changes in intake manifold pressure (vacuum). The

MAP sensor signal voltage to the powertrain control

module (PCM) varies from below 2 volts at idle (high

vacuum) to above 4 volts with the ignition “ON,” engine

not running or at wide-open throttle (low vacuum).

The MAP sensor is used to determine manifold pressure.

The PCM monitors the MAP signals for voltages outside

the normal range of the MAP sensor. If the PCM detects a

MAP signal voltage that is excessively low, DTC P0107

will be set.

Conditions for Setting the DTC

DNo TP sensor DTCs present.

DEngine is running.

DThrottle angle is above 1% if engine speed is less than

1000 RPM.

DThrottle angle is above 2% if engine speed is above

1000 RPM.

DThe MAP sensor indicates manifold absolute pressure

at or below 11 kPa for a total of approximately 10

seconds over a 16-second period.

DIgnition voltage more than 11 volts.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will default to a BARO value of 79.3 kPa.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0107 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0107 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DCheck for intermittent codes.

DThe MAP sensor shares a ground with the Fuel Tank

Pressure Sensor, the ECT sensor, and the

Transmission Fluid Temperature sensor.

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

MAP display on the Tech 2 while moving connectors

and wiring harnesses related to the sensor . A change

in the display will indicate the location of the fault.

If DTC P0107 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

If it is determined that the DTC occurs intermittently,

performing the DTC P0107 Diagnostic Chart may isolate

the cause of the fault.

DThe MAP sensor shares a 5 Volt Reference with the

Fuel pressure sensor. If these codes are also set, it

could indicate a problem with the 5 Volt reference

circuit.

DThe MAP sensor shares a ground with the Fuel

pressure Sensor, the ECT sensor, and the

Transmission Fluid Temperature sensor.

DTC P0107 – MAP Sensor Circuit Low Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. With the throttle closed, observe the MAP value

displayed on the Tech 2.

Is the MAP value near the specified value? 11 kPa at sea

level Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0107.

Does the Tech 2 indicate DTC P0107 failed? —Go to

Step 4

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect the MAP sensor electrical connector.

3. Jumper the 5 volt reference “A” circuit and the MAP

signal together at the MAP sensor harness

connector.

4. Ignition “ON.”

5. Observe the MAP value displayed on the Tech 2.

Is the MAP value near the specified value? (if no, start

with the diagnosis chart for other sensors in the circuit

and see if 5V returns.) 5 V 104 kPa Go to

Step 10

Go to

Step 5

51. Disconnect the jumper.

2. Connect a test light between B+ and the MAP

sensor signal circuit at the MAP sensor harness

connector.

3. Observe the MAP value displayed on the Tech 2.

Is the MAP value near the specified value. 5 V 104 kPa Go to

Step 6

Go to

Step 8

61. Ignition “OFF.”

2. Disconnect the PCM and check the 5 volt reference

“A” circuit for an open or short to ground.

3. If the 5 volt reference “A” circuit is open or shorted to

ground, repair it as necessary.

Was the 5 volt reference “A” circuit open or shorted to

ground? — Verify repair Go to

Step 7

7Check the 5 volt reference “A” circuit for a poor

connection at the PCM and replace the terminal if

necessary.

Did the terminal require replacement? — Verify repair Go to

Step 11

Step NoYesValue(s)Action

81. Ignition “OFF.”

2. Disconnect the PCM, and check the MAP signal

circuit for an open, short to ground, or short to the

sensor ground circuit.

3. If the MAP sensor signal circuit is open or shorted to

ground, repair it as necessary.

W as the MAP signal circuit open or shorted to ground? —Verify repair Go to

Step 9

9Check the MAP sensor signal circuit for a poor

connection at the PCM and the MAP sensor; replace

the terminal if necessary.

Did the terminal require replacement? — Verify repair Go to

Step 11

10 Replace the MAP sensor.

Is the action complete? — Verify repair —

11 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0108 MAP Sensor Circuit Hight Voltage

D06RX135

Circuit Description

The manifold absolute pressure (MAP) sensor responds

to changes in intake manifold pressure (vacuum). The

MAP sensor signal voltage to the powertrain control

module (PCM) varies from below 2 volts at idle (high

vacuum) to above 4 volts with the key “ON,” engine not

running or at wide- open throttle (low vacuum).

The PCM monitors the MAP signals for voltages outside

the normal range of the MAP sensor. If the PCM detects a

MAP signal voltage that is excessively high, DTC P0108

will be set.

Conditions for Setting the DTC

DNo TP sensor DTCs present.

DEngine is running for more than 10 seconds.

DThrottle position is below 3% if engine speed is below

1000 RPM.

DThrottle position is below 10% if engine speed is above

1000 RPM.

DThe MAP sensor indicates an intermittent manifold

absolute pressure above 80 kPa for a total of

approximately 10 seconds over a 16-second period.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will default to a BARO value of 79.3 kPa.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0108 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0108 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

MAP display on the Tech 2 while moving connectors

and wiring harnesses related to the sensor . A change

in the display will indicate the location of the fault.

If DTC P0108 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set. If

it is determined that the DTC occurs intermittently,

performing the DTC P1108 Diagnostic Chart may isolate

the cause of the fault.

DThe MAP sensor shares a 5 Volt Reference with the

Fuel pressure sensor. If these codes are also set, it

could indicate a problem with the 5 Volt reference

circuit.

DThe MAP sensor shares a ground with the Fuel

pressure Sensor, the ECT sensor, and the

Transmission Fluid Temperature sensor.

DTC P0108 – MAP Sensor Circuit High Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. If the engine idle is rough, unstable or incorrect,

repair the idle problem before using this chart. Refer

Symptoms

section.

2. With the engine idling, note the MAP value on the

Tech 2.

Is the MAP reading above the specified value? 90 kPa Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0108.

Does the Tech 2 indicate DTC P0108 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect the MAP sensor electrical connector.

3. Ignition “ON.”

4. Note the MAP sensor voltage displayed on the T ech

Is the MAP sensor voltage at the specified value? (If no,

start with diagnostic chart for other sensors in the

circuit and see if 5 V returns) 0.0 V 11 kPa Go to

Step 5

Go to

Step 6

5Probe the sensor ground circuit with a test light to B+.

Is the test light “ON?” —Go to

Step 7

Go to

Step 9

61. Check the MAP signal circuit for a short to voltage or

a short to the 5 volt reference “A” circuit.

2. If the MAP sensor signal circuit is shorted, repair

circuit as necessary.

Was the MAP sensor signal circuit shorted? — Verify repair Go to

Step 11

71. Check for a poor sensor ground terminal connection

at the MAP sensor electrical connector.

2. If a problem if found, replace the faulty terminal.

Did the terminal require replacement? — Verify repair Go to

Step 8

8Check for a plugged or leaking vacuum supply to the

MAP sensor.

Is the vacuum supply plugged or leaking? — Verify repair Go to

Step 12

91. Check for a poor sensor ground terminal connection

at the PCM.

2. If a problem is found, replace the faulty terminal.

Did the terminal require replacement? — Verify repair Go to

Step 10

Step NoYesValue(s)Action

10 1. Check the continuity of the MAP sensor ground

circuit.

2. If the MAP sensor ground circuit measures over 5

ohms, repair open or poor connection.

Was a condition found and corrected? — Verify repair Go to

Step 11

11 Replace the PCM.

Is the action complete? —Verify Repair —

12 Replace the MAP sensor.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0112 IAT Sensor Circuit Low Voltage

D06RW078

Circuit Description

The intake air temperature (IAT) sensor is a thermistor

which measures the temperature of the air entering the

engine. The powertrain control module (PCM) applies 5

volts through a pull-up resistor to the IAT sensor. When

the intake air is cold, the sensor resistance is high and the

PCM will monitor a high signal voltage on the IAT signal

circuit. If the intake air is warm, the sensor resistance is

lower , causing the PCM to monitor a lower voltage. DTC

P0112 will set when the PCM detects an excessively low

signal voltage on the intake air temperature sensor signal

circuit.

Conditions for Setting the DTC

DThe engine has been running for over 2 minutes.

DVehicle speed is greater than 30 mph (48 km/h) .

DIAT signal voltage indicates an intake air temperature

greater than 148°C (298°F) (about 5 volts) for a total

of 12.5 seconds over a 25-second period of time.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0112 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0112 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

IA T display on the T ech 2 while moving connectors and

wiring harnesses related to the IAT sensor. A change

in the IAT display will indicate the location of the fault.

If DTC P0112 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart:

2. Verifies that the fault is present.

3. If DTC P0112 can be repeated only by duplicating

the Failure Records condition, refer to the

Temperature vs. Resistance Value

table. The table

may be used to test the IAT sensor at various

temperatures to evaluate the possibility of a

“shifted” sensor that may be stored above or below

a certain temperature. If this is the case, replace

the IAT sensor. If the IAT sensor appears to be OK,

the fault is intermittent; refer to

Diagnostic Aids

Intake Air Temperature Sensor

°C°F OHMS

Temperature vs. Resistance Values (approximate)

100 212 177

80 176 332

60 140 667

45 113 1188

35 95 1802

25 77 2796

15 59 4450

5 41 7280

–5 23 12300

–15 5 21450

–30 –22 52700

–40 –40 100700

DTC P0112 – IAT Sensor Circuit Low Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Using a Tech 2, monitor the intake air temperature

(IAT).

Is the intake air temperature greater than the specified

value? 148°C

(283°F) Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.” Review and record

Tech 2 Failure Records data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor the “DTC” info for DTC

P0112.

Does the Tech 2 indicate DTC P0112 failed this

ignition? —Refer to

Test

Description

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect the IAT sensor electrical connector.

3. Ignition “ON.”

4. Observe the intake air temperature on the Tech 2.

Is the intake air temperature below the specified value? –38°C

(–36°F) Go to

Step 6

Go to

Step 5

51. Ignition “OFF.”

2. Disconnect the PCM electrical connectors.

3. Check the IAT sensor signal circuit for a short to

ground.

Is the IAT sensor signal circuit shorted to ground? — Verify repair Go to

Step 7

6Replace the IAT sensor.

Is the action complete? — Verify repair —

7Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0113 IAT Sensor Circuit High Voltage

D06RW078

Circuit Description

The intake air temperature (IAT) sensor is a thermistor

which measures the temperature of the air entering the

engine. The powertrain control module (PCM) applies 5

volts through a pull-up resistor to the IAT sensor. When

the intake air is cold, the sensor resistance is high and the

PCM will monitor a high signal voltage on the IAT signal

circuit. If the intake air is warm, the sensor resistance is

lower causing the PCM to monitor a lower voltage. DTC

P01 13 will set when the PCM detects an excessively high

signal voltage on the intake air temperature sensor signal

circuit.

Conditions for Setting the DTC

DThe engine has been running for over 4 minutes.

DVehicle speed is less than 20 mph (32 km/h).

DECT signal temperature is above 60°C (140°F).

DMass air flow is less then 20 g/second.

DIAT signal voltage indicates an intake air temperature

less than –39°C (–38°F) for total of 12.5 seconds over

a 25-second period.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0113 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0113 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

IA T display on the T ech 2 while moving connectors and

wiring harnesses related to the IAT sensor. A change

in the IAT display will indicate the location of the fault.

If DTC P0113 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart:

2. Verifies that the fault is present.

3. If DTC P0113 can be repeated only by duplicating

the Failure Records conditions, refer to the

“Temperature vs. Resistance Values” table. The

table may be used to test the IAT sensor at various

temperatures to evaluate the possibility of a

“shifted” sensor that may be open above or below a

certain temperature. If this is the case, replace the

IAT sensor. If the IAT sensor appears to be OK, the

fault is intermittent; refer to

Diagnostic Aids

Intake Air Temperature Sensor

°C°F OHMS

Temperature vs. Resistance Values (approximate)

100 212 177

80 176 332

60 140 667

45 113 1188

35 95 1802

25 77 2796

15 59 4450

5 41 7280

–5 23 12300

–15 5 21450

–30 –22 52700

–40 –40 100700

DTC P0113 –IAT Sensor Circuit High Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Ignition “ON,” engine “OFF.” Observe the “Intake Air

Temp” display on the Tech 2.

Is the “Intake Air Temp” below the specified value? –38°C

(–36°F) Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data

parameters.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0113.

Does the Tech 2 indicate DTC P0113 failed? —Refer to

Test

Description

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect the IAT sensor electrical connector.

3. Jumper the IA T signal circuit and the sensor ground

circuit together at the IAT sensor harness

connector.

4. Ignition “ON.”

5. Observe the “Intake Air Temp” display on the Tech

Is the “Intake Air Temp” at the specified value? 140°C

(284°F) Go to

Step 6

Go to

Step 5

51. Jumper the IAT signal circuit at the IAT sensor

harness connector to chassis ground.

2. Observe the “Intake Air Temp” display on the Tech

Is the “Intake Air Temp” at the specified value? 140°C

(284°F) Go to

Step 7

Go to

Step 8

6Check for poor connections at the IAT sensor and

replace terminals if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 10

71. Ignition “OFF.”

2. Disconnect the PCM, and check the IAT sensor

ground circuit for an open.

3. If the IAT sensor ground circuit is open, repair it as

necessary.

Was the IAT sensor ground circuit open? — Verify repair Go to

Step 9

81. Ignition “OFF.”

2. Disconnect the PCM, and check the IAT signal

circuit for an open.

3. If the IAT sensor signal circuit is open, repair it as

necessary.

Was the IAT signal circuit open? — Verify repair Go to

Step 9

9Check for a poor sensor ground or IAT signal circuit

terminal connection at the PCM and replace

terminal(s) if necessary.

Did any of the terminals need to be replaced? — Verify repair Go to

Step 11

Step NoYesValue(s)Action

10 Replace the IAT sensor.

Is the action complete? — Verify repair —

11 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0117 ECT Sensor Circuit Low Voltage

060RY00304

Circuit Description

The engine coolant temperature (ECT) sensor is a

thermistor mounted on a coolant crossover pipe at the

front of the engine. The powertrain control module (PCM)

applies a voltage (about 5 volts) through a pull-up resistor

to the ECT signal circuit. When the engine coolant is cold,

the sensor (thermistor) resistance is high, therefore the

PCM will measure a high signal voltage. As the engine

coolant warms, the sensor resistance becomes lower,

and the ECT signal voltage measured at the PCM drops.

With a fully warmed-up engine, the ECT signal voltage

should measure about 1.5 to 2.0 volts.

Conditions for Setting the DTC

DEngine running time is longer than one minute.

DThe ECT sensor signal indicates an engine coolant

temperature greater than 150°C (302°F) (about 0.10

V) for a total of 50 seconds over a 100-second period.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will substitute the ECT reading with a default

engine coolant temperature value. The default value

is based on start-up intake air temperature and running

time.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0117 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0117 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

ECT display on the Tech 2 while moving connectors

and wiring harnesses related to the ECT sensor. A

change in the ECT display will indicate the location of

the fault.

If DTC P0117 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Verifies that the fault is present.

3. If DTC P0117 can be repeated only by duplicating

the Failure Records conditions, refer to the

“Temperature vs. Resistance Values” table. The

table may be used to test the ECT sensor at various

temperatures to evaluate the possibility of a

“shifted” sensor that may be shorted above or below

a certain temperature. If this is the case, replace

the ECT sensor. If the ECT sensor appears to be

OK, the fault is intermittent; refer to

Diagnostic Aids

Engine Coolant Temperature Sensor

°C°F OHMS

Temperature vs. Resistance Values (approximate)

100 212 177

80 176 332

60 140 667

45 1131188

35 95 1802

25 77 2796

15 59 4450

5 41 7280

–5 23 12300

–15 5 21450

–30 –22 52700

–40 –40 100700

DTC P0117 – ECT Sensor Low Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Observe the “Eng Cool T emp” display on the T ech 2.

Is the “Eng Cool Temp” below the specified value? 139°C

(282°F) Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0117.

Does the Tech 2 indicate DTC P0117 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

41. Disconnect the ECT sensor electrical connector.

2. Observe the “Eng Cool T emp” display on the T ech 2.

Is the “Eng Cool Temp” at the specified value? –39°C

(–38°F) Go to

Step 6

Go to

Step 5

51. Ignition “OFF.”

2. Disconnect the PCM and check the ECT signal

circuit for a short to ground or a short to the sensor

ground circuit.

3. If the ECT signal circuit is shorted. repair it as

necessary.

Was the ECT signal circuit shorted to ground? — Verify repair Go to

Step 7

6Replace the ECT sensor.

Is the action complete? — Verify repair —

7Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0118 ECT Sensor Circuit High Voltage

060RY00304

Circuit Description

The engine coolant temperature (ECT) sensor is a

thermistor mounted in on a coolant crossover pipe at the

front of the engine. The powertrain control module (PCM)

applies a voltage (about 5 volts) through a pull-up resistor

to the ECT signal circuit. When the engine coolant is cold,

the sensor (thermistor) resistance is high, therefore the

PCM will measure a high signal voltage. As the engine

coolant warms, the sensor resistance becomes less, and

the ECT signal voltage measured at the PCM drops. With

a fully warmed-up engine, the ECT signal voltage should

measure about 1.5 to 2.0 volts.

Conditions for Setting the DTC

DEngine running time is longer than 1.5 minutes.

DThe ECT sensor signal indicates an engine coolant

temperature of –39°C (–38°F) or less (about 5 volts)

for a total of 50 seconds over a 100-second period.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will substitute the ECT reading with a default

engine coolant temperature value. The default value

is based on start-up intake air temperature and running

time.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0118 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0118 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

ECT display on the Tech 2 while moving connectors

and wiring harnesses related to the ECT sensor. A

change in the ECT display will indicate the location of

the fault.

If DTC P0118 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Verifies that the fault is present.

3. If DTC P0118 can be repeated only by duplicating

the Failure Records conditions, refer to the

“Temperature vs. Resistance Value” table. The

table may be used to test the ECT sensor at various

temperatures to evaluate the possibility of a

“shifted” sensor that may be shorted above or below

a certain temperature. If this is the case, replace

the ECT sensor. If the ECT sensor appears to be

OK, the fault is intermittent; refer to

Diagnostic Aids

Engine Coolant Temperature Sensor

°C°F OHMS

Temperature vs. Resistance Values (approximate)

100 212 177

80 176 332

60 140 667

45 113 1188

35 95 1802

25 77 2796

15 59 4450

5 41 7280

–5 23 12300

–15 5 21450

–30 –22 52700

–40 –40 100700

DTC P0118 – ECT Sensor Circuit High Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Observe the “Eng Cool T emp” display on the T ech 2.

Is the “Eng Cool Temp” below the specified value? –39°CGo to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor the “DTC” info for DTC

P0118.

Does the Tech 2 indicate DTC P0118 failed? —Refer to

Test

Description

Refer to

Diagnostic

Aids

41. Disconnect the ECT sensor electrical connector.

2. Jumper the ECT signal circuit and the sensor

ground circuit together at the ECT sensor harness

connector.

3. Observe the “Eng Cool T emp” display on the T ech 2.

Is the “Eng Cool Temp” at the specified value? 151°CGo to

Step 6

Go to

Step 5

51. Jumper the ECT signal circuit at the ECT sensor

harness connector to chassis ground.

2. Observe the “Eng Cool T emp” display on the T ech 2.

Is the “Eng Cool Temp” at the specified value? 151°CGo to

Step 7

Go to

Step 8

6Check for poor connections at the ECT sensor and

replace terminals if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 10

71. Ignition “OFF.”

2. Disconnect the PCM, and check the ECT sensor

ground circuit for an open.

3. If the ECT sensor ground circuit is open, repair it as

necessary.

Was the ECT sensor ground circuit open? — Verify repair Go to

Step 9

81. Ignition “OFF.”

2. Disconnect the PCM, and check the ECT signal

circuit for an open.

3. If the ECT sensor signal circuit is open, repair it as

necessary.

Was the ECT signal circuit open? — Verify repair Go to

Step 9

9Check for a poor sensor ground or ECT signal circuit

terminal connection at the PCM and replace

terminal(s) if necessary.

Did any of the terminals need to be replaced? — Verify repair Go to

Step 11

10 Replace the ECT sensor.

Is the action complete? — Verify repair —

11 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0121 TP System Performance

D06RW059

Circuit Description

The throttle position (TP) sensor circuit provides a voltage

signal that changes relative to throttle blade angle. The

signal voltage will vary from about 0.6 volts at closed

throttle to about 4.5 volts at wide open throttle (WOT).

The TP signal is one of the most important inputs used by

the powertrain control module (PCM) for fuel control and

many of the PCM-controlled outputs. The PCM monitors

throttle position and compares actual throttle position

from the TP sensor to a predicted TP value calculated

from engine speed. If the PCM detects an out-of-range

condition, DTC P0121 will set.

Conditions for Setting the DTC

DThe engine is running.

DNo MAP DTCs, or P0121, P0123 DTCs are set.

DMAP reading is below 55 kPa.

DThrottle is steady, throttle angle is changing less than

1%.

DPredicted throttle angle is not close to actual throttle

angle.

DAbove conditions are present for a total of 12.5

seconds over a 25-second period of time.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

DThe PCM will use a default throttle position based on

mass air flow and RPM.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0121 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0121 can be cleared by using the Tech 2 “Clear

info ” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DSkewed MAP signal or faulty MAP sensor – An

incorrect MAP signal may cause the PCM to incorrectly

calculate the predicted TP sensor value during high

engine load situations. Check for an unusually low

MAP reading. This condition can cause DTC P0121 to

be set.

DThe TP Sensor shares a 5 V olt reference with the EGR

Valve.

If these codes are also set, it could indicate a

problem with the 5 Volt reference circuit or

components itself.

DThe TP Sensor share a ground with the EGR V alve and

the IAT Sensor.

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

ECT display on the Tech 2 while moving connectors

and wiring harnesses related to the sensor. A change

in the display will indicate the location of the fault.

If DTC P0121 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

DTC P0121 –TP System Performance

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine not running.

2. Observe the MAP reading on the Tech 2.

Is the MAP reading less than the specified value? 65 kPa Go to

Step 3

Go to

Step 6

31. Disconnected the MAP sensor.

2. Connect a test light between the 5 volt reference “A”

circuit and the MAP signal circuit at the MAP sensor

harness connector.

3. Observe the MAP reading on the Tech 2.

Is the MAP reading less than the specified value? (If no,

start with diagnosis chart for other sensors in the circuit

and see if 5V returns.) 65 kPa Go to

Step 5

Go to

Step 4

41. Check the MAP signal circuit between the PCM and

the MAP sensor for an open, short to ground, or

short to the MAP ground circuit.

2. If the MAP signal circuit is open or shorted, repair it

as necessary.

Was the MAP signal circuit open or shorted? — Verify repair Go to

Step 12

5Replace the MAP sensor.

Is the action complete? — Verify repair —

6Observe the TP angle reading on the Tech 2 while

slowly opening the throttle.

Does the TP angle increase steadily and evenly from

the closed throttle value to the wide open throttle

value?

Closed

throttle = 0%

Wide open

throttle =

100%

Refer to

Diagnostic

Aids

Go to

Step 7

71. Disconnect the TP sensor.

2. Observe the TP sensor reading on the Tech 2.

Is the TP sensor reading near the specified value? 0 V Go to

Step 8

Go to

Step 9

81. Connect a test light between the 5 volt reference “A”

circuit and the TP sensor signal circuit at the TP

sensor harness connector.

2. Observe the TP sensor reading on the Tech 2.

Is the TP sensor reading at the specified value? 5 V Go to

Step 11

Go to

Step 10

9Check the following items:

1. TP signal circuit for a short to voltage.

2. TP sensor ground circuit for high resistance

between the PCM and the TP sensor.

3. TP sensor ground circuit for a poor connection.

4. If a problem is found, repair wiring harness as

necessary.

Was a problem found? — Verify repair Go to

Step 12

Step NoYesValue(s)Action

10 Check the following items:

1. TP signal circuit or 5 volt reference “A” circuit for a

poor connection.

2. TP signal circuit or 5 volt reference “A” circuit for

high resistance between the PCM and the TP

sensor.

3. If a problem is found, repair wiring harness as

necessary.

Was a problem found? — Verify repair Go to

Step 12

11 Replace the TP sensor.

Is the action complete? — Verify repair —

12 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0122 TP Sensor Circuit Low Voltage

D06RW059

Circuit Description

The throttle position (TP) sensor circuit provides a voltage

signal that changes relative to throttle blade angle. The

signal voltage will vary from below 0.6 volts at closed

throttle to about 4.5 volts at wide open throttle (WOT).

The TP signal is used by the powertrain control module

(PCM) for fuel control and many of the PCM-controlled

outputs.

Conditions for Setting the DTC

DThe ignition is “ON.”

DTP sensor signal voltage is less than 0.22 volt for a total

of 0.78 second over a 1.5-second period.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

DThe PCM will use a default throttle position based on

mass air flow and RPM.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0122 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0122 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DThe TP Sensor shares a 5 V olt reference with the EGR

Valve.

If these codes are also set, it could indicate a

problem with the 5 Volt reference circuit or

components itself.

DThe TP Sensor share a ground with the EGR V alve and

the IAT Sensor.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

throttle position display on the Tech 2 while moving

connectors and wiring harnesses related to the TP

sensor. A change in the display will indicate the

location of the fault.

If DTC P0122 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

DTC P0122 –TP Sensor Circuit Low Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. With the throttle closed, observe the “TP Sensor”

display on the Tech 2.

Is the “TP Sensor” below the specified value? 0.22 V Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor the “DTC” info for DTC

P0122.

Does the Tech 2 indicate DTC P0122 failed? —Go to

Step 4

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect the TP sensor electrical connector.

3. Jumper the 5 volt reference “A” circuit and the TP

signal together at the TP sensor harness connector.

4. Ignition “ON.”

Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” at the specified value? 5 V Go to

Step 10

Go to

Step 5

51. Disconnect jumper.

2. Connect a test light between B+ and the TP sensor

signal circuit at the TP sensor harness connector.

Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” at the specified value? (If no, start

with diagnosis chart for other sensors in the circuit and

see if 5V returns.) 5 V Go to

Step 6

Go to

Step 8

61. Ignition “OFF.”

2. Disconnect the PCM and check the 5 volt reference

“A” circuit for an open or short to ground.

3. If the 5 volt reference “A” circuit is open or shorted to

ground, repair it as necessary.

Was the 5 volt reference “A” circuit open or shorted to

ground? — Verify repair Go to

Step 7

7Check the 5 volt reference “A” circuit for a poor

connection at the PCM and replace the terminal if

necessary.

Did the terminal require replacement? — Verify repair Go to

Step 12

81. Ignition “OFF.”

2. Disconnect the PCM, and check the TP signal

circuit for an open, short to ground, or short to the

sensor ground circuit.

3. If the TP sensor signal circuit is open or shorted to

ground, repair it as necessary.

Was the TP signal circuit open or shorted to ground? — Verify repair Go to

Step 9

Step NoYesValue(s)Action

9Check the TP sensor signal circuit for a poor

connection at the PCM and replace the terminal if

necessary.

Did the terminal require replacement? — Verify repair Go to

Step 12

10 Check the TP sensor signal circuit for a poor

connection at the TP sensor and replace the terminal if

necessary.

Did the terminal require replacement? — Verify repair Go to

Step 11

11 Replace the TP sensor.

Is the action complete? — Verify repair —

12 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0123 TP Sensor Circuit High Voltage

D06RW059

Circuit Description

The throttle position (TP) sensor circuit provides a voltage

signal that changes relative to throttle blade angle. The

signal voltage will vary from about 0.6 volts at closed

throttle to about 4.5 volts at wide open throttle (WOT).

The TP signal is one of the most important inputs used by

the powertrain control module (PCM) for fuel control and

many of the PCM-controlled outputs.

Conditions for Setting the DTC

DThe ignition is “ON.”

DTP sensor signal voltage is greater than 4.88 volts for

a total of 0.78 second over a 1.5-second period.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

DThe PCM will use a default throttle position based on

mass air flow and RPM.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0123 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0123 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DThe TP sensor shares a 5 Volt Reference with the EGR

Position sensor. Check the 5 Volt reference if these

DTCs are also set.

DThe TP sensor shares a ground with the IAT sensor

and the EGR position Sensor. Check the ground if

these other DTCs are also set.

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

TP sensor display on the Tech 2 while moving

connectors and wiring harnesses related to the TP

sensor. A change in the display will indicate the

location of the fault.

DFaulty TP sensor – With the ignition key “ON,” engine

“OFF,” observe the TP sensor display on the Tech 2

while slowly depressing the accelerator to wide open

throttle. If a voltage over 4.88 volts is seen at any point

in normal accelerator travel, replace the TP sensor.

If DTC P0123 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number (s) below refer to the step number(s) on the

Diagnostic Chart.

7. Components that share the TP sensor 5 volt reference

“A” circuit include the following device:

DEGR valve

Disconnect the component while observing the TP

sensor display on the Tech 2. If the reading

changes drastically when this component is

disconnected, replace the component that

affected the reading.

DTC P0123 – TP Sensor Circuit High Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. With the throttle closed, observe the “TP Sensor”

display on the Tech 2.

Is the “TP Sensor” above the specified value? 4.88 V Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0123.

Does the Tech 2 indicate DTC P0123 failed. —Go to

Step 4

Refer to

Diagnostic

Aids

41. Disconnect the TP sensor electrical connector.

2. Observe the “TP Sensor” display on the Tech 2.(If

no, start with diagnostic chart other sensors in the

circuit and see if 5 V returns)

Is the “TP Sensor” near the specified value? 0 V Go to

Step 5

Go to

Step 6

5Probe the sensor ground circuit at the TP sensor

harness connector with a test light connected to B+.

Is the test light “ON?” —Go to

Step 7

Go to

Step 10

61. Ignition “OFF,” disconnect the PCM.

2. Ignition “ON,” engine “OFF.”

3. Check for a short to voltage on the TP sensor signal

circuit.

4. If the TP sensor signal circuit is shorted, repair it as

necessary.

Was the TP sensor signal circuit shorted? — Verify repair Go to

Step 12

71. Ignition “ON.”

2. Monitor the “TP Sensor” Tech 2 display while

disconnecting each of the components that share

the 5 volt reference “A” circuit (one at a time).

3. If the “TP Sensor” Tech 2 display changes, replace

the component that caused the display to change

when disconnected.

Does disconnecting any of these components cause

the “TP Sensor” display to change? — Verify repair Go to

Step 8

Step NoYesValue(s)Action

81. Ignition “OFF,” disconnect the PCM.

2. Ignition “ON,” engine “OFF.”

3. Check for a short to B+ on the 5 volt reference “A”

circuit.

4. If the 5 volt reference “A” circuit is shorted, repair it

as necessary.

Was the 5 volt reference “A” circuit shorted? — Verify repair Go to

Step 9

9Check for poor electrical connections at the TP sensor

and replace terminals if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 11

10 1. Ignition “OFF.”

2. Disconnect the PCM, and check for an open sensor

ground circuit to the TP sensor.

3. If a problem is found, repair it as necessary.

W as the sensor ground circuit to the TP sensor open? —Verify repair Go to

Step 12

11 Replace the TP sensor.

Is the action complete? — Verify repair —

12 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC)

P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1

D06RX137

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) signal high and signal low circuits. When

measured with a 10 megaohm digital voltmeter , this may

display as low as 350 mV. The oxygen sensor varies the

voltage within a range of about 1000 mV when the

exhaust is rich, down through about 10 mV when exhaust

is lean. The PCM constantly monitors the HO2S signal

during “closed loop” operation and compensates for a rich

or lean condition by decreasing or increasing injector

pulse width as necessary. If the Bank 1 HO2S 1 voltage

remains excessively low for an extended period of time,

DTC P0131 will be set.

Conditions for Setting the DTC

DNo related DTCs.

DVehicle is operating in “closed loop.”

DEngine coolant temperature is above 60°C (140°F)

D“Closed loop” commanded air/fuel ratio is between

14.5 and 14.8.

DThrottle angle is between 3% and 19%.

DBank 1 HO2S 1 signal voltage remains below 22 mV

during normal “closed loop” operation for a total of 77

seconds over a 90-second period of time.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

D“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0131 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0131 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DHeated oxygen sensor wiring – The sensor pigtail may

be routed incorrectly and contacting the exhaust

system.

DPoor PCM to engine block grounds.

DFuel pressure – The system will go lean if pressure is

too low. The PCM can compensate for some

decrease. However, If fuel pressure is too low, a DTC

P0131 may be set. Refer to

Fuel System Diagnosis

DLean injector(s) – Perform “Injector Balance Test.”

DVacuum leaks – Check for disconnected or damaged

vacuum hoses and for vacuum leaks at the intake

manifold, throttle body, EGR system, and PCV system.

DExhaust leaks – An exhaust leak may cause outside air

to be pulled into the exhaust gas stream past the

HO2S, causing the system to appear lean. Check for

exhaust leaks that may cause a false lean condition to

be indicated.

DMAF sensor – The system can go lean if the MAF

sensor signal indicates an engine airflow

measurement that is not correct. Disconnect the MAF

sensor to see if the lean condition is corrected. If so,

replace the MAF sensor.

DFuel contamination – Water, even in small amounts,

can be delivered to the fuel injectors. The water can

cause a lean exhaust to be indicated. Excessive

alcohol in the fuel can also cause this condition. Refer

Fuel System Diagnosis

for the procedure to check

for fuel contamination.

DIf none of the above conditions are present, replace the

affected HO2S.

Test Description

Number(s) below refer to step numbers on the diagnostic

chart.

3. DTC P0131 failing during operation may indicate a

condition described in the “Diagnostic Aids” above.

If the DTC P0131 test passes while the Failure

Records conditions are being duplicated, an

intermittent condition is indicated.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0131 –HO2S Circuit Low Voltage Bank 1 Sensor 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Install the Tech 2.

2. Run the engine at operating temperature.

3. Operate the vehicle within the parameters specified

under “Conditions for Setting the DTC” criteria

included in Diagnostic Support.

4. Using a Tech 2, monitor Bank 1 HO2S 1 voltage.

Does the Bank 1 HO2S 1 voltage remain below the

specified value? 22 mV Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF ,” review and record T ech

2 Failure Records data and note parameters.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0131

until the DTC P0131 test runs.

Note test result.

Does Tech 2 indicate DTC P0131 failed this ignition? —Go to

Step 4

Refer to

Diagnostic

Aids

41. Turn the ignition “OFF.”

2. Disconnect the PCM.

3. Check the Bank 1 HO2S 1 high and low circuits for a

short to ground or a short to the heater ground

circuit.

Are the Bank 1 HO2S 1 signal circuits shorted to

ground? — Go to

Step 5

Go to

Step 6

5Repair the Bank 1 HO2S 1 signal circuit.

Is the action complete? — Verify repair —

61. Turn the ignition “OFF,” HO2S 1 and PCM

disconnected.

2. Check for continuity between the high and low

signal circuits.

Was there continuity between the high and low circuits? — Go to

Step 7

Go to

Step 8

7Repair the short between the high and low circuits.

Is the action complete? — Verify repair —

81. Ignition “OFF.”

2. Reconnect the PCM, leave the sensor

disconnected.

3. Ignition “ON.”

Does the Tech 2 indicate Bank 1 HO2S 1 voltage

between the specified values? 425–475 mV

Refer to

Diagnostic

Aids

Go to

Step 9

9Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC)

P0132 HO2S Circuit High Voltage Bank 1 Sensor 1

D06RX137

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) signal high and signal low circuits. When

measured with a 10 megaohm digital voltmeter, this may

display as low as 320 mV. The oxygen sensor varies the

voltage within a range of about 1000 mV when the

exhaust is rich, down through about 10 mV when exhaust

is lean. The PCM constantly monitors the HO2S signal

during “closed loop” operation and compensates for a rich

or lean condition by decreasing or increasing injector

pulse width as necessary. If the Bank 1 HO2S 1 voltage

remains excessively high for an extended period of time,

DTC P0132 will be set.

Conditions for Setting the DTC

DNo related DTCs.

DEngine coolant temperature is above 60°C (140°F)

D“Closed loop” commanded air/fuel ratio is between

14.5 and 14.8.

DThrottle angle is between 3% and 19%.

DBank 1 HO2S 1 signal voltage remains above 952 mV

during normal “closed loop” operation for a total of 77

seconds over a 90-second period.

DBank 1 HO2S 1 signal voltage remains above 500 mV

during “deceleration fuel cutoff mode” operation for 3

seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

D“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0132 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0132 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check the following items:

DFuel pressure – The system will go rich if pressure is

too high. The PCM can compensate for some

increase. However, if fuel pressure is too high, a DTC

P0132 may be set. Refer to

Fuel System Diagnosis

DPerform “Injector Balance Test” – Refer to

Fuel System

Diagnosis

DCheck the EVAP canister for fuel saturation – If full of

fuel, check canister control and hoses. Refer to

Evaporative (EVAP) Emission Control System

DMAF sensor –The system can go rich if MAF sensor

signal indicates an engine airflow measurement that is

not correct. Disconnect the MAF sensor to see it the

rich condition is corrected. If so, replace the MAF

sensor.

DCheck for a leak in the fuel pressure regulator

diaphragm by checking the vacuum line to the

regulator for the presence of fuel. There should be no

fuel in the vacuum line.

DAn intermittent TP sensor output will cause the system

to go rich due to a false indication of the engine

accelerating.

DShorted Heated Oxygen Sensor (HO2S) –If the HO2S

is internally shorted, the HO2S voltage displayed on

the Tech 2 will be over 1 volt. Try disconnecting the

affected HO2S with the key “ON,” engine “OFF.” If the

displayed HO2S voltage changes from over 1000 mV

to around 450 mV, replace the HO2S. Silicon

contamination of the HO2S can also cause a high

HO2S voltage to be indicated. This condition is

indicated by a powdery white deposit on the portion of

the HO2S exposed to the exhaust stream. If

contamination is noticed, replace the affected HO2S.

DOpen HO2S Signal Circuit or Faulty HO2S–A poor

connection or open in the HO2S signal circuit can

cause the DTC to set during deceleration fuel mode.

An HO2S which is faulty and not allowing a full voltage

swing between the rich and lean thresholds can also

cause this condition. Operate the vehicle by

monitoring the HO2S voltage with a Tech 2. If the

HO2S voltage is limited within a range between 300

mV to 600 mV, check the HO2S signal circuit wiring

and associated terminal conditions.

DIf none of the above conditions are present, replace the

affected HO2S.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. DTC P0132 failing during “deceleration fuel cutoff

mode” operation may indicate a condition described

in the “Diagnostic Aids” above. If the DTC P0132

test passes while the Failure Records conditions are

being duplicated, an intermittent condition is

indicated.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0132 – HO2S Circuit High Voltage Bank 1 Sensor 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Install the Tech 2.

2. Run the engine at operating temperature.

3. Operate the vehicle within parameters specified

under “Conditions for Setting the DTC” included in

Diagnostic Support.

4. Using a Tech 2, monitor Bank 1 HO2S 1 voltage.

Does the Bank 1 HO2S 1 voltage remain above the

specified value?

952 mV (500

mV in

deceleration

fuel cutoff

mode) Go to

Step 4

Go to

Step 3

31. Ignition “ON,” review and record Tech 2 Failure

Records data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0132

until the DTC P0132 test runs.

4. Note the test result.

Does the Tech 2 indicate DTC P0132 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect Bank 1 HO2S 1.

3. Ignition “ON.”

4. At HO2S Bank 1 Sensor 1 connector (PCM side)

use a DVM to measure voltages at the high and low

signal terminals.

Are the voltages in the specified range? 3-4 V Go to

Step 5

Go to

Step 6

5Repair short to voltage in signal circuit.

Is the action complete? — Verify repair —

61. Ignition “ON,” engine“OFF.”

2. At Bank 1 HO2S 1 connector (PCM side) jumper

both the HO2S high and low signal circuits (PCM

side) to ground.

3. Using a Tech 2, monitor Bank 1 HO2S 1 voltage.

Is Bank 1 HO2S 1 voltage below the specified value? 10 mV Go to

Step 7

Go to

Step 8

71. Disconnect the jumpers to ground from Bank 1

HO2S 1 PCM-side connector.

2. With the HO2S 1 connector disconnected, monitor

Bank 1 HO2S 1 voltage.

Is Bank 1 HO2S 1 voltage between the specified

values? 425-475 mV

Refer to

Diagnostic

Aids

Go to

Step 8

8Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0134 HO2S Circuit Insufficient Activity Bank 1

Sensor 1

D06RX138

Circuit Description

DThe powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) high and low circuits. When measured

with a 10 megaohm digital voltmeter, this may display

as low as 320 mV. The oxygen sensor varies the

voltage within a range of about 1000 mV when the

exhaust is rich, down through about 10 mV when

exhaust is lean. The PCM constantly monitors the

HO2S signal during “closed loop” operation and

compensates for a rich or lean condition by decreasing

or increasing injector pulse width as necessary. If the

Bank 1 HO2S 1 voltage remains at or near the 450 mV

bias for an extended period of time, DTC P0134 will be

set, indicating an open sensor signal or sensor low

circuit.

DHeated oxygen sensors are used to minimize the

amount of time required for “closed loop” fuel control

operation and to allow accurate catalyst monitoring.

The oxygen sensor heater greatly decreases the

amount of time required for fuel control sensors Bank

1 HO2S 1 and Bank 2 HO2S 1 to become active.

Oxygen sensor heaters are required by post-catalyst

monitor sensors to maintain a sufficiently high

temperature for accurate exhaust oxygen content

readings further from the engine.

Conditions for Setting the DTC

DNo related DTCs.

DBattery voltage is above 10 volts.

DEngine run time is longer than 40 seconds.

DOxygen sensor heater has been determined to be

functioning properly.

DBank 1 HO2S 1 signal voltage remains between 400

mV and 500 mV for a total of 77 seconds over a

90-second period of time.

Action Take When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

D“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0134 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0134 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection or damaged harness – Inspect the

harness connectors for backed-out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, poor terminal-to-wire connection,

and damaged harness.

DFaulty HO2S heater or heater circuit – With the ignition

“ON,” engine “OFF,” after a cool down period, the

HO2S 1 voltage displayed on the Tech 2 is normally

455-460 mV. A reading over 1000 mV indicates a

signal line shorted to voltage. A reading under 5 mV

indicates a signal line shorted to ground or signal lines

shorted together. Disconnect the HO2S and connect

a test light between the HO2S ignition feed and heater

ground circuits. If the test light does not light for 2

seconds when the ignition is turned on, repair the open

ignition feed or sensor ground circuit as necessary. If

the test light lights and the HO2S signal and low circuits

are OK, replace the HO2S.

DIntermittent test – With the Ignition “ON,” monitor the

HO2S signal voltage while moving the wiring harness

and related connectors. If the fault is induced, the

HO2S signal voltage will change. This may help isolate

the location of the malfunction.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. If the DTC P0134 test passes while the Failure

Records conditions are being duplicated, an

intermittent condition is indicated.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0134 –HO2S Circuit Insufficient Activity Bank 1 Sensor 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Install the Tech 2.

2. Run the engine at operating temperature.

3. Operate the engine above 1200 RPM for two

minutes.

Does the Tech 2 indicate Bank 1 HO2S 1 voltage

varying outside the specified values? 400-500 mV Go to

Step 3

Go to

Step 4

31. Ignition “ON,” engine “OFF ,” review and record T ech

2 Failure Records data and note parameters.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0134

until the DTC P0134 test runs.

4. Note the test result.

Does the Tech 2 indicate DTC P0134 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

4Check for a damaged harness.

Was a problem found? — Verify repair Go to

Step 5

5Check for poor Bank 1 HO2S 1 high and low circuit

terminal connections at the Bank 1 HO2S 1 harness

connector and replace terminal(s) if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 6

6Check for poor Bank 1 HO2S 1 high and low circuit

terminal connections at the PCM and replace terminals

if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 7

Step NoYesValue(s)Action

71. Ignition “OFF.”

2. With the PCM disconnected, check continuity of the

Bank 1 HO2S 1 high circuit.

3. If the Bank 1 HO2S 1 high circuit measures over 5.0

ohms, repair open or poor connection as necessary.

Was a Bank 1 HO2S 1 high circuit problem found and

corrected? — Verify repair Go to

Step 8

81. Ignition “OFF.”

2. With the PCM disconnected, check continuity of the

Bank 1 HO2S 1 low circuit.

3. If the Bank 1 HO2S 1 low circuit measures over 5

ohms, repair open or poor connection as necessary.

Was a Bank 1 HO2S 1 low circuit problem found and

corrected? —Verify repair Go to

Step 9

91. Ignition “ON,” engine “OFF.”

2. Disconnect Bank 1 HO2S 1 and jumper the HO2S

high and low circuits (PCM side) to ground.

3. Using a Tech 2, monitor Bank 1 HO2S 1 voltage.

Is Bank 1 HO2S 1 voltage in the specified range? 0-10 mV Go to

Step 10

Go to

Step 11

10 Replace Bank 1 HO2S 1.

Is the action complete? — Verify repair —

11 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0151 HO2S Circuit Low Voltage Bank 2

Sensor 1

D06RX139

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) signal high and signal low circuits. When

measured with a 10 megaohm digital voltmeter, this may

display as low as 320 mV. The oxygen sensor varies the

voltage within a range of about 1000 mV when the

exhaust is rich, down through about 10 mV when exhaust

is lean. The PCM constantly monitors the HO2S signal

during “closed loop” operation and compensates for a rich

or lean condition by decreasing or increasing injector

pulse width as necessary. If the Bank 2 HO2S 1 voltage

remains excessively low for an extended period of time,

DTC P0151 will be set.

Conditions for Setting the DTC

DNo related DTCs.

DThe engine is operating in “closed loop.”

DEngine coolant temperature is above 60°C (140°F).

D“Closed loop” commanded air/fuel ratio is between

14.5 and 14.8.

DThrottle angle is between 3% and 19%.

DBank 2 HO2S 1 signal voltage remains below 22 mV

during normal “closed loop” operation for a total of 77

seconds over a 90-second period of time.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

D“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0151 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0151 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DHeated oxygen sensor wiring – The sensor pigtail may

be mispositioned and contacting the exhaust system.

DPoor PCM to engine block grounds.

DFuel pressure – The system will go lean if pressure is

too low. The PCM can compensate for some

decrease. However, if fuel pressure is too low, a DTC

P0151 may be set. Refer to

Fuel System Diagnosis

DLean injector(s) – Perform “Injector Balance Test.”

DVacuum leaks – Check for disconnected or damaged

vacuum hoses and for vacuum leaks at the intake

manifold, throttle body, EGR system, and PCV system.

DExhaust leaks – An exhaust leak may cause outside air

to be pulled into the exhaust gas stream past the

HO2S, causing the system to appear lean. Check for

exhaust leaks that may cause a false lean condition to

be indicated.

DMAF sensor –The system can go lean if the MAF

sensor signal indicates an engine airflow

measurement that is not correct. Disconnect the MAF

sensor to see if the lean condition is corrected. If so,

replace the MAF sensor.

DFuel contamination – Water, even in small amounts,

can be delivered to the fuel injectors. The water can

cause a lean exhaust to be indicated. Excessive

alcohol in the fuel can also cause this condition. Refer

Fuel System Diagnosis

for the procedure to check

for fuel contamination.

DIf none of the above conditions are present, replace the

affected HO2S.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. DTC P0151 failing during operation may indicate a

condition described in the “Diagnostic Aids” above.

If the DTC P0151 test passes while the Failure

Records conditions are being duplicated, an

intermittent condition is indicate.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0151 — HO2S Circuit Low Voltage Bank 2 Sensor 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Install the Tech 2.

2. Run the engine at operating temperature.

3. Operate the vehicle within the parameters specified

under “Conditions for Setting the DTC” criteria

included in Diagnostic Support.

4. Using a Tech 2, monitor Bank 2 HO2S 1 voltage.

Does the Bank 2 HO2S 1 voltage remain below the

specified value? 22 mV Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF ,” review and record T ech

2 Failure Records data and note parameters.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0151

until the DTC P0151 test runs.

4. Note test result.

Does the Tech 2 indicate DTC P0151 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

41. Turn ignition “OFF.”

2. Disconnect the PCM.

3. Check the Bank 2 HO2S 1 high and low signal

circuits for a short to ground or a short to the heater

ground circuit.

Were Bank 2 HO2S 1 signal circuits shorted? —Go to

Step 5

Go to

Step 6

5Repair the Bank 2 HO2S 1 signal circuit.

Is the action complete? — Verify repair —

61. Ignition “OFF.”

2. Leave the PCM and HO2S 1 disconnected.

3. Check for continuity between the high and low

signal circuits.

Was there continuity between the high and low circuits? — Go to

Step 7

Go to

Step 8

Step NoYesValue(s)Action

7Repair the short between the high and low circuits.

Is the action complete? — Verify repair —

81. Ignition “OFF.”

2. Reconnect the PCM, leave HO2S 1 disconnected.

3. Ignition “ON.”

Does the Tech 2 indicate Bank 2 HO2S 1 voltage near

the specified value? 425-475 mV

Refer to

Diagnostic

Aids

Go to

Step 9

9Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0152 HO2S Circuit High Voltage Bank 2

Sensor 1

D06RX139

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) signal high and signal low circuits. When

measured with a 10 megaohm digital voltmeter, this may

display as low as 320 mV. The oxygen sensor varies the

voltage within a range of about 1000 mV when the

exhaust is rich, down through about 10 mV when exhaust

is lean. The PCM constantly monitors the HO2S signal

during “closed loop” operation and compensates for a rich

or lean condition by decreasing or increasing the injector

pulse width as necessary. If the Bank 2 HO2S 1 voltage

remains excessively high for an extended period of time,

DTC P0152 will be set.

Conditions for Setting the DTC

DNo related DTCs.

DThe engine is operating in “closed loop.”

DThe engine coolant temperature is above 60°C

(140°F).

D“Closed loop” commanded air/fuel ratio between 14.5

and 14.8.

DThrottle angle between 3% and 19%.

DBank 2 HO2S 1 signal voltage remains above 952 mV

during normal “closed loop” operation for a total of 77

seconds over a 90-second period.

DBank 2 HO2S 1 signal voltage remains above 500 mV

during deceleration fuel cutoff mode operation for up to

3 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

D“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0152 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0152 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DFuel pressure – The system will go rich if pressure is

too high. The PCM can compensate for some

increase. However, if fuel pressure is too high, a DTC

P0152 may be set. Refer to

Fuel System Diagnosis

DRich injector(s) – Perform “Injector Balance Test.”

DLeaking injector – Refer to

Fuel System Diagnosis

DEvaporative emissions (EVAP) system – Check the

canister for fuel saturation. If the canister is full of fuel,

check EVAP control system components and hoses.

Refer to

Evaporative Emission (EVAP) Control

System

DMAF sensor – The system can go rich if the MAF

sensor signal indicates an engine airflow

measurement that is not correct Disconnect the MAF

sensor to see if rich condition is corrected. If so,

replace MAF sensor.

DCheck for leaking fuel pressure regulator diaphragm by

checking vacuum line to regulator for the presence of

fuel. There should be no fuel in the vacuum line.

DTP sensor – An intermittent TP sensor output will

cause the system to go rich, due to a false indication

of the engine accelerating.

DShorted Heated Oxygen Sensor (HO2S)– If the HO2S

is internally shorted, the HO2S voltage displayed on

the Tech 2 will be over 1 volt. Try disconnecting the

affected HO2S with the key “ON,” engine “OFF.” If the

displayed HO2S voltage changes from over 1000 mV

to around 450 mV, replace the HO2S. Silicon

contamination of the HO2S can cause a high HO2S

voltage to be indicated. This condition is indicated by

powdery white deposit on the portion of the HO2S

exposed to the exhaust stream. If contamination is

noticed, replace the affected HO2S.

DOpen HO2S Signal Circuit of Faulty HO2S– A poor

connection or open in the HO2S signal circuit can

cause the DTC to set during deceleration fuel mode.

An HO2S which is faulty and not allowing a full voltage

switch between the rich and lean thresholds can also

cause the condition. Operate the vehicle while

monitoring the HO2S voltage with a Tech 2. If the

HO2S is voltage limited within a range between 300

mV to 600 mV, check the HO2S signal circuit wiring

and associated terminal connections.

DIf none of the above conditions are present, replace the

affected HO2S.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. DTC P0152 failing during deceleration fuel cutoff

mode operation may indicate a condition described

in the “Diagnostic Aids” above. If the DTC P0152

test passes while the Failure Records conditions are

being duplicated, an intermittent condition is

indicated.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0152 – HO2S Circuit High Voltage Bank 2 Sensor 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Install the Tech 2.

2. Engine is at operating temperature.

3. Operate the vehicle within the parameters specified

under “Conditions for Setting the DTC” criteria

included in Diagnostic Support.

4. Using a Tech 2, monitor Bank 2 HO2S 1 voltage.

Does the Bank 2 HO2S 1 voltage remain above the

specified value?

952 mV (500

mV in

deceleration

fuel cut-off

mode) Go to

Step 4

Go to

Step 3

31. Ignition “ON.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0152

until the DTC P0152 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0152 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

41. Ignition “OFF.”

2. Disconnect Bank 2 HO2S 1.

3. Ignition “ON.”

4. At HO2S Bank 2 Sensor 1 connector (PCM side)

use a DVM to measure voltages at the high and low

signal terminals.

Are the voltages in the specified range? 3-4 V Go to

Step 5

Go to

Step 6

5Repair short to voltage in signal circuit.

Is the action complete? — Verify repair —

61. Ignition “ON,” engine“OFF.”

2. At Bank 2 HO2S 1 connector (PCM side) jumper

both the HO2S high and low signal circuits (PCM

side) to ground.

3. Using a Tech 2, monitor Bank 2 HO2S 1 voltage.

Is Bank 2 HO2S 1 voltage below the specified value? 10 mV Go to

Step 7

Go to

Step 8

71. Disconnect the jumpers to ground from Bank 2

HO2S 1 PCM-side connector.

2. With the HO2S 1 connector disconnected, monitor

Bank 2 HO2S 1 voltage.

Is the Bank 2 HO2S 1 voltage between the specified

values? 425-475 mV

Refer to

Diagnostic

Aids

Go to

Step 8

8Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0154 HO2S Circuit Insufficient Activity Bank 2

Sensor 1

D06RX140

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) high and low circuits. When measured

with a 10 megaohm digital voltmeter, this may display as

low as 320 mV. The oxygen sensor varies the voltage

within a range of about 1000 mV when the exhaust is rich,

down through about 10 mV when exhaust is lean. The

PCM constantly monitors the HO2S signal during “closed

loop” operation and compensates for a rich or lean

condition by decreasing or increasing injector pulse width

as necessary . If the Bank 2 HO2S 1 voltage remains at or

near the 450 mV bias for an extended period of time, DTC

P0154 will be set, indicating an open sensor signal or

sensor low circuit.

Heated oxygen sensors are used to minimize the amount

of time required for “closed loop” fuel control operation

and to allow accurate catalyst monitoring. The oxygen

sensor heater greatly decreases the amount of time

required for fuel control sensors Bank 1 HO2S 1 and Bank

2 HO2S 1 to become active. Oxygen sensor heater are

required by post-catalyst monitor sensors to maintain a

sufficiently high temperature for accurate exhaust oxygen

content readings further from the engine.

Conditions for Setting the DTC

DNo related DTCs.

DBattery voltage is above 10 volts.

DEngine running time is longer than 40 seconds.

DOxygen sensor heater is functioning properly.

DBank 2 HO2S 1 signal voltage remains between 400

mV and 500 mV for a total of 77 seconds over a

90-second period of time.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

D“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0154 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0154 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection or damaged harness – Inspect the

harness connectors for backed-out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, poor terminal-to-wire-connection,

and damaged harness.

DFaulty HO2S heater or heater circuit – With the ignition

“ON,” engine “OFF,” the HO2S 1 voltage displayed on

the Tech 2 is normally 455-460 mV. A reading over

1000 mV indicates a signal line shorted to voltage. A

reading under 5 mV indicates a signal line shorted to

ground or signal lines shorted together. If not,

disconnect the HO2S and connect a test light between

the HO2S ignition feed and heater ground circuits. If

the test light does not light for 2 seconds when the

ignition is turned on, repair the open ignition feed or

sensor ground circuit as necessary. If the test light

lights and the HO2S signal and low circuits are OK,

replace the HO2S.

DIntermittent test – With the ignition “ON,” monitor the

HO2S signal voltage while moving the wiring harness

and related connectors. If the fault is induced, the

HO2S signal voltage will change. This may help isolate

the location of the malfunction.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. If the DTC P0154 test passes while the Failure

Records conditions are being duplicated, an

intermittent condition is indicated.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0154 – HO2S Circuit Insufficient Activity Bank 2 Sensor 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Install the Tech 2.

2. Run the engine at operating temperature.

3. Operate the engine above 1200 RPM for two

minutes.

Does the Tech 2 indicate Bank 2 HO2S 1 voltage

varying outside the specified values? 400-500 mV Go to

Step 3

Go to

Step 4

31. Ignition “ON,” engine “OFF.”

2. Review and record T ech 2 Failure Records data and

note parameters.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0154

until the DTC P0154 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0154 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

4Check for a damaged harness.

Was a problem found? — Verify repair Go to

Step 5

5Check for a poor Bank 2 HO2S 1 high and low circuit

terminal connections at the Bank 2 HO2S 1 harness

connector and replace terminal(s) if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 6

6Check for a poor Bank 2 HO2S 1 high and low circuit

terminal connections at the PCM and replace

terminal(s) if necessary.

Did the terminal require replacement? — Verify repair Go to

Step 7

Step NoYesValue(s)Action

71. Ignition “OFF.”

2. With the PCM disconnected check continuity of the

Bank 2 HO2S 1 low circuit.

3. If the Bank 2 HO2S 1 high circuit measures over 5.0

ohms, repair open or poor connection as necessary.

Was a Bank 2 HO2S 1 high circuit problem found and

corrected? — Verify repair Go to

Step 8

81. Ignition “OFF.”

2. With the PCM disconnected check continuity of the

Bank 2 HO2S 1 low circuit.

3. If the Bank 2 HO2S 1 low circuit measures over 5

ohms, repair open or poor connection as necessary.

Was a Bank 2 HO2S 1 low circuit problem found and

corrected? —Verify repair Go to

Step 9

91. Ignition “ON,” engine “OFF.”

2. Disconnect Bank 2 HO2S 1 and jumper the HO2S

high and low circuits (PCM side) to ground.

3. Using a Tech 2, monitor Bank 2 HO2S 1 voltage.

Is the Bank 2 HO2S 1 voltage in the specified range? 0-10 mV Go to

Step 10

Go to

Step 11

10 Replace Bank 2 HO2S 1.

Is the action complete? — Verify repair —

11 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0171 Fuel Trim System Too Lean Bank 1

D06RW068

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop”

air/fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank 1

HO2S 1 and Bank 2 HO2S 1 signals and adjusts fuel

delivery based upon the HO2S signal voltages. A change

made to fuel delivery will be indicated by the long and

short term fuel trim values which can be monitored with a

Tech 2. Ideal fuel trim values are around 0%; if the HO2S

signals are indicating a lean condition the PCM will add

fuel, resulting in fuel trim values above 0%. If a rich

condition is detected, the fuel trim values will be below

0%, indicating that the PCM is reducing the amount of fuel

delivered. If an excessively lean condition is detected on

Bank 1, the PCM will set DTC P0171.

The PCM’s maximum authority to control long term fuel

trim allows a range between –15% (automatic

transmission) or –12% (manual transmission) and +20%.

The PCM monitors fuel trim under various engine

speed/load fuel trim cells before determining the status

the fuel trim diagnostic.

Conditions for Setting the DTC

DNo Tech 2 test is being run.

DNone of the following: EGR DTCs, HO2S DTCs,

(response, transition, open, low volts, no activity), MAF

DTCs, TP sensor DTCs, MAP DTCs, IAT DTCs,

canister purge DTCs, EVAP DTCs, injector circuit

DTCs, or misfire DTCs.

DEngine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

DIntake air temperature is between –40°C (–40°F) and

120°C (248°F).

DManifold absolute pressure is between 24 kPa and 99

kPa.

DThrottle angle is steady below 95%.

DVehicle speed is below 136 km/h (85 mph).

DEngine speed is between 400 and 6000 RPM.

DBarometric pressure is greater than 72.5 kPa.

DMass air flow (MAF) is between 2 g/second and 200

g/second.

DIgnition voltage is above 9.5 volts.

DFuel system is in “closed loop.”

DCanister purge duty cycle is greater than 0% if on.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0171 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0171 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Bank 1 HO2S 1 display on the Tech 2 while moving

connectors and wiring harnesses related to the engine

harness. A change in the display will indicate the

location of the fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0171 and P0174 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0171/P0174.

4. If the DTC P0171 test passes while the Failure

Records conditions are being duplicated, the lean

condition is intermittent. Refer to

Diagnostic Aids

Symptoms

for additional information on diagnosing

intermittent problems.

DTC P0171 –Fuel Trim System Lean Bank 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Are any DTCs set other than P0171 and P0174?

—

Go to the

applicable

DTC charts

and repair the

other DTCs

before

proceeding

with this chart Go to

Step 3

31. Start the engine and operate the vehicle in “closed

loop.”

2. Observe the “B1 Long Term Fuel Trim” display on

the Tech 2.

Is the displayed value greater than the specified value? L.T. Fuel

Trim: +20% Go to

Step 5

Go to

Step 4

41. Review and record the T ech 2 Failure Records data.

2. Clear the DTC P0171/P0174 and operate the

vehicle to duplicate the Failure Records conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0171 while

operating the vehicle to duplicate the Failure

Records conditions.

4. Continue operating the vehicle until the DTC P0171

test runs and note the test result.

Does the Tech 2 indicate DTC P0171 failed this

ignition? — Go to

Step 5

The lean

condition is

not present.

If a

driveability

symptom still

exists, refer

Symptoms

section.

5Was DTC P0174 also set? —Go to

Step 6

Go to

Step 15

6Visually and physically inspect the vacuum hoses for

disconnections, splits, kinks, improper routing and

improper connections and repair any problem found.

Did your inspection reveal a problem requiring repair? —Verify repair Go to

Step 7

7Visually and physically inspect the crankcase

ventilation valve for proper installation and repair any

problem found (refer to

Crankcase Ventilation

System

Did your inspection reveal a problem requiring repair? — Verify repair Go to

Step 8

81. Inspect the MAF sensor inlet screen for damage or

for the presence of foreign objects which may

partially block the air flow sample through the MAF

sensor.

2. Correct any problem that is found as necessary.

Did your inspection of the MAF sensor reveal a

condition requiring repair? — Verify repair Go to

Step 9

9Start the engine and note the idle quality.

Is a high or unsteady idle being experienced? —Go to

Step 10

Go to

Step11

10 1. Visually and physically inspect the throttle body,

intake manifold, EGR valve and the EGR feed pipe

for vacuum leaks.

2. Repair any vacuum leaks as necessary.

Did your inspection reveal a vacuum leak? — Verify repair Go to

Step 11

Step NoYesValue(s)Action

11 Check the fuel for excessive water, alcohol, or other

contaminants (see

Diagnosis

Engine Fuel

for the

procedure) and correct the contaminated fuel condition

if present (see

Engine Fuel

Was the fuel contaminated? — Verify repair Go to

Step 12

12 1. Visually and physically inspect the PCM injector

grounds, power grounds and sensor grounds to

ensure that they are clean, tight, and in their proper

locations.

2. If a faulty ground condition is present, correct it as

necessary.

Did your inspection reveal a condition requiring repair? —Verify repair Go to

Step 13

13 1. Disconnect the MAF sensor electrical connector.

2. Operate the vehicle in “closed loop” while

monitoring the “B1 Long Term Fuel T rim” displayed

on the Tech 2.

Does “BANK 1 S.T. FUEL TRIM” value decrease to

near the specified value? 0% Go to

Step 19

Go to

Step 14

14 Perform the procedure in the “Fuel System Pressure

Test” and repair fuel system problem if necessary.

Did Fuel System Pressure Test isolate a condition

requiring repair? — Verify repair Go to

Step 15

15 1. Visually and physically inspect the intake manifold,

injector O-rings, EGR adapter, EGR valve and the

EGR feed pipes for vacuum leaks.

2. Repair any problem that is found.

Did your inspection reveal a problem? — Verify repair Go to

Step 16

16 Visually and physically inspect the Bank 1 exhaust

manifold for leaks and loose or missing hardware and

correct any problem found.

Did your inspection reveal a problem? — Verify repair Go to

Step 17

17 Perform the “Injector Balance Test,” and correct any

problem found (refer to

Fuel Metering System

Did Injector Balance Test isolate a problem? — Verify repair Go to

Step 18

18 1. Visually and physically inspect the Bank 1 HO2S 1

to ensure that it is installed securely and that the

Bank 1 HO2S 1 pigtail and wiring harness are not

contacting the exhaust or otherwise damaged.

2. If a problem is found, correct it as necessary.

Did your inspection reveal a problem? — Verify repair

Refer to

Diagnostic

Aids

19 Replace the MAF sensor.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0172 Fuel Trim System Rich Bank 1

D06RW068

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop”

air/fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank 1

heated oxygen sensors (HO2S) 1 and Bank 2 HO2S 1

signals and adjusts fuel delivery based upon the HO2S

signal voltages. A change made to fuel delivery will be

indicated by the long and short term fuel trim values which

can be monitored with a Tech 2. Ideal fuel trim values are

around 0%; if the HO2S signals are indicating a lean

condition the PCM will add fuel, resulting in fuel trim

values above 0%. If a rich condition is detected, the fuel

trim values will be below 0%, indicating that the PCM is

reducing the amount of fuel delivered. If an excessively

rich condition is detected on Bank 1, the PCM will set DTC

P0172.

The PCM’s maximum authority to control long term fuel

trim allows a range between –15% (automatic

transmission) or –12 (manual transmission) and +20%.

The PCM’s maximum authority to control short term fuel

trim allows a range between –11% and +20%. The PCM

monitors fuel trim under various engine speed/load fuel

trim cells before determining the status of the fuel trim

diagnostic.

Conditions for Setting the DTC

DNo Tech 2 test is being run.

DNone of the following was set: EGR DTCs, HO2S

DTCs, (response, transition, open, low volts, no

activity), MAF DTCs, TPS DTCs, MAP DTCs, IAT

DTCs, canister purge DTCs, EVAP DTCs, injector

circuit DTCs, or misfire DTCs.

DEngine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

DIntake air temperature is between –40°C (–40°F) and

120°C (248°F).

DManifold absolute pressure is between 24 kPa and 99

kPa.

DThrottle angle is steady below 95%.

DVehicle speed is below 136 km/h (85 mph).

DEngine speed is between 400 and 6000 RPM.

DBarometric pressure is greater than 72.5 kPa.

DMass air flow (MAF) is between 2 g/second and 200

g/second.

DIgnition voltage is above 9.5 volts.

DFuel system is in “closed loop.”

DCanister purge duty cycle is greater than 0%, if “ON.”

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0172 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0172 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Bank 1 HO2S 1 display on the Tech 2 while moving

connectors and wiring harnesses related to the engine

harness. A change in the display will indicate the

location of the fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0172 and P0175 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0172/P0175.

4. If the DTC P0172 test passes while the Failure

Records conditions are being duplicated, the rich

condition is intermittent. Refer to

Diagnostic Aids

Symptoms

for additional information on diagnosing

intermittent problems.

DTC P0172 – Fuel Trim System Rich Bank 1

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Are any DTCs set other than P0172 and P0175?

—

Go to the

applicable

DTC charts

and repair the

other DTCs

before

proceeding

with this chart Go to

Step 3

31. Start the engine and operate the vehicle in “closed

loop.”

2. Observe “B1 Long Term Fuel Trim” display on the

Tech 2.

Is the displayed value more negative than the specified

value?

L.T. Fuel

Trim: –15%

(auto. trans.)

OR –12%

(man. trans.) Go to

Step 5

Go to

Step 4

41. Review and record the T ech 2 Failure Records data.

2. Clear the DTC P0172/P0175 and operate the

vehicle to duplicate the Failure Records conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0172 while

operating the vehicle to duplicate the Failure

Records conditions.

4. Continue operating the vehicle until the DTC P0172

test runs and note test result.

Does the Tech 2 indicate DTC P0172 failed this

ignition? — Go to

Step 5

The rich

condition is

not present.

If a

driveability

symptom still

exists, refer

Symptoms

5Is DTC P0175 also set? —Go to

Step 6

Go to

Step 15

6Visually and physically inspect the air filter element and

replace it if necessary.

Did the air filter require replacement? — Verify repair Go to

Step 7

7Visually and physically inspect the air intake duct for

collapse or restriction and repair if necessary.

Did your inspection reveal a condition requiring repair? —Verify repair Go to

Step 8

8Inspect the MAF sensor inlet screen for damage or for

the presence of foreign objects which may partially

block air flow through the screen and correct any

problem found.

Did your inspection of the MAF sensor reveal a

condition requiring repair or replacement? — Verify repair Go to

Step 9

9Start the engine and note the idle quality.

Is a low or unsteady idle being experienced? —Go to

Step 10

Go to

Step 11

10 1. Ignition “OFF.”

2. Physically inspect the throttle body bore, throttle

plate, and IAC passages for coking and foreign

objects.

3. If a problem was found, repair as necessary.

Did your inspection reveal a condition requiring repair? —Verify repair Go to

Step 11

Step NoYesValue(s)Action

11 1. Disconnect the vacuum hose from the fuel pressure

regulator and inspect the hose for the presence of

fuel.

2. If fuel is present in the vacuum hose, replace the

fuel pressure regulator (refer to

Fuel Metering

System

Did the fuel pressure regulator require replacement? — Verify repair Go to

Step 12

12 Ignition “ON,” engine “OFF,” monitor the TP display on

the Tech 2 while slowly depressing the accelerator

pedal.

Does the TP Angle display increase steadily and

evenly from minimum value at closed throttle to

maximum value at wide–open throttle?

Minimum 0%

Maximum

100% Go to

Step 13

Go to

Step 20

13 1. Disconnect the MAF sensor electrical connector.

2. Operate the vehicle in “closed loop” while

monitoring the “B1 Long Term Fuel Trim” and “B1

Short Term Fuel Trim” display on the Tech 2.

Did both values change to near the specified value? 0% Go to

Step 21

Go to

Step 14

14 1. Ignition “ON,” engine “OFF.”

2. Connect a test light between the harness connector

terminals of canister purge solenoid.

Is the test light on? —Go to

Step 15

Go to

Step 18

15 Check for short to ground in the wire (red/blue)

between the canister purge solenoid and PCM terminal

A-15.

Was there a short to ground? —Go to

Step 16

Go to

Step 17

16 Repair the short to ground.

Is the action complete? — Verify repair —

17 Replace the PCM.

Is the action complete? — Verify repair —

18 1. Perform the “Injector Balance Test.”

2. If Injector Balance T est isolates a problem, repair as

necessary (refer to

Fuel Metering System

Did the Injector Balance Test isolate a problem

requiring repair? — Verify repair Go to

Step 19

19 1. Remove and visually/physically inspect the Bank 1

HO2S 1 for silicon contamination. This will be

indicated by a powdery white deposit on the portion

of the HO2S that is exposed to the exhaust stream.

2. If contamination is evident on the Bank 1 HO2S 1,

replace the contaminated sensors.

Did the sensor require replacement? — Verify repair

Refer to

Diagnostic

Aids

20 1. Check the TP sensor mounting screws and tighten

or replace them as necessary if they are loose or

missing.

2. If the screws are OK, replace the TP sensor.

Is the action complete? — Verify repair —

21 Replace the MAF sensor.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0174 Fuel Trim System Lean Bank 2

D06RW069

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop”

air/fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank 1

HO2S 1 and Bank 2 HO2S 1 signals and adjusts fuel

delivery based upon the HO2S signal voltages. A change

made to fuel delivery will be indicated by the long and

short term fuel trim values which can be monitored with a

Tech 2. Ideal fuel trim values are around 0%; if the HO2S

signals are indicating a lean condition the PCM will add

fuel, resulting in fuel trim values above 0%. If a rich

condition is detected, the fuel trim values will be below

0%, indicating that the PCM is reducing the amount of fuel

delivered. If an excessively lean condition is detected on

Bank 2, the PCM will set DTC P0174.

The PCM’s maximum authority to control long term fuel

trim allows a range between –15%(automatic

transmission) or –12%(manual transmission) and +20%.

The PCM monitors fuel trim under various engine

speed/load fuel trim cells before determining the status of

the fuel trim diagnostic.

Conditions for Setting the DTC

DNo Tech 2 test is being run.

DNone of the following DTCs are set: idle system, EGR,

HO2S, (response, transition, open, low volts, no

activity), MAF, TP sensor, MAP, IAT, canister purge,

EVAP, injector circuit, or misfire.

DEngine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

DIntake air temperature is between –40°C (–40°F) and

120°C (248°F).

DManifold absolute pressure is between 24 kPa and 99

kPa.

DThrottle angle is steady below 95%.

DVehicle speed is below 136 km/h (85 mph).

DEngine speed is between 400 and 6000 RPM.

DBarometric pressure is greater than 72.5 kPa.

DMass air flow is between 2 g/second and 200 g/second.

DIgnition voltage is above 9.5 volts.

DFuel system is in “closed loop.”

DCanister purge duty cycle is greater than 15%, if “ON.”

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

failure is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0174 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0174 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Bank 2 HO2S 1 display on the Tech 2 while moving

connectors and wiring harnesses related to the engine

harness. A change in the display will indicate the

location of the fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0171 and P0174 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0171/P0174.

4. If the DTC P0174 test passes while the Failure

Records conditions are being duplicated, the lean

condition is intermittent. Refer to

Diagnostic Aids

Symptoms

for additional information on diagnosing

intermittent problems.

DTC P0174 – Fuel Trim System Lean Bank 2

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Are any DTCs set other than P0174 and P0171?

—

Go to the

applicable

DTC charts

and repair the

other DTCs

before

proceeding

with this

chart. Go to

Step 3

31. Start the engine and operate the vehicle in “closed

loop.”

2. Observe the “B2 Long Term Fuel Trim” display on

the Tech 2.

Is the displayed values greater than the specified

values? L.T. Fuel

Trim: +20% Go to

Step 5

Go to

Step 4

41. Review and record Tech 2 Failure Records data.

2. Clear the DTC P0171/P0174 and operate the

vehicle to duplicate the Failure Records conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0174 while

operating the vehicle to duplicate the Failure

Records conditions.

4. Continue operating the vehicle until the DTC P0174

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0174 failed this

ignition? — Go to

Step 5

The lean

condition is

not present.

If a

driveability

symptom still

exists, refer

Symptoms

section.

5Was DTC P0171 also set? —Go to

Step 6

Go to

Step 15

6Visually and physically inspect the vacuum hoses for

disconnects, splits, kinks, improper routing and

improper disconnections and repair any problem

found.

Did your inspection reveal a problem requiring repair? — Verify repair Go to

Step 7

7Visually and physically inspect the crankcase

ventilation valve for proper installation and repair any

problem found (refer to

Crankcase Ventilation

System

Did your inspection reveal a problem requiring repair? —Verify repair Go to

Step 8

81. Inspect the MAF sensor inlet screen for damage or

for the presence of foreign objects which may

partially block the air flow sample through the MAF

sensor.

2. Correct any problem that is found as necessary.

Did your inspection of the MAF sensor reveal a

condition requiring repair? — Verify repair Go to

Step 9

9Start the engine and note the idle quality.

Is a high or unsteady idle being experienced? —Go to

Step 10

Go to

Step 11

Step NoYesValue(s)Action

10 1. Visually and physically inspect the throttle body,

intake manifold, EGR valve and the EGR feed pipe

for vacuum leaks.

2. Repair any vacuum leaks as necessary.

Did your inspection reveal a vacuum leak? — Verify repair Go to

Step 11

11 Check the fuel for excessive water, alcohol, or other

contaminants (see

Diagnosis

Engine Fuel

for

procedure) and correct the contaminated fuel condition

is present (see

Engine Fuel

Was the fuel contaminated? — Verify repair Go to

Step 12

12 1. Visually and physically inspect the PCM injector

grounds, power grounds and sensor grounds to

ensure that they are clean, tight, and in their proper

locations.

2. If a faulty ground condition is present, correct it as

necessary.

Did your inspection reveal a condition requiring repair? —Verify repair Go to

Step 13

13 1. Disconnect the MAF sensor electrical connector.

2. Operate the vehicle in “closed loop” while

monitoring the “B2 Short Term Fuel T rim” displayed

on the Tech 2.

Does the “B2 Short Term Fuel T rim” value decrease to

near the specified value? 0% Go to

Step 19

Go to

Step 14

14 Perform the procedure in the ”Fuel System Pressure

Test” and repair fuel system problem if necessary.

Did the Fuel System Pressure Test isolate a condition

requiring repair? — Verify repair Go to

Step 15

15 1. Visually and physically inspect the intake manifold,

injector O-rings, EGR adapter, EGR valve and the

EGR feed pipes for vacuum leaks.

2. Repair any problem that is found.

Did your inspection reveal a problem? — Verify repair Go to

Step 16

16 Visually and physically inspect the Bank 2 exhaust

manifold for leaks and loose or missing hardware and

correct any problem found.

Did your inspection reveal a problem? — Verify repair Go to

Step 17

17 Perform the “Injector Balance Test,” and correct any

problem found (refer to

Fuel Metering System

Did the Injector Balance Test isolate a problem? — Verify repair Go to

Step 18

18 1. Visually and physically inspect the Bank 2 HO2S 1

to ensure that it is installed securely and that the

Bank 2 HO2S 1 pigtail and wiring harness are not

contacting the exhaust or otherwise damaged.

2. If a problem is found, correct it as necessary.

Did your inspection reveal a problem? — Verify repair

Refer to

Diagnostic

Aids

19 Replace the MAF sensor.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0175 Fuel Trim System Rich Bank 2

D06RW069

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop”

air/fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank 1

HO2S 1 and Bank 2 HO2S 1 signals and adjusts fuel

delivery based upon the HO2S signal voltages. A change

made to fuel delivery will be indicated by the long and

short term fuel trim values which can be monitored with a

Tech 2. Ideal fuel trim values are around 0%; if the HO2S

signals are indicating a lean condition the PCM will add

fuel, resulting in fuel trim values above 0%. If a rich

condition is detected, the fuel trim values will be below

0%, indicating that the PCM is reducing the amount of fuel

delivered. If an excessively rich condition is detected on

Bank 2, the PCM will set DTC P0175.

The PCM’s maximum authority to control long term fuel

trim allows a range between –15%(automatic

transmission) or –12%(manual transmission) and +20%.

The PCM’s maximum authority to control short term fuel

trim allows a range between –11% and +20%. The PCM

monitors fuel trim under various engine speed/load fuel

trim cells before determining the status of the fuel trim

diagnostic.

Conditions for Setting the DTC

DNo Tech 2 test is being run.

DNone of the following DTCs are set: idle system, EGR,

HO2S, (response, transition, open, low volts, no

activity), MAF, TPS, MAP, IAT, canister purge, EVAP,

injector circuit, or misfire.

DEngine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

DIntake air temperature is between –40°C (–40°F) and

120°C (248°F).

DManifold absolute pressure is between 24 kPa and 99

kPa.

DThrottle angle is steady below 95%.

DVehicle speed is below 136 km/h (85 mph).

DEngine speed is between 400 and 6000 RPM.

DBarometric pressure is greater than 72.5 kPa.

DMass air flow (MAF) is between 2 g/second and 200

g/second.

DIgnition voltage is above 9.5 volts.

DFuel system is in “closed loop.”

DCanister purge duty cycle is greater than 15%, if “ON.”

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

failure is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0175 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0175 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Bank 2 HO2S 1 display on the Tech 2 while moving

connectors and wiring harnesses related to the engine

harness. A change in the display will indicate the

location of the fault.

Reviewing the Failure Records Vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0172 and P0175 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0172/P0175.

4. If the DTC P0175 test passes while the Failure

Records conditions are being duplicated, the rich

condition is intermittent. Refer to

Diagnostic Aids

Symptoms

for additional information on diagnosing

intermittent problems.

DTC P0175 – Fuel Trim System Rich Bank 2

Step Action Value(s) YesNo

1Was the ”On-Board Diagnostic (OBD) System Check”

performed? —Go to Step 2

Go to

OBD

System

Check

2Are any DTCs set other than P0172 and P0175?

—

Go to the

applicable

DTC charts

and repair the

other DTCs

before

proceeding

with this

chart. Go to

Step 3

31. Start the engine and operate the vehicle in “closed

loop.”

2. Observe the “BANK 2 L.T. FUEL TRIM” display on

the Tech 2.

Is the displayed value more negative than the specified

value?

L.T. Fuel

Trim: –15%

(auto. trans.)

OR –12%

(man. trans.) Go to

Step 5

Go to

Step 4

41. Review and record the T ech 2 Failure Records data.

2. Clear the DTC P0172/P0175 and operate the

vehicle to duplicate the Failure Records conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0175 while

operating the vehicle to duplicate the Failure

Records conditions.

4. Continue operating the vehicle until the DTC P0175

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0175 failed this

ignition? — Go to

Step 5

The rich

condition is

not present.

If a

driveability

symptom still

exists, refer

Symptoms

5Was DTC P0172 also set? —Go to

Step 6

Go to

Step 15

6Visually and physically inspect the air filter element and

replace it if necessary.

Did the air filter require replacement? — Verify repair Go to

Step 7

Step NoYesValue(s)Action

7Visually and physically inspect the air intake duct for

collapse or restriction and repair if necessary.

Did your inspection reveal a problem requiring repair? —Verify repair Go to

Step 8

8Inspect the MAF sensor inlet screen for damage or for

the presence of foreign objects which may partially

block air flow through the screen and correct any

problem found.

Did your inspection of the MAF sensor reveal a

condition requiring repair or replacement? — Verify repair Go to

Step 9

9Start the engine and note the idle quality.

Is a low or unsteady idle being experienced? —Go to

Step 10

Go to

Step 11

10 1. Turn the ignition off and physically inspect the

throttle body bore, throttle plate, and IAC passages

for coking and foreign objects.

2. If a problem was found, repair as necessary.

Did your inspection reveal a condition requiring repair? —Verify repair Go to

Step 11

11 1. Disconnect the vacuum hose from the fuel pressure

regulator and inspect the hose for the presence of

fuel.

2. If fuel is present in the vacuum hose, replace the

fuel pressure regulator (refer to

Fuel Metering

System

Did the fuel pressure regulator require replacement? — Verify repair Go to

Step 12

12 1. Ignition “ON,” engine “OFF.”

2. Monitor the TP Angle display on the Tech 2 while

slowly depressing the accelerator pedal.

Does the TP Angle display increase steadily and

evenly from minimum value at closed throttle to

maximum value at wide-open throttle?

Minimum 0%

Maximum

100% Go to

Step 13

Go to

Step 21

13 1. Disconnect the MAF sensor electrical connector.

2. Operate the vehicle in “closed loop” while

monitoring the “B1 Lont T erm Fuel Trim” and “BANK

2 S.T. FUEL TRIM” display on the Tech 2.

Did both values change to near the specified value? 0% Go to

Step 22

Go to

Step 14

14 1. Ignition “ON,” engine “OFF.”

2. Connect a test light between the harness connector

terminals of canister purge solenoid.

Is the test light on? —Go to

Step 15

Go to

Step 18

15 Check for short to ground in the wire (red/blue)

between the canister purge solenoid and PCM terminal

A-15.

Was there a short to ground? —Go to

Step 16

Go to

Step 17

16 Repair the short to ground.

Is the action complete? — Verify repair —

17 Replace the PCM.

Is the action complete? — Verify repair —

Step NoYesValue(s)Action

18 1. Perform the “Injector Balance Test.”

2. If the Injector Balance Test isolates a problem,

repair as necessary (refer to

Fuel Metering

System

Did the Injector Balance Test isolate a problem

requiring repair? — Verify repair Go to

Step 19

19 1. Remove and visually/physically inspect the Bank 2

HO2S 1 for silicon contamination. This will be

indicated by a powdery white deposit on the portion

of the HO2S that is exposed to the exhaust stream.

2. If contamination is evident on the Bank 2 HO2S 1,

replace the contaminated sensor.

Did the sensor require replacement? — Verify repair

Refer to

Diagnostic

Aids

20 1. Check the TP sensor mounting screws and tighten

or replace them as necessary if they are loose or

missing.

2. If the screws are OK, replace the TP sensor.

Is the action complete? — Verify repair —

21 Replace the MAF sensor.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0201 Injector 1 Control Circuit

D06RW070

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector . When a

driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to detect

a fault. If the voltage is not what the PCM expects to

monitor on the circuit, a DTC is set. This DTC is also set if

an injector driver is shorted to voltage or if there is an open

circuit.

Conditions for Setting the DTC

DThe battery voltage is more than 9 volts.

DThe engine is turning, determined by 58X crankshaft

position input signal.

DThe injector voltage does not equal the ignition voltage

when the injector is commanded “OFF” or the injector

voltage does not equal 0 volts when the injector is

commanded “ON.”

DThe above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn “OFF” the MIL on the third

consecutive trip cycle in which the diagnostic has been

run and the fault is no longer present.

DA history DTC P0201 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0201 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage

will cause a DTC P0201 to set. It will also cause a misfire

due to an inoperative injector. A misfire DTC will also be

set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0201 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 1 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel

Injector Coil Test Procedure will check if the

injectors are faulty.

R321054

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded

at all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9.The reading should be about 12-14W.

10.Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0201 – Injector 1 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Will the engine start?

—Go to

Step 3

Go to

Engine

Cranks But

Will Not Run

chart

31. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0201 reset? —Go to

Step 5

Go to

Step 4

41. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0201 reset? —Go to

Step 5

Go to

Diagnostic

Aids

Step NoYesValue(s)Action

51. Engine “OFF.”

2. Disconnect the injector connector.

3. Install an injector test light 5-8840-2636-0 on the

injector test connector.

4. Crank the engine and note the light.

Does the injector test light blink? —

Go to

Fuel

Injector Coil

Test

Procedure

Go to

Step 6

6Note whether the injector test light for cylinder 1 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to

Step 7

Go to

Step 9

71. Disconnect the PCM connector for the affected

injectors.

2. With a test light connected to B+, probe the affected

injector driver circuit.

Does the test light illuminate? —Go to

Step 8

Go to

Step 15

8Repair short to ground in the injector driver circuit.

Is the action complete? —

Go to

OBD

System

Check

—

91. Disconnect the injector test connector.

2. At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 1 (green with white

tracer).

Does the ohmmeter indicate continuity? —Go to

Step 11

Go to

Step 10

10 Repair the open injector harness wire or open injector .

Is the action complete? — Verify repair —

11 At the PCM side of the injector test connector, check

the green/white wire for a short to voltage.

Was there a short to voltage? —Go to

Step 12

Go to

Step 13

12 Repair the short to voltage.

Is the action complete? — Verify repair —

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit? —Go to

Step 14

Go to

Step 15

14 Repair the open circuit.

Is the action complete? — Verify repair —

15 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0202 Injector 2 Control Circuit

D06RW070

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector . When a

driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to detect

a fault. If the voltage is not what the PCM expects to

monitor on the circuit, a DTC is set. This DTC is also set if

an injector driver is shorted to voltage or if there is an open

circuit.

Conditions for Setting the DTC

DThe battery voltage is more than 9 volts.

DThe engine is turning, determined by 58X crankshaft

position input signal.

DThe injector voltage does not equal the ignition voltage

when the injector is commanded “OFF” or the injector

voltage does not equal 0 volts when the injector is

commanded “ON.”

DThe above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn “OFF” the MIL on the third

consecutive trip cycle in which the diagnostic has been

run and the fault is no longer present.

DA history DTC P0202 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0202 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage

will cause a DTC P0202 to set. It will also cause a misfire

due to an inoperative injector. A misfire DTC will also be

set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0202 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 2 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321055

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded

at all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9.The reading should be about 12-14W.

10.Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0202 – Injector 2 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Will the engine start?

—Go to

Step 3

Go to

Engine

Cranks But

Will Not Run

chart

31. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0202 reset? —Go to

Step 5

Go to

Step 4

41. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0202 reset? —Go to

Step 5

Go to

Diagnostic

Aids

Step NoYesValue(s)Action

51. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on

injector test connector

4. Crank the engine and note the light.

Does the cylinder 2 test light blink? —

Go to

Fuel

Injector Coil

Test

Procedure

Go to

Step 6

6Note whether the injector test light for cylinder 2 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to

Step 7

Go to

Step 9

71. Disconnect the PCM connector for the affected

injectors.

2. With a test light connected to B+, probe the affected

injector driver circuit.

Does the test light illuminate? —Go to

Step 8

Go to

Step 15

8Repair short to ground in the injector driver circuit.

Is the action complete? —

Go to

OBD

System

Check

—

91. Disconnect the injector test connector.

2. At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 2 (green with orange

tracer).

Does the ohmmeter indicate continuity? —Go to

Step 11

Go to

Step 10

10 Repair the open injector harness wire or open injector .

Is the action complete? — Verify repair —

11 At the PCM side of the injector test connector, check

the green/orange wire for a short to voltage.

Was there a short to voltage? —Go to

Step 12

Go to

Step 13

12 Repair the short to voltage.

Is the action complete? — Verify repair —

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit? —Go to

Step 14

Go to

Step 15

14 Repair the open circuit.

Is the action complete? — Verify repair —

15 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0203 Injector 3 Control Circuit

D06RW070

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to detect

a fault. If the voltage is not what the PCM expects to

monitor on the circuit, a DTC is set. This DTC is also set if

an injector driver is shorted to voltage or if there is an open

circuit.

Conditions for Setting the DTC

DThe battery voltage is more than 9 volts.

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe injector voltage does not equal the ignition voltage

when the injector is commanded “OFF” or the injector

voltage does not equal 0 volts when the injector is

commanded “ON.”

DThe above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn “OFF” the MIL on the third

consecutive trip cycle in which the diagnostic has been

run and the fault is no longer present.

DA history DTC P0203 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0203 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage

will cause a DTC P0203 to set. It will also cause a misfire

due to an inoperative injector. A misfire DTC will also be

set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0203 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 3 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel

Injector Coil Test Procedure will check if the

injectors are faulty.

R321056

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded

at all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9.The reading should be about 12-14W.

10.Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0203 – Injector 3 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Will the engine start?

—Go to

Step 3

Go to

Engine

Cranks But

Will Not Run

chart

31. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0203 reset? —Go to

Step 5

Go to

Step 4

41. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0203 reset? —Go to

Step 5

Go to

Diagnostic

Aids

Step NoYesValue(s)Action

51. Engine “OFF.”

2. Disconnect the injector test connector .

3. Install an injector test light 5-8840-2636-0 on

injector connector

4. Crank the engine and note the light.

Does the cylinder 3 test light blink? —

Go to

Fuel

Injector Coil

Test

Procedure

Go to

Step 6

6Note whether the injector test light for cylinder 3 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to

Step 7

Go to

Step 9

71. Disconnect the PCM connector for the affected

injectors.

2. With a test light connected to B+, probe the affected

injector driver circuit.

Does the test light illuminate? —Go to

Step 8

Go to

Step 15

8Repair short to ground in the injector driver circuit.

Is the action complete? —

Go to

OBD

System

Check

—

91. Disconnect the injector test connector.

2. At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 3 (green).

Does the ohmmeter indicate continuity? —Go to

Step 11

Go to

Step 10

10 Repair the open injector harness wire or open injector .

Is the action complete? — Verify repair —

11 At the PCM side of the injector test connector, check

the green wire for a short to voltage.

Was there a short to voltage? —Go to

Step 12

Go to

Step 13

12 Repair the short to voltage.

Is the action complete? — Verify repair —

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit? —Go to

Step 14

Go to

Step 15

14 Repair the open circuit.

Is the action complete? — Verify repair —

15 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0204 Injector 4 Control Circuit

D06RW070

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to detect

a fault. If the voltage is not what the PCM expects to

monitor on the circuit, a DTC is set. This DTC is also set if

an injector driver is shorted to voltage or if there is an open

circuit.

Conditions for Setting the DTC

DThe battery voltage is more than 9 volts.

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe injector voltage does not equal the ignition voltage

when the injector is commanded “OFF” or the injector

voltage does not equal 0 volts when the injector is

commanded “ON.”

DThe above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn “OFF” the MIL on the third

consecutive trip cycle in which the diagnostic has been

run and the fault is no longer present.

DA history DTC P0204 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0204 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage

will cause a DTC P0204 to set. It will also cause a misfire

due to an inoperative injector. A misfire DTC will also be

set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0204 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 4 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel

Injector Coil Test Procedure will check if the

injectors are faulty.

R321057

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded

at all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9.The reading should be about 12-14W.

10.Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0204 – Injector 4 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Will the engine start?

—Go to

Step 3

Go to

Engine

Cranks But

Will Not Run

chart

31. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0204 reset? —Go to

Step 5

Go to

Step 4

41. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0204 reset? —Go to

Step 5

Go to

Diagnostic

Aids

Step NoYesValue(s)Action

51. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on

injector test connector.

4. Crank the engine and note the light.

Does the cylinder 4 test light blink? —

Go to

Fuel

Injector Coil

Test

Procedure

Go to Step 6

6Note whether the injector test light was “OFF” or “ON”

steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to

Step 7

Go to

Step 9

71. Disconnect the PCM connector for the affected

injectors.

2. With a test light connected to B+, probe the affected

injector driver circuit.

Does the test light illuminate? —Go to

Step 8

Go to

Step 15

8Repair short to ground in the injector driver circuit.

Is the action complete? —

Go to

OBD

System

Check

—

91. Disconnect the injector test connector.

2. At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 4 (green/red).

Does the ohmmeter indicate continuity? —Go to

Step 11

Go to

Step 10

10 Repair the open injector harness wire or open injector .

Is the action complete? — Verify repair —

11 At the PCM side of the injector test connector, check

the green/red wire for a short to voltage.

Was there a short to voltage? —Go to

Step 12

Go to

Step 13

12 Repair the short to voltage.

Is the action complete? — Verify repair —

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit? —Go to

Step 14

Go to

Step 15

14 Repair the open circuit.

Is the action complete? — Verify repair —

15 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0205 Injector 5 Control Circuit

D06RW070

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to detect a

fault. If the voltage is not what the PCM expects to

monitor on the circuit, a DTC is set. This DTC is also set if

an injector driver is shorted to voltage or if there is an open

circuit.

Conditions for Setting the DTC

DThe battery voltage is more than 9 volts.

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe injector voltage does not equal the ignition voltage

when the injector is commanded “OFF” or the injector

voltage does not equal 0 volts when the injector is

commanded “ON.”

DThe above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn “OFF” the MIL on the third

consecutive trip cycle in which the diagnostic has been

run and the fault is no longer present.

DA history DTC P0205 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0205 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage

will cause a DTC P0205 to set. It will also cause a misfire

due to an inoperative injector. A misfire DTC will also be

set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0205 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 5 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321058

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded

at all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9.The reading should be about 12-14W.

10.Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0205 – Injector 5 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Will the engine start?

—Go to

Step 3

Go to

Engine

Cranks But

Will Not Run

chart

31. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0205 reset? —Go to

Step 5

Go to

Step 4

41. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0205 reset? —Go to

Step 5

Go to

Diagnostic

Aids

Step NoYesValue(s)Action

51. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on the

injector test connector.

4. Crank the engine and note the light.

Does the cylinder 5 test light blink? —

Go to

Fuel

Injector Coil

Test

Procedure

Go to

Step 6

6 Note whether the injector test light was “OFF” or “ON”

steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to

Step 7

Go to

Step 9

71. Disconnect the PCM connector for the affected

injectors.

2. With a test light connected to B+, probe the affected

injector driver circuit.

Does the test light illuminate? —Go to

Step 8

Go to

Step 15

8Repair short to ground in the injector driver circuit.

Is the action complete? —

Go to

OBD

System

Check

—

91. Disconnect the injector test connector.

2. At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 5 (green with black

tracer).

Does the ohmmeter indicate continuity? —Go to

Step 11

Go to

Step 10

10 Repair the open injector harness wire or open injector .

Is the action complete? — Verify repair —

11 At the PCM side of the injector test connector, check

the green/black wire for a short to voltage.

Was there a short to voltage? —Go to

Step 12

Go to

Step 13

12 Repair the short to voltage.

Is the action complete? — Verify repair —

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit? —Go to

Step 14

Go to

Step 15

14 Repair the open circuit.

Is the action complete? — Verify repair —

15 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0206 Injector 6 Control Circuit

D06RW070

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to detect

a fault. If the voltage is not what the PCM expects to

monitor on the circuit, a DTC is set. This DTC is also set if

an injector driver is shorted to voltage or if there is an open

circuit.

Conditions for Setting the DTC

DThe battery voltage is more than 9 volts.

DThe engine is turning, determined by 58X crankshaft

position input signal.

DThe injector voltage does not equal the ignition voltage

when the injector is commanded “OFF” or the injector

voltage does not equal 0 volts when the injector is

commanded “ON.”

DThe above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn “OFF” the MIL on the third

consecutive trip cycle in which the diagnostic has been

run and the fault is no longer present.

DA history DTC P0206 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0206 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage

will cause a DTC P0206 to set. It will also cause a misfire

due to an inoperative injector. A misfire DTC will also be

set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0206 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 6 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel

Injector Coil Test Procedure will check if the

injectors are faulty.

R321059

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded

at all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9.The reading should be about 12-14W.

10.Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0206 – Injector 6 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Will the engine start?

—Go to

Step 3

Go to

Engine

Cranks But

Will Not Run

chart

31. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0206 reset? —Go to

Step 5

Go to

Step 4

41. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0206 reset? —Go to

Step 5

Go to

Diagnostic

Aids

Step NoYesValue(s)Action

51. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on

injector test connector.

4. Crank the engine and note the light.

Does the cylinder 6 test light blink? —

Go to

Fuel

Injector Coil

Test

Procedure

Go to

Step 6

6Note whether the injector test light was “OFF” or “ON”

steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to

Step 7

Go to

Step 9

71. Disconnect the PCM connector for the affected

injectors.

2. With a test light connected to B+, probe the affected

injector driver circuit.

Does the test light illuminate? —Go to

Step 8

Go to

Step 15

8Repair short to ground in the injector driver circuit.

Is the action complete? —

Go to

OBD

System

Check

—

91. Disconnect the injector test connector.

2. At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 6 (green with yellow

tracer).

Does the ohmmeter indicate continuity? —Go to

Step 11

Go to

Step 10

10 Repair the open injector harness wire or open injector

Is the action complete? — Verify repair —

11 At the PCM side of the injector test connector, check

the green/yellow wire for a short to voltage.

Was there a short to voltage? —Go to

Step 12

Go to

Step 13

12 Repair the short to voltage.

Is the action complete? — Verify repair —

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit? —Go to

Step 14

Go to

Step 15

14 Repair the open circuit.

Is the action complete? — Verify repair —

15 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0325 KS Module Circuit

D06RW035–1

Circuit Description

The knock sensor is used to detect engine detonation,

allowing the powertrain control module (PCM) to retard

ignition control (IC) spark timing based on the knock

sensor (KS) signal being received. The knock sensor

produces an AC signal so that under a no knock condition

the signal on the KS circuit measures about 0.007 V AC.

The KS signal’s amplitude and frequency depend upon

the amount of knock being experienced. The PCM

contains a non-replaceable knock filter module called a

signal-to-noise enhancement filter (SNEF) module. This

filter module in the PCM determines whether knock is

occurring by comparing the signal level on the KS circuit

with the voltage level on the noise channel. The noise

channel allows the PCM to reject any false knock signal

by knowing the amount of normal engine mechanical

noise present. Normal engine noise varies depending on

engine speed and load. When the PCM determines that

an abnormally low noise channel voltage level is being

experienced, a DTC P0325 will set.

Conditions for Setting the DTC

DEngine has been running for at least 30 seconds.

DThe PCM determines that its internal signal from its

knock filter module indicates a continuous knocking

condition for more than 10 seconds.

Action Taken When the DTC Sets

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

DThe PCM will use a “substitute” default spark retard

value of 6 degrees to minimize knock during conditions

when knock is likely to occur.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0325 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0325 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect the knock sensor

and PCM connectors for backed-out terminals, broken

locks, and improperly formed or damaged terminals.

DMisrouted harness – Inspect the knock sensor harness

to ensure that it is not routed too close to high voltage

circuits such as spark plug coils.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

DTC P0325 – KS Module Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2IMPORTANT:If an engine knock can be heard, repair

the engine mechanical problem before proceeding with

this diagnostic.

1. Operate the vehicle within parameters specified

under criteria included in “Conditions for Setting the

DTC.”

2. Using a Tech 2, monitor “DTC” info for DTC P0325

until the DTC P0325 test runs.

3. Note the test result.

Does the Tech 2 indicate DTC P0325 failed this

ignition? — Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data for

DTC P0325.

3. Operate the vehicle within Failure Records

conditions.

4. Using a Tech 2, monitor “DTC” info for DTC P0325

until the DTC P0325 test runs.

Does the Tech 2 indicate DTC P0325 test failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

4Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0327 KS Sensor Circuit

D06RW035–1

Circuit Description

The powertrain control module (PCM) uses the knock

sensor to detect engine detonation, allowing the PCM to

retard ignition control (IC) spark timing based on the

knock sensor (KS) signal being received. The knock

sensor produces an AC signal so that under a no knock

condition the signal on the KS circuit measures about

0.007 V AC. The signal amplitude and frequency are

dependent upon the amount of knock being experienced.

The PCM monitors the KS signal and can diagnose the

KS sensor and circuitry.

Conditions for Setting the DTC

DEngine running time is at least 10 seconds.

DThe TP sensor is greater than 5%.

DThe ECT sensor is greater than 60°C (140°F).

DEngine speed is between 2000 and 4000 RPM.

DThe knock sensor signal voltage is less than 0.20 volts,

or greater than 4.8 volts.

DAll conditions are present for more than 15 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

DThe PCM will use a calculated spark retard value to

minimize knock during conditions when knock is likely

to occur. The calculated value will vary based on

engine speed and load.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0327 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0327 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

DTC P0327 – KS Sensor Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2IMPORTANT:If an engine knock can be heard, repair

the engine mechanical problem before proceeding with

this diagnostic.

1. Operate the engine within the conditions specified

in diagnostic support “Conditions for Setting the

DTC.”

2. Using a Tech 2, monitor “DTC” info for DTC P0327

until the DTC P0327 test runs.

3. Note the test result.

Does the Tech 2 indicate DTC P0327 failed this

ignition? — Go to

Step 4

Go to

Step 3

31. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions.

4. Using a Tech 2, monitor “DTC” info for DTC P0327

until the DTC P0327 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0327 failed this

ignition? — Go to

Step 4

Refer to

Diagnostic

Aids

4Using a test light to battery +, check the black/blue wire

(PCM side) to verify that the shield connection is good.

Did the test light illuminate? —Go to

Step 6

Go to

Step 5

5Repair the open shield ground.

Is the action complete? — Verify repair —

61. Ignition “OFF,” disconnect the PCM.

2. Check the KS signal circuit for a poor terminal

connection at the PCM.

3. If a problem is found, replace the faulty terminal.

Was a problem found? — Verify repair Go to

Step 7

71. Ignition “OFF,” PCM disconnected.

2. Check the KS signal circuit between the PCM and

the knock sensor connector for an open, a short to

voltage, or a short to ground.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

81. Ignition “OFF,” PCM disconnected.

2. Knock sensor connected.

3. Measure the resistance of the knock sensor by

connecting the DVM between the PCM connector

and the engine block.

Is the resistance of the knock sensor near the specified

value? 100K ohms Go to

Step 9

Go to

Step 10

Step NoYesValue(s)Action

91. Ignition “OFF,” PCM disconnected.

2. Connect the DVM to monitor AC voltage between

the PCM connector and engine ground.

3. Tap on the engine lift bracket with a socket

extension while observing the signal indicated on

the DVM.

Is any signal indicated on the DVM while tapping on the

engine lift bracket? —Go to

Step 11

Go to

Step 10

10 Replace the knock sensor.

Is the action complete? — Verify repair —

11 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0336 58X Reference Signal Circuit

D06RX145

Circuit Description

The 58X reference signal is produced by the crankshaft

position (CKP) sensor . During one crankshaft revolution,

58 crankshaft pulses will be produced. The powertrain

control module (PCM) uses the 58X reference signal to

calculate engine RPM and crankshaft position. The PCM

constantly monitors the number of pulses on the 58X

reference circuit and compares them to the number of

camshaft position (CMP) signal pulses being received. If

the PCM receives an incorrect number of pulses on the

58X reference circuit, DTC P0336 will set.

Conditions for Setting the DTC

DEngine is running.

DExtra or missing pulse is detected between

consecutive 58X reference pulses.

DAbove condition is detected in 10 of 100 crankshaft

rotations.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0336 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0336 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed–through wire insulation or a wire broken inside the

insulation. Check for:

DPoor connection – Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, disconnect

the PCM, turn the ignition on and observe a voltmeter

connected to the 58X reference circuit at the PCM

harness connector while moving connectors and

wiring harnesses related to the ICM. A change in

voltage will indicate the location of the fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0336 – 58X Reference Signal Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Attempt to start the engine.

Does the engine start? —Go to

Step 3

Go to

“Engine

Cranks But

Will Not Run”

chart

31. Review and record Failure Records information.

2. Clear DTC P0336.

3. Start the engine and idle for 1 minute.

4. Observe DTCs.

Is DTC P0336 set? —Go to

Step 4

Refer to

Diagnostic

Aids

41. Disconnect the PCM and CKP sensor.

2. Check for an open or a short to ground in the 58X

reference circuit between the CKP sensor

connector and the PCM harness connector.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 5

51. Reconnect the PCM and CKP sensor.

2. Connect a DVM to measure voltage on the 58X

reference circuit at the PCM connector.

3. Observe the voltage while cranking the engine.

Is the voltage near the specified value? 2.5 V Go to

Step 8

Go to

Step 6

6Check the connections at the CKP sensor and replace

the terminals if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 7

7Replace the CKP sensor . Use caution to avoid any hot

oil that may drip out.

Is the action complete? — Verify repair —

8Check connections at the PCM and replace the

terminals if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 10

9Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0337 CKP Sensor Circuit Low Frequency

D06RX145

Circuit Description

The 58X reference signal is produced by the crankshaft

position (CKP) sensor . During one crankshaft revolution,

58 crankshaft reference pulses will be produced. The

powertrain control module (PCM) uses the 58X reference

signal to calculate engine RPM and crankshaft position.

The PCM constantly monitors the number of pulses on

the 58X reference circuit and compares them to the

number of camshaft position (CMP) signal pulses being

received. If the PCM does not receive pulses on the 58X

reference circuit, DTC P0337 will set.

Conditions for Setting the DTC

DNo camshaft position (CMP) sensor DTCs are set.

DEngine cranking.

DCrankshaft position (CKP) sensor signal is not present

between two cam pulses.

DCKP reference pulse is not detected within 8 CMP

pulses.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0337 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0337 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside the

insulation. Check for:

DPoor connection – Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, disconnect

the PCM, turn the ignition on and observe a voltmeter

connected to the 58X reference circuit at the PCM

harness connector while moving connectors and

wiring harnesses related to the ICM. A change in

voltage will indicate the location of the fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0337 – CKP Sensor Circuit Low Frequency

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Attempt to start the engine.

Does the engine start? —Go to

Step 3

Go to

Chart 3

31. Review and record Failure Records information.

2. Clear DTC P0337.

3. Start the engine and idle for 1 minute.

4. Observe DTCs.

Is DTC P0337 set? —Go to

Step 4

Refer to

Diagnostic

Aid

41. Disconnect the CKP sensor.

2. Ignition “ON.”

3. Using a DVM, verify that 5 V reference and ground

are being supplied at the sensor connector (PCM

side).

Are 4-6 volts and ground available at the sensor? —Go to

Step 7

Go to

Step 5

51. Ignition “ON.”

2. With a DVM, backprobe the PCM connector 5 V

reference and ground connections.

Are 5 V reference and ground available at the PCM? —Go to

Step 6

Go to

Step 11

6Check 5 V reference or ground between the CKP

sensor and PCM and repair the open circuit, short to

ground or short to voltage.

Is the action complete? — Verify repair —

71. Ignition “OFF.”

2. Disconnect the PCM and CKP sensor.

3. Check for an open or a short to ground in the 58X

reference circuit between the CKP sensor

connector and the PCM harness connector.

4. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

81. Reconnect the PCM and CKP sensor.

2. Connect a DVM to measure voltage on the 58X

reference circuit at the PCM connector.

3. Observe the voltage while cranking the engine.

Is the voltage near the specified value? 2.5 V Go to

Step 11

Go to

Step 9

Step NoYesValue(s)Action

9Check the connections at the CKP sensor and replace

the terminals if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 10

10 Replace the CKP sensor. Use caution and avoid hot oil

that may drip out.

Is the action complete? — Verify repair —

11 Check the connections at the PCM and replace the

terminals if necessary.

Did any terminals require replacement? — Verify repair Go to

Step 12

12 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0341 CMP Sensor Circuit Performance

D06RWO32

Circuit Description

The CMP signal is produced by the cam shaft position

(CMP) sensor pulses whe n the engine is running and the

crankshaft position (CKP) sync pulse s are also being

received.

The powertrain cont rol module (PCM) uses the CMP sig nal

pulses to initiate sequential fuel injection. The PCM

constantly monitors the number of pul ses on the CMP

signal circuit and compare s the number of CMP pulses to

the number of 58X reference pulses received.

If the PCM receives an incorrect number of pulses o n the

CMP reference circuit, DTCP0341 will set and the PCM will

initiate injector sequence without the CMP si gnal with a one

in six chance that injector sequence is co rrect.

The engine will continue to start and run normally, althoug h

the misfire diagnostic will be affected if a misfiring condition

occurs.

Conditions for Setting the DTC

• The engine is running (1X CMP reference pulses are

being received).

• The CMP sensor signal is not detected at the correct

interval every 6 cylinders.

• Above condition fails for 100 occurrences within 200

test samples.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator lamp

(MIL) after the second conse cutive trip in which the

fault is detected.

• The PCM will initiate the injector sequen ce without the

CMP signal with a one in six chance that the injector

sequence is correct.

• The PCM will store conditions whi ch were present

when the DTC was set as Fr eeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0341 can be cleared by using the Tech 2

‘Clear Info’ function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside

the insulation. Check for:

• Poor connection - Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK,

disconnect the PCM, turn the ignition on and

observe a voltmeter connected to the CMP signal

circuit at the PCM harness connector while moving

connectors and wiring harnesses related to the PCM

and the CMP sensor. A change in voltage will

indicate the location of the fault.

Reviewing the Failure Records vehicle mileage since

the diagnostic test last failed may help determine

how often the condition that caused the DTC to be

set occurs. This may assist in diagnosing the

condition.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

12. Determines whether the fault is being caused by a

faulty sensor. The Tech 2 reading should toggle

between 4 volts, to near 0 volts, as the screwdriver

blade is wiped across the sensor end.

DTC P0341 - CMP Sensor Circuit Performance

Step Action Value(s) Yes No

1 Was the “On-Board Diagnostic (OBD) System

Check” performed? – Go to Step 2 Go to (OBD)

System Check

2 1. Ignition "ON."

2. Review and record Tech 2 Failure Records

data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using Tech 2, monitor "Specific DTC" info for

DTC P0341 until the DTC P0341 test runs.

5. Note the test result.

Does Tech 2 indicate DTC P0341 failed this

ignition? – Go to Step 3 Refer to

Diagnostic Aids

3 1. Disconnect the CMP sensor.

2. Using a DMM, measure the voltage between

the sensor feed circuit and the sensor

ground circuit at the CMP sensor ha rness

connector.

Does the voltage measure near the specified

value? 4 – 6 V Go to Step 4 Go to Step 5

4 Measure the voltage between the CMP sensor

signal circuit and the sensor ground circuit at the

CMP sensor harness connector.

Does the voltage measure near the specified

value? 4 – 6 V Go to Step 11 Go to Step

5 If the voltage measured in step 3 was less than 4

– 0 volts, proceed directly to step 6 without

completing this step.

If the voltage in step 3 was greater than 4 – 6 V,

repair the short to voltage in the CMP feed circuit.

Is the action complete? – Verify repair –

6 1. Check for poor connections at the camshaft

position sensor.

2. If a problem is found, repair as necessary.

Was a problem found? – Verify repair Go to Step 7

Step Action Value(s) Yes No

7 1. Ignition ‘OFF’ disconnect the PCM and the

CMP sensor.

2. Check the following circuits for an open

between the ignition coil and the CMP sensor:

• The sensor feed circuit.

3. If a problem is found, repair as necessary.

Was a problem found? – Verify repair Go to Step 9

8 1. Ignition ‘OFF’, disconnect the PCM (leave the

CMP sensor disconnected).

2. Ignition "ON," check the following circuits:

• The CMP sensor signal circuit for an open

or a short to voltage.

• The CMP sensor input signal circuit for a

short to ground.

3. If a problem is found, repair it as necessary.

Was a problem found? – Verify repair Go to Step 9

9 Check for a short or open in the sensor ground

circuit.

Was a problem found and corrected? – Verify repair Go to Step 10

10 1. Check for poor connections at the PCM.

2. If a problem is found, repair as necessary.

Was a problem found? – Verify repair Go to Step 11

11 Backprobe the PCM connector with a DMM to

monitor voltage on the camshaft position input

signal circuit while cranking the engine with the

sensor connected.

(Use rubber band, tape, or an assistant to keep

the DMM lead in contact with the sensor terminal

during this test.)

Does the voltage toggle between the specified

values? 4 – 0 V Go to Step 14 Go to Step 12

12 1 Disconnect the CMP wiring harness

connector.

2. Remove the CMP sensor, then reconnect the

wiring harness connector.

3. Turn ignition ‘ON’.

4. Move the shank of a large screwdriver back

and forth across the face of the sensor, (close

but not touching).

5. Monitor the CMP signal on the Tech 2 Data

Display.

Does the voltage signal vary as specified?

Fluctuates

between

0 and 4

volts Go to Step 14 Go to Step 13

13 Replace the camshaft position sensor.

Is the action complete? – Verify repair –

14 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A – 6VE1

Immobiliser.

Is the action complete? – Verify repair –

Diagnostic Trouble Code (DTC) P0342 CMP Sensor Circuit Low

D06RX145

Circuit Description

The CMP signal produced by the camshaft position

(CMP) sensor pulses when the engine is running and

crankshaft position (CKP) sync pulses are also being

received. The hall type CMP sensor and the CKP sensor

share 5 V and ground connections at the powertrain

control module (PCM). The third wire at the sensor is a

signal circuit to the PCM. The PCM uses the CMP signal

pulses to initiate sequential fuel injection. The PCM

constantly monitors the number of pulses on the CMP

signal circuit and compares the number of CMP pulses to

the number of 58X reference pulses received. If the PCM

does not receive pulses on the CMP reference circuit,

DTC P0342 will set and the PCM will initiate injector

sequence without the CMP signal with a one in six chance

that injector sequence is correct. The engine will continue

to start and run normally, although the misfire diagnostic

will be affected if a misfiring condition occurs.

Conditions for Setting the DTC

DThe engine is running.

DThe CMP sensor signal is not received by the PCM

once every 6 cylinders.

DThe above condition occurs for 10 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will initiate injector sequence without the

CMP signal with a one in six chance that the injector

sequence is correct.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0342 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0342 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside the

insulation. Check for:

DPoor connection – Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal to wire connection.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, disconnect

the PCM, turn the ignition on and observe a voltmeter

connected to the CMP signal circuit at the PCM

harness connector while moving connectors and

wiring harnesses related to the ICM and the CMP

sensor. A change in voltage will indicate the location

of the fault.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

12.Determines whether the fault is being caused by a

damaged camshaft or a faulty PCM. The voltage

measured in this step should read around 4 volts,

toggling to near 0 volts when the CMP sensor

interfaces with the camshaft magnet.

DTC P0342 —CMP Sensor Circuit Low

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” information for DTC

P0342 until the DTC P0342 test runs.

5. Note test result.

Does the Tech 2 indicate DTC P0342 failed this

ignition? — Go to

Step 3

Refer to

Diagnostic

Aids

31. Ignition “ON.”

2. Disconnect the CMP sensor.

3. Measure the voltage between the sensor feed

circuit and the sensor ground circuit at the CMP

sensor harness connector.

Does the voltage measure near the specified value? 4-6 V Go to

Step 7

Go to

Step 4

41. Ignition “OFF,” disconnect the PCM and the CMP

sensor.

2. Check for poor connections at the camshaft

position sensor.

3. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair Go to

Step 5

51. Check for poor connections at the PCM.

2. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair Go to

Step 6

61. Check the following circuits between the PCM and

the CMP sensor:

DThe sensor feed circuit. Open or short to

ground?

DThe sensor ground circuit. Open or short to

voltage?

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair —

71. Ignition “ON,” engine “OFF.”

2. Measure the voltage between the CMP sensor

signal circuit and the sensor ground circuit at the

CMP sensor harness connector.

Does the voltage measure near the specified value? 4-6 V Go to

Step 8

Go to

Step 9

Step NoYesValue(s)Action

81. Turn the ignition “OFF.”

2. Disconnect the PCM and connect a DVM to monitor

voltage on the camshaft position signal circuit at the

PCM connector.

3. Ignition “ON.”

4. Monitor the voltage display on the DVM while

repeatedly touching the CMP sensor signal circuit

at the CMP sensor connector with a test light to

ground.

Does the DVM voltage display switch between 0 and

approximately 5 volts when the test light is touched to

the CMP sensor signal circuit? —Go to

Step 12

Go to

Step 9

91. Ignition “OFF.”

2. Leave the PCM disconnected.

3. Ignition “ON.”

4. Probe the camshaft position signal circuit at the

PCM connector with a test light to B+.

5. If the test light is “ON,” locate and repair the short to

ground in the camshaft position input signal circuit.

Was either circuit shorted to ground? — Verify repair Go to

Step 10

10 1. Ignition “OFF.”

2. Leave the PCM disconnected.

3. Ignition “ON.”

4. Probe the camshaft position signal circuit with a test

light to ground.

5. If the test light is “ON,” locate and repair the short to

voltage in the camshaft position input signal circuit.

Was the test light “ON”? — Verify repair Go to

Step 11

11 1. Ignition “OFF,” disconnect the PCM (leave the CMP

sensor disconnected).

2. Ignition “ON,” check the following circuit:

DThe CMP sensor signal circuit for an open.

3. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair —

12 1. Ignition “ON.”

2. Remove the CMP sensor.

Does the DVM display a voltage near the specified

value? 0 V Go to

Step 14

Go to

Step 13

13 Replace the camshaft position sensor.

Is the action complete? — Verify repair —

14 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0351 Ignition 1 Control Circuit

060RY00303

Circuit Description

The powertrain control module’s (PCM) control circuit 1

provides a zero-volt or a 5-volt output signal to the ignition

coil. The normal voltage on the circuit is zero volts. When

the ignition coil receives the 5-volt signal from the PCM, it

provides a ground path for the B+ supply to the primary

side of the number 1 ignition coil. When the PCM shuts off

the 5 volts to the ignition coil, the ignition coil turns “OFF.”

This causes the ignition coil primary magnetic field to

collapse, producing a voltage in the secondary coil which

fires the spark plug.

The circuit between the PCM and ignition coil is monitored

for an open circuit, short to voltage, and short to ground.

When the PCM detects a problem on ignition control

circuit 1, it will set a DTC P0351.

Conditions for Setting the DTC

DThe ignition is “ON.”

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe output voltage is not equal to 5 volts when output

is “ON.”

DThe output voltage is not equal to 0 volts when output

is “OFF.”

DTwenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle in which the diagnostic has been

run and the fault condition is no longer present.

DA history DTC P0351 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0351 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper mating,

broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Tech 2 display related to DTC P0351 while moving the

connector and wiring related to the ignition system. A

change in the display will indicate the location of the

fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0351 – Ignition 1 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “DTC” information for

DTC P0351 until the DTC P0351 test runs.

5. Note the test result.

Does the T ech 2 indicate DTC P0351 failed this ignition

cycle? — Go to

Step 3

Go to

Diagnostic

Aids

3Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to

Step 4

4Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to

Step 5

51. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 1 at the PCM

with a DVM.

Is the voltage near the specified value? 25-55 mV Go to

Step 6

Go to

Step 9

61. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM for

the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to

Step 7

Go to

Step 13

71. Ignition “OFF.”

2. Disconnect the 3-pin connector at the ignition coil.

3. Check ignition control circuit 1 voltage at the ignition

coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to

Step 8

Go to

Step 11

8Replace the ignition coil.

Is the action complete? — Verify repair —

91. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 1 for short to ground.

Was a problem found? — Verify repair Go to

Step 10

10 Check ignition control circuit 1 for short to voltage.

Was a problem found? — Verify repair Go to

Step 13

11 Check for an open ignition control circuit 1.

Was the ignition control circuit open? —Go to

Step 12

Go to

Step 13

12 Repair the open ignition control circuit.

Is the action complete? — Verify repair —

13 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0352 Ignition 2 Control Circuit

060RY00303

Circuit Description

The powertrain control module’s (PCM) control circuit 2

provides a zero-volt or a 5-volt output signal to the ignition

coil. The normal voltage on the circuit is zero volts. When

the ignition coil receives the 5-volt signal from the PCM, it

provides a ground path for the B+ supply to the primary

side of the number 2 ignition coil. When the PCM shuts off

the 5 volts to the ignition coil, the ignition coil turns “OFF.”

This causes the ignition coil primary magnetic field to

collapse, producing a voltage in the secondary coil which

fires the spark plug.

The circuit between the PCM and ignition coil is monitored

for an open circuit, short to voltage, and short to ground.

When the PCM detects a problem on ignition control

circuit 2, it will set a DTC P0352.

Conditions for Setting the DTC

DThe ignition is “ON.”

DThe engine is turning, determined by the 58 X

crankshaft position input signal.

DThe output voltage is not equal to 5 volts when output

is “ON.”

DThe output voltage is not equal to 0 volts when output

is “OFF.”

DTwenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle in which the diagnostic has been

run and the fault condition is no longer present.

DA history DTC P0352 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0352 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper mating,

broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Tech 2 display related to DTC P0352 while moving the

connector and wiring related to the ignition system. A

change in the display will indicate the location of the

fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0352 – Ignition 2 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “DTC” information for

DTC P0352 until the DTC P0352 test runs.

5. Note the test result.

Does the T ech 2 indicate DTC P0352 failed this ignition

cycle? — Go to

Step 3

Go to

Diagnostic

Aids

3Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to

Step 4

4Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to

Step 5

51. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 2 at the PCM

with a DVM .

Is the voltage near the specified value? 25-55 mV Go to

Step 6

Go to

Step 9

61. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM for

the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to

Step 7

Go to

Step 13

71. Ignition “OFF.”

2. Disconnect the 3-pin connector at the ignition coil.

3. Check ignition control circuit 2 voltage at the ignition

coil connector while cranking the engine connector .

Does the voltage measure between the specified

values? 200-1200 mV Go to

Step 8

Go to

Step 11

8Replace the ignition coil.

Is the action complete? — Verify repair —

91. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 2 for short to ground.

Was a problem found? — Verify repair Go to

Step 10

10 Check ignition control circuit 2 for short to voltage.

Was a problem found? — Verify repair Go to

Step 13

11 Check for an open ignition control circuit 2.

Was the ignition control circuit open? —Go to

Step 12

Go to

Step 13

12 Repair the open ignition control circuit.

Is the action complete? — Verify repair —

13 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0353 Ignition 3 Control Circuit

060RY00303

Circuit Description

The powertrain control module’s (PCM) control circuit 3

provides a zero-volt or a 5-volt output signal to the ignition

coil. The normal voltage on the circuit is zero volts. When

the ignition coil receives the 5-volt signal from the PCM, it

provides a ground path for the B+ supply to the primary

side of the number 3 ignition coil. When the PCM shuts off

the 5 volts to the ignition coil, the ignition coil turns “OFF.”

This causes the ignition coil primary magnetic field to

collapse, producing a voltage in the secondary coil which

fires the spark plug.

The circuit between the PCM and ignition coil is monitored

for an open circuit, short to voltage, and short to ground.

When the PCM detects a problem on ignition control

circuit 3, it will set a DTC P0353.

Conditions for Setting the DTC

DThe ignition is “ON.”

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe output voltage is not equal to 5 volts when output

is “ON.”

DThe output voltage is not equal to 0 volts when output

is “OFF.”

DTwenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle in which the diagnostic has been

run and the fault condition is no longer present.

DA history DTC P0353 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0353 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper mating,

broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Tech 2 display related to DTC P0353 while moving the

connector and wiring related to the ignition system. A

change in the display will indicate the location of the

fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0353 – Ignition 3 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “DTC” information for

DTC P0353 until the DTC P0353 test runs.

5. Note the test result.

Does the T ech 2 indicate DTC P0353 failed this ignition

cycle? — Go to

Step 3

Go to

Diagnostic

Aids

3Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to

Step 4

4Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to

Step 5

51. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 3 at the PCM

with a DVM.

Is the voltage near the specified value? 25-55 mV Go to

Step 6

Go to

Step 9

61. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM for

the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to

Step 7

Go to

Step 13

71. Ignition “OFF.”

2. Disconnect the 3-pin connector at the ignition coil.

3. Check ignition control circuit 3 voltage at the ignition

coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to

Step 8

Go to

Step 11

8Replace the ignition coil.

Is the action complete? — Verify repair —

91. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 3 for short to ground.

Was a problem found? — Verify repair Go to

Step 10

10 Check ignition control circuit 3 for short to voltage.

Was a problem found? — Verify repair Go to

Step 13

11 Check for an open ignition control circuit 3.

Was the ignition control circuit open? —Go to

Step 12

Go to

Step 13

12 Repair the open ignition control circuit.

Is the action complete? — Verify repair —

13 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0354 Ignition 4 Control Circuit

060RY00303

Circuit Description

The powertrain control module’s (PCM) control circuit 4

provides a zero-volt or a 5-volt output signal to the ignition

coil. The normal voltage on the circuit is zero volts. When

the ignition coil receives the 5-volt signal from the PCM, it

provides a ground path for the B+ supply to the primary

side of the number 4 ignition coil. When the PCM shuts off

the 5 volts to the ignition coil, the ignition coil turns “OFF.”

This causes the ignition coil primary magnetic field to

collapse, producing a voltage in the secondary coil which

fires the spark plug.

The circuit between the PCM and ignition coil is monitored

for an open circuit, short to voltage, and short to ground.

When the PCM detects a problem on ignition control

circuit 4, it will set a DTC P0354.

Conditions for Setting the DTC

DThe ignition is “ON.”

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe output voltage is not equal to 5 volts when output

is “ON.”

DThe output voltage is not equal to 0 volts when output

is “OFF.”

DTwenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle in which the diagnostic has been

run and the fault condition is no longer present.

DA history DTC P0354 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0354 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper mating,

broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Tech 2 display related to DTC P0354 while moving the

connector and wiring related to the ignition system. A

change in the display will indicate the location of the

fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0354 – Ignition 4 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “DTC” information for

DTC P0354 until the DTC P0354 test runs.

5. Note the test result.

Does the T ech 2 indicate DTC P0354 failed this ignition

cycle? — Go to

Step 3

Go to

Diagnostic

Aids

3Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to

Step 4

4Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to

Step 5

51. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 4 at the PCM

with a DVM.

Is the voltage near the specified value? 25-55 mV Go to

Step 6

Go to

Step 9

61. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM for

the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to

Step 7

Go to

Step 13

71. Ignition “OFF.”

2. Disconnect the 3-pin connector at the ignition coil.

3. Check ignition control circuit 4 voltage at the ignition

coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to

Step 8

Go to

Step 11

8Replace the ignition coil.

Is the action complete? — Verify repair —

91. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 4 for short to ground.

Was a problem found? — Verify repair Go to

Step 10

10 Check ignition control circuit 4 for short to voltage.

Was a problem found? — Verify repair Go to

Step 13

11 Check for an open ignition control circuit 4.

Was the ignition control circuit open? —Go to

Step 12

Go to

Step 13

12 Repair the open in ignition control circuit.

Is the action complete? — Verify repair —

13 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0355 Ignition 5 Control Circuit

060RY00303

Circuit Description

The powertrain control module’s (PCM) control circuit 5

provides a zero-volt or a 5-volt output signal to the ignition

coil. The normal voltage on the circuit is zero volts. When

the ignition coil receives the 5-volt signal from the PCM, it

provides a ground path for the B+ supply to the primary

side of the number 5 ignition coil. When the PCM shuts off

the 5 volts to the ignition coil, the ignition coil turns “OFF.”

This causes the ignition coil primary magnetic field to

collapse, producing a voltage in the secondary coil which

fires the spark plug.

The circuit between the PCM and ignition coil is monitored

for an open circuit, short to voltage, and short to ground.

When the PCM detects a problem on ignition control

circuit 5, it will set a DTC P0355.

Conditions for Setting the DTC

DThe ignition is “ON.”

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe output voltage is not equal to 5 volts when output

is “ON.”

DThe output voltage is not equal to 0 volts when output

is “OFF.”

DTwenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle in which the diagnostic has been

run and the fault condition is no longer present.

DA history DTC P0355 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0355 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper mating,

broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Tech 2 display related to DTC P0355 while moving the

connector and wiring related to the ignition system. A

change in the display will indicate the location of the

fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0355 – Ignition 5 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “DTC” information for

DTC P0355 until the DTC P0355 test runs.

5. Note the test result.

Does the T ech 2 indicate DTC P0355 failed this ignition

cycle? — Go to

Step 3

Go to

Diagnostic

Aids

3Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to

Step 4

4Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to

Step 5

51. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 5 at the PCM

with a DVM.

Is the voltage near the specified value? 25-55 mV Go to

Step 6

Go to

Step 9

61. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM for

the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to

Step 7

Go to

Step 13

71. Ignition “OFF.”

2. Disconnect the 3-pin connector at the ignition coil.

3. Check ignition control circuit 5 voltage at the ignition

coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to

Step 8

Go to

Step 11

8Replace the ignition coil.

Is the action complete? — Verify repair —

91. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 5 for short to ground.

Was a problem found? — Verify repair Go to

Step 10

10 Check ignition control circuit 5 for short to voltage.

Was a problem found? — Verify repair Go to

Step 13

11 Check for an open ignition control circuit 5.

Was the ignition control circuit open? —Go to

Step 12

Go to

Step 13

12 Repair the open ignition control circuit.

Is the action complete? — Verify repair —

13 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0356 Ignition 6 Control Circuit

060RY00303

Circuit Description

The powertrain control module’s (PCM) control circuit 6

provides a zero-volt or a 5-volt output signal to the ignition

coil. The normal voltage on the circuit is zero volts. When

the ignition coil receives the 5-volt signal from the PCM, it

provides a ground path for the B+ supply to the primary

side of the number 6 ignition coil. When the PCM shuts off

the 5 volts to the ignition coil, the ignition coil turns “OFF.”

This causes the ignition coil primary magnetic field to

collapse, producing a voltage in the secondary coil which

fires the spark plug.

The circuit between the PCM and ignition coil is monitored

for an open circuit, short to voltage, and short to ground.

When the PCM detects a problem on ignition control

circuit 6, it will set a DTC P0356.

Conditions for Setting the DTC

DThe ignition is “ON.”

DThe engine is turning, determined by the 58X

crankshaft position input signal.

DThe output voltage is not equal to 5 volts when output

is “ON.”

DThe output voltage is not equal to 0 volts when output

is “OFF.”

DTwenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle in which the diagnostic has been

run and the fault condition is no longer present.

DA history DTC P0356 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P0356 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper mating,

broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

DDamaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe the

Tech 2 display related to DTC P0356 while moving the

connector and wiring related to the ignition system. A

change in the display will indicate the location of the

fault.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P0356 – Ignition 6 Control Circuit

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “DTC” information for

DTC P0356 until the DTC P0356 test runs.

5. Note the test result.

Does the T ech 2 indicate DTC P0356 failed this ignition

cycle? — Go to

Step 3

Go to

Diagnostic

Aids

3Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to

Step 4

4Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to

Step 5

51. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 6 at the PCM

with a DVM.

Is the voltage near the specified value? 25-55 mV Go to

Step 6

Go to

Step 9

61. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM for

the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to

Step 7

Go to

Step 13

71. Ignition “OFF.”

2. Disconnect the 3-pin connector at the ignition coil.

3. Check ignition control circuit 6 voltage at the ignition

coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to

Step 8

Go to

Step 11

8Replace the ignition coil.

Is the action complete? — Verify repair —

91. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 6 for short to ground.

Was a problem found? — Verify repair Go to

Step 10

10 Check ignition control circuit 6 for short to voltage.

Was a problem found? — Verify repair Go to

Step 13

11 Check for an open ignition control circuit 6.

Was the ignition control circuit open? —Go to

Step 12

Go to

Step 13

12 Repair the open ignition control circuit.

Is the action complete? — Verify repair —

13 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0404 EGR Open Stuck

D06RW055

Circuit Description

The powertrain control module (PCM) monitors the EGR

valve pintle position input to ensure that the valve

responds properly to commands from the PCM, and to

detect a fault if pintle position is different from

commanded position. If the PCM detects a pintle position

signal indicates more than 15 points different between

current and commanded and more than 15 seconds, the

PCM will set DTC P0404.

Conditions for Setting the DTC

DIgnition voltage is between 11 and 16 volts.

DIntake Air temp is more than 3°C.

DDesire EGR position is more than 0.

DThe difference between desired EGR and current EGR

is less than 3%.

DDifference EGR pintle position between current and

commanded position becomes more than 15% and

last more than 15 seconds, and this condition meets

three times in a trip. Then it trigger , the PCM lights on.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) as soon as failure detected after consecutive 2nd

trip in which the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in Failure

Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0404 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0404 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DExcessive carbon deposit on EGR valve shaft may

cause EGR stuck open or unsmooth operation. Those

carbon deposit may occur by unusual port operation.

Clean up carbon may make smooth function of EGR

valve.

DPoor connection or damaged harness – Inspect the

wiring harness for damage. If the harness appears to

be OK, observe the EGR actual position display on the

Tech 2 while moving connectors and wiring harnesses

related to EGR valve. A change in the display will

indicate the location of the fault.

DTC P0404 – EGR Open Stuck

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0404

until the DTC P0404 test runs. Note the result.

Does the Tech 2 indicates DTC P0404 failed this

ignition? — Go to

Step 3

Refer to

Diagnostic

Aids

31. Disconnect the EGR valve harness connector.

2. Inspect the EGR valve and connectors for damaged

pin or terminals.

Were there any damaged pins or terminals? —Go to

Step 4

Go to

Step 5

4Repair the damaged pin or terminal. — Verify repair Is the action

complete?

51. Remove EGR valve from Engine.

2. Inspect EGR valve whether there is any excessive

carbon deposit on EGR shaft.

Was excessive carbon deposit on EGR valve shaft? —Go to

Step 6

Go to

Step 7

61. Clean up EGR valve shaft and inside of EGR valve.

2. Visually inspect damage of pintle and seat if is bent,

leakage may occur.

W as there any severe damage which affects function? — Go to

Step 8

Verify repair

Go to

Step 7

7 1. Reconnect.

2. Ignition “OFF”.

3. Install the Tech 2.

4. Run the engine at idle.

5. On the Tech 2, select EGR control test.

6. Use the “UP” arrow to increase the EGR from 0% to

40%.

Did EGR work properly? — — Go to

Step 8

8Replace the EGR valve.

Does DTC P0404 still fail “DTC” test on the Tech 2? —Go to

Step 9

Verify repair

9Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0405 EGR Low Voltage

D06RW055

Circuit Description

The powertrain control module (PCM) monitors the EGR

valve pintle position input to ensure that the valve

responds properly to command from the PCM. If current

pintle position voltage indicates less than 0.1 V and last

more than 10 seconds, then the PCM will set DTC P0405.

Conditions for Setting the DTC

DIgnition voltage is between 11 and 16 volts.

DEGR pintle position output voltage is less than 0.1 volt

and last more than 10 sec. Action taken when the DTC

sets.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) as soon as failure detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in Failure

Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0405 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0405 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection or damaged harness – Inspect the

wiring harness for damage. If the harness appears to

be OK, observe the EGR actual position display on the

Tech 2 while moving connectors and wiring harnesses

related to EGR valve. A change in the display will

indicate the location of the fault.

DTC P0405 – EGR Low Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0405

until the DTC P0405 test runs. Note the result.

Does the Tech 2 indicates DTC P0405 failed this

ignition? — Go to

Step 3

Refer to

Diagnostic

Aids

31. Disconnect the EGR valve harness connector.

2. Inspect the EGR valve and connectors for damaged

pin or terminals.

Were there any damaged pins or terminals? —Go to

Step 4

Go to

Step 5

4Repair the damaged pin or terminal.

Is the action complete? — Verify repair —

51. Disconnect the EGR harness connector.

2. Ignition “ON”.

3. At the EGR valve, use a DVM to check the voltage

at the 5 volt reference wire (RED) and ground (B).

Did the DVM indicate the specified value? 4–6 V Go to

Step 6

Go to

Step 7

61. Disconnect the EGR harness connector.

2. Measure resistance between terminal B and D.

Was resistance in range? 5–5.5 KWGo to

Step 10

Go to

Step 17

71. Ignition “ON”.

2. At the PCM connector, backprove with a DVM at the

5 volt reference for the EGR valve.

Did the DVM indicate the specified value? 4–6 V Go to

Step 8

Go to

Step 18

8Repair the open 5 volt reference circuit.

Is the action complete? — Verify repair —

9Repair the damaged sensor ground wire.

Is the action complete? — Verify repair —

10 1. Disconnect the EGR harness

2. Use an ohmmeter to measure between the pintle

position pin and the sensor ground pin on the EGR

valve.

NOTE: J-35616 Connector Test Adapter Kit may be

useful for gaining access to the recessed pins on the

valve.

W as the ohmmeter reading approximately equal to the

specified value? 1 to 1.25 KWGo to

Step 13

Go to

Step 17

11 1. Ignition “ON”.

2. Backprobe with a DVM to measure voltage at EGR

valve pintle position pin and sensor ground pin.

Was voltage in range? Less than 0.1

VGo to

Step 17

Go to

Step 12

Step NoYesValue(s)Action

12 1. Ignition “ON”.

2. Backprobe with a DVM to measure voltage at PCM

sensor ground pin and pintle position pin.

Was voltage in range? Less than 0.1

VGo to

Step 13

Go to

Step 18

13 1. Ignition “OFF”.

2. Disconnect the EGR harness.

3. Check short circuit between EGR pintle position

circuit and EGR ground circuit.

Was any short circuit? —Go to

Step 14

Go to

Step 18

14 Locate and repair the short to ground in the pintle

position circuit

Is the action complete? — Verify repair —

15 1. Ignition “OFF”.

2. Disconnect the PCM.

3. Ignition “ON”.

4. Measure the voltage between the EGR pintle

position circuit and ground.

Is the measured voltage near the specified value? Less than 0.1

VGo to

Step 17

Go to

Step 16

16 Check for a short circuit between other wires and the

pintle position circuit

Is there any short circuit? —

Repair short

circuit

Verify repair Go to

Step 17

17 Replace the EGR valve.

Does DTC P1404 still fail “DTC test on the Tech 2? —Go to

Step 18

Verify repair

18 Examine the PCM pin and terminal connection.

Was there a damaged terminal? —Go to

Step 4

Go to

Step 19

19 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0406 EGR High Voltage

D06RW055

Circuit Description

The powertrain control module (PCM) monitors the EGR

valve pintle position input to ensure that the valve

responds properly to command from the PCM. If current

pintle position voltage indicates more than 4.8 V and last

more than 10 seconds, then the PCM will set DTC P0406.

Conditions for Setting the DTC

DIgnition voltage is between 11 and 16 volts.

DEGR pintle position output voltage is more than 4.8 volt

and last more than 10 sec.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) as soon as failure detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in Failure

Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0406 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0406 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection or damaged harness – Inspect the

wiring harness for damage. If the harness appears to

be OK, observe the EGR actual position display on the

Tech 2 while moving connectors and wiring harnesses

related to EGR valve. A change in the display will

indicate the location of the fault.

DTC P0406 – EGR High Voltage

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0406

until the DTC P0406 test runs. Note the result.

Does the Tech 2 indicates DTC P0406 failed this

ignition? — Go to

Step 3

Refer to

Diagnostic

Aids

31. Disconnect the EGR valve harness connector.

2. Inspect the EGR valve and connectors for damaged

pin or terminals.

Were there any damaged pins or terminals? —Go to

Step 4

Go to

Step 5

4Repair the damaged pin or terminal.

Is the action complete? — Verify repair Is the action

complete?

51. Disconnect the EGR harness connector.

2. Ignition “ON”.

3. At the EGR valve, use a DVM to check the voltage

at the 5 volt reference wire (RED).

Did the DVM indicate the specified value? 4–6 V Go to

Step 8

Go to

Step 6

61. Ignition “ON”.

2. At the PCM connector, backprove with a DVM at the

5 volt reference for the EGR valve.

Did the DVM indicare the specified value? 4–6 V Go to

Step 7

Go to

Step 16

7Repair the open 5 volt reference circuit

Is the action complete? — Verify repair —

81. Ignition “OFF”

2. Disconnect the EGR harness.

3. Use a DVM to check for an resistance between D (5

V reference) and B (Sensor Ground) at EGR sensor

terminals.

NOTE: J-35616 Connector Test Adapter Kit may be

useful for gaining access to the recessed pins on the

valve.

Was the measured resistance in range? 5 to 5 KWGo to

Step 9

Go to

Step 15

9 1. Ignition “OFF”.

2. Disconnect the EGR harness.

3. Use a DVM to check for an resistance between B

and C at EGR sensor terminal.

Is there an open circuit? —Go to

Step 15

Go to

Step 10

10 1. Ignition “OFF”.

2. Disconnect the EGR harness at PCM connector.

3. Use a DVM to check for shorted wire between A1

and B7.

Is there a shorted wire? —Go to

Step 14

Go to

Step 11

Step NoYesValue(s)Action

11 1. Ignition “ON”.

2. Use a DVM to backprove at terminal C of EGR

valve for voltage.

Was measured voltage more than 4.8 V? more than 4.8

VGo to

Step 12

Go to

Step 12

12 1. Ignition “ON”.

2. Stay the EGR harness connected.

3. Check voltage by backproving at PCM B7 terminal.

Was voltage more than 4.8 V? 4.8 V Go to

Step 16

Go to

Step 13

13 1. Locate short circuit at EGR harness between RED

to RED or GREEN, RED to YEL.

2. Replace EGR harness.

Is the action complete? — Verify repair —

14 Replace EGR harness.

Is the action complete? — Verify repair —

15 Replace the EGR valve.

Does DTC P1404 still fail “DTC test on the Tech 2? —Go to

Step 16

Verify repair

16 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0502 VSS Circuit Low Input

D06RX021

Circuit Description

The vehicle speed sensor has a magnet rotated by the

transmission output shaft. Attached to the sensor is a hall

effect circuit the interacts with the magnetic field treated

by the rotating magnet. A 12-volt operating supply for the

speed sensor hall circuit is supplied from the meter fuse.

The VSS pulses to ground the 9-volt signal sent from the

powertrain control module (PCM) on the reference circuit.

The PCM interprets vehicle speed by the number of

pulses to ground per second on the reference circuit.

Conditions for Setting the DTC

DEngine is running.

DEngine coolant temperature is above 60°C (140°F).

DEngine speed is between 1800 RPM and 2500 RPM.

DThrottle angle is between 10% and 40%.

DEngine load is greater than 50 kPa.

DMAP sensor indicates greater than 50 kPa manifold

pressure.

DPCM detects no VSS signal for 12.5 seconds over a

period of 25 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first time the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0502 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0502 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

9. To avoid backprobing the VSS and possibly

damaging a seal or terminal, the VSS output can be

tested at the point where the transmission harness

connected to the engine harness. The green 16-way

connector is adjacent to a blue 16-way connector,

and it can be easily accessed by removing the air

cleaner assembly. The green 16-way connector is

separated, and battery voltage is applied to the VSS

through the yellow wire at one corner of the

connector. The VSS output can be monitored with a

DVM connected to the blue wire with a black tracer.

The two wires are next to each other in the 16-way

connector . The test connections are made on the

transmission side of the connector, the side that is

not clipped to the body sheetmetal.

14. The speedometer-to-PCM VSS signal wire is

spliced to a wire leading to the cruise control

module. If a short to ground or voltage is found

between the PCM and speedometer, it could be

located between the splice and the cruise control

module.

DTC P0502 –VSS Circuit Low Input

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Does the speedometer work? —Go to

Step 10

Go to

Step 3

31. Disconnect the VSS connector.

2. Ignition “ON.”

3. Using a test light to battery +, probe the connector

ground wire.

Did the light illuminate? —Go to

Step 5

Go to

Step 4

4Repair the sensor ground.

Is the action complete? — Verify repair —

51. Ignition “ON,” sensor disconnected.

2. Using a DVM, measure at the VSS connector

between ground and voltage supply.

Was the measurement near the specified value? Battery

voltage Go to

Step 7

Go to

Step 6

6Repair the open or short to ground which may have

blown the meter fuse.

Is the action complete? — Verify repair —

71. Ignition “ON,” VSS disconnected.

2. Using a DVM, measure at the VSS connector

between ground and the blue/black wire from the

speedometer.

Was the measurement near the specified value? 7.5-8 V Go to

Step 9

Go to

Step 8

8Check for an open or short circuit between the

speedometer and the VSS.

Was an open or short circuit located? — Verify repair Go to

Step 9

9Replace the speedometer.

Is the action complete? — Verify repair —

Step NoYesValue(s)Action

10 1. Ignition “OFF.”

2. Disconnect the MAF sensor. The connector

attaches the VSS wires from the transmission

harness to the left-side engine harness.

3. Disconnect the green 16-way connector.

4. Select a terminal adapter from kit 5-8840-0385-0

that can be used with a jumper to supply B+ to the

yellow (transmission side of the connector). There

are 2 yellow wires at that connector , but the correct

one is in the corner position.

5. Use another terminal adapter to attach a voltmeter

to the blue wire with a black tracer (next to the wire in

the previous step.)

6. At the transmission side of the green 16-way

connector, locate the black wire next to the VSS

yellow ign+ wire. The black wire is the VSS ground

wire. Use a terminal adapter to attach a jumper to

ground to the black VSS ground wire at the

transmission side of the connector.

7. Raise the rear wheels off the ground with

transmission in neutral.

Does the DVM toggle back and forth between 0.6 V and

10 V as the wheels (and driveshaft) are rotated? —Go to

Step 12

Go to

Step 11

11 Replace the VSS.

Is the action complete? — Verify repair —

12 Check for an open or short between the PCM and the

speedometer.

Was a problem found? — Verify repair Go to

Step 13

13 Replace the PCM.

Is the action complete? — Verify repair —

Diagnositc Troule Code (DTC) P0562 System Voltage Low

D06RX022

Circuit Description

The powertrain control module (PCM) monitors the

system voltage on the ignition feed terminal to the PCM.

A system voltage DTC will set whenever the voltage is

below a calibrated value.

Conditions for Setting the DTC

DIgnition “ON.”

DSystem voltage is below 11.5 volts for 15 minutes.

Action Taken When the DTC Sets

DThe PCM will not illuminate the malfunction indicator

lamp (MIL).

DThe PCM will store as Failure Records conditions

which were present when the DTC was set. This

information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

DA history DTC P0562 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0562 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

If the DTC sets when an accessory is operated, check for

a poor connection or excessive current draw.

DTC P0562 – System Voltage Low

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Using a DVM, measure the battery voltage at the

battery.

Is the battery voltage greater than the specified value? 11.5 V Go to

Step 3

Charge

battery, then

go to

Step 3

31. Install a Tech 2.

2. Select “Ignition Volts” on the Tech 2.

3. Start the engine and raise the engine speed to the

specified value.

4. Load the electrical system by turning on the

headlights, high blower, etc.

Is the ignition voltage approximately equal to the

specified value? 2000 RPM

12.8-14.1 V Go to

Step 4

Go to

Starting/Char

ging

41. Ignition “OFF.”

2. Disconnect the PCM connector at the PCM.

3. Using a DVM, measure the battery voltage at the

PCM connector A-4.

Is it approximately equal to battery voltage? —

Check for

excessive

current draw

with ignition

“OFF,” engine

“OFF.” Go to

Step 5

51. Check for faulty connections at the PCM harness

terminals.

2. Repair as necessary.

Was a repair necessary? — Verify repair Go to

Step 6

6Check for an open battery feed circuit to the PCM.

Is the action complete? — Verify repair Go to

Step 7

7Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0563 System Voltage High

Circuit Description

The powertrain control module (PCM) monitors the

system voltage on the ignition feed terminals to the PCM.

A system voltage DTC will set whenever the voltage is

above a calibrated value.

Conditions for Setting the DTC

DIgnition “ON.”

DSystem voltage is above 16 volts for 15 minutes.

Action Taken When the DTC Sets

DThe PCM will not illuminate the malfunction indicator

lamp (MIL).

DThe PCM will store as Failure Records only conditions

which were present when the DTC was set. This

information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

DA history DTC P0563 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0563 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

If the DTC sets when an accessory is operated, check for

a poor connection or defective accessory.

DTC P0563 – System Voltage High

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Using a DVM, measure the battery voltage at the

battery.

Is the battery voltage less than the specified value? 11.5 V Go to

Step 3

Go to

Step 4

31. Charge the battery and clean the battery terminals.

2. Clean the battery ground cable connection if

corrosion is indicated.

Is the battery voltage less than the specified value? 11.5 V Replace

battery Go to

Step 4

41. Turn “OFF” all the accessories.

2. Install a Tech 2.

3. Select the ignition voltage parameter on the Tech 2.

4. Start the engine and raise the engine RPM to the

specified value.

Is the voltage more than 2.5 volts greater than the

measurement taken in step 2 or 3? 2000 RPM

Go to

Starting/Char

ging

Go to

Step 5

5Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0601 PCM Memory

Circuit Description

The powertrain control module (PCM) used in this vehicle

utilizes an electrically erasable programmable read-only

memory (EEPROM). The EEPROM contains program

information and the calibrations required for engine,

transmission, and powertrain diagnostics operation.

Unlike the PROM used in past applications, the EEPROM

is not replaceable.

Conditions for Setting the DTC

DThe PCM detects an internal program fault (check sum

error).

Action Taken When the DTC Sets

DThe PCM will not illuminate the malfunction indicator

lamp (MIL).

DThe PCM will store conditions which were present

when the DTC was set in the Failure Records data only.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P0601 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P0601 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

DTC P0601 – PCM Memory

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1171 Fuel System Lean Dueing Acceleration

D06RX141

Circuit Description

The powertrain control module (PCM) internal circuitry

can identify if the vehicle fuel system is capable of

supplying adequate amounts of fuel during heavy

acceleration (power enrichment). The PCM monitors the

voltage of the oxygen sensor during power enrichment.

When a power enrichment mode of operation is

requested during “closed loop” operation (by heavy

acceleration), the PCM will provide more fuel to the

engine. Under these conditions the PCM should detect a

“rich” condition (high oxygen sensor voltage). If this “rich”

exhaust is not detected at this time, a DTC P1 171 will set.

A plugged fuel filter, restricted fuel line, restricted in-tank

filter or defective fuel pump can prevent adequate amouts

of fuel from being supplied during power enrichment

mode.

Conditions for Setting the DTC

DNo related DTCs.

DEngine is operating in “closed loop power enrichment”

mode for 3 seconds.

DEngine coolant temperature is above 60°C (140°F).

DWhile in “power enrichment” mode the oxygen sensor

voltage remains below 400 mV for 3 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) the first the fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P1171 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P1171 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

DA restricted fuel filter or fuel line, restricted in-tank filter,

or a defective fuel pomp may supply adequate

amounts of fuel at idle, but may not be able to supply

enough fuel during heavy acceleration.

DWater or alcohol in the fuel may cause low HO2S

voltage during acceleration.

DCheck for faulty or plugged fuel injector(s).

DCheck for low fuel.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

4. When the engine is idling or at steady cruise, the

HO2S voltage should vary from between

approximately 100 mV to 900 mV. It is possible to

measure a satisfactory fuel pressure at idle even

though the pressure may drop at high flow

requirements. It may be necessary to watch fuel

pressure at high engine load.

5. Wrap a shop towel around the fuel pressure

connector to absorb any small amount of fuel

leakage that may occur when installing gauge.

Ignition “ON,” pump pressure should be

280-320kPa.

7. Add Caution: Use correct pliers so damage to fuel

lines will not occur.

DTC P1171 – Fuel System Lean During Acceleration

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Are any component-related DTCs set?

—

Go to

component

DTC charts Go to

Step 3

31. Check the vehicle’s fuel tank for an adequate

amount of fuel.

2. Add fuel to the vehicle’s fuel tank if the tank is almost

empty.

Was fuel added to the vehicle’s fuel tank? —Go to

Step 4

Go to

Step 5

41. Place the transmission in park.

2. Using a Tech 2, observe HO2S 1 voltage while

running warm engine 75°C-95°C (167°F-203°F) at

1200 RPM.

3. HO2S 1 voltage should vary within the specified

range.

4. Quickly open the throttle halfway for a few seconds.

Did the voltage suddenly rise toward the high end of the

specified range? 100-900 mV

Go to

Fuel

System

Diagnosis

Go to

Step 5

51. Disconnect the fuel pump relay and crank the

engine to relieve the fuel pressure.

2. Install the fuel pressure gauge.

3. Start the engine and idle at normal operating

temperature.

4. Disconnect the vacuum line going to the fuel

pressure regulator.

With the engine running, is the fuel pressure within the

specified range? 280-325 kPa

(41-46 psi)

Go to

OBD

System

Check

Go to

Step 6

6Check for restricted fuel lines or restricted in-line filter.

Was a problem found? — Verify repair Go to

Step 7

71. Ignition “OFF.”

2. Remove the fuel pump relay and replace it with a

fused jumper which will connect the relay’s battery

terminal to the terminal leading to the fuel pump

fuse.

3. While the fuel pump is operating, use pliers to slowly

close the return line (do not exceed the first

specified value).

Using the pliers to restrict the return line, can the fuel

pressure be manipulated to exceed the second

specified value?

414 kPa (60

psi) 325 kPa

(46 psi)

Go to

Diagnostic

Aids

Go to

Step 8

8Check for:

DFaulty fuel pump

DRestricted fuel pump strainer (sock)

DIncorrect fuel pump

DIncorrect fuel being used

DHot fuel

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1380 ABS Rough Road ABS System Fault

Circuit Description

The powertrain control module (PCM) monitors ABS fault

signal. When PCM receives fault signal, PCM will set

DTC P1380.

Conditions for Setting the DTC

DVehicle speed is more than 5 mph.

DLoad is less than 99%.

DEngine revolution is less than 6250 rpm.

DPCM receives ABS fault signals from ABS unit.

DIgnition on.

DMisfire DTCs exist.

D100 test failures within 120 test samples.

Action Taken When the DTC Sets

DThe PCM will store DTC 1380 only, no MIL turn on.

Conditions for Clearing the MIL/DTC

DA history DTC P1380 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC 1380 can be cleared by using Tech-II or

disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

DPCM and ABS communication line short circuit to other

line may cause faulty signal. Inspect communication

line.

DFollow ABS ECU diagnosis procedure, refer to ABS

procedure page.

DTC P1380 – ABS Rough Road ABS System Fault

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P1380.

Note the result.

Does the Tech 2 indicates DTC P1380 DTCs failed this

ignition? —

Refer to ABS

diagnosis

After inspecting

ABS, repeat

Step 2

If problem still

exists, go to

Step 3

Clear DTC by

Tech 2

3Check short circuit among communication line of

PCM/ABS and others.

Does short circuit exist? —Repair wiring

Verify repair Go to

Step 4

4Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1381 ABS Rough Road Class 2 Serial Link

Error

Circuit Description

The powertrain control module (PCM) monitors no ABS

signal. When PCM does not receive ABS signal, PCM will

set DTC P1381.

Conditions for Setting the DTC

DPCM does not receive ABS signals from ABS ECU.

DVehicle speed is more than 0 mph.

DLoad is less than 99%.

DEngine revolution is less than 6250rpm.

D2.5 second after key on.

DMisfire DTCs exist.

D100 test failures within 120 test samples.

Action Taken When the DTC Sets

DThe PCM will store DTC 1381 only, MIL on.

Conditions for Clearing the MIL/DTC

DA history code DTC P1381 will clear after 40

consecutive warm-up cycles have occurred without a

fault.

DDTC P1381 can be cleared by Tech-II or by

disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

DInspect open circuit of communication wire between

ABS ECU and PCM.

DFollow ABS ECU diagnosis procedure.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P1381 – ABS Rough Road Class 2 Serial Link Error

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC inf. for DTC P1381.

Note the result.

Does the Tech 2 indicates DTC P1381 DTCs failed this

ignition? —

Refer to ABS

diagnosis

After inspecting

ABS, repeat

Step 2

If problem still

exists, go to

Step 3

Clear DTC by

Tech 2

3Check open circuit among communication line of

PCM/ABS and others.

Does short circuit exist? —Repair wiring

Verify repair Go to

Step 4

4Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1404 EGR Stuck Closed

D06RW055

Circuit Description

The powertrain control module (PCM) monitors the EGR

valve pintle position input to ensure that the valve

responds properly to commands from the PCM, and to

detect a fault if current pintle zero position is different from

the learned zero position. If the PCM detects a pintle

position signal indicates more than 30 % different

between current zero position and the learned zero

position for more than 5 seconds, and this condition exists

3 times during trip, then the PCM will set DTC P1404.

Conditions for Setting the DTC

DIgnition voltage is between 11 and 16 volts.

DIntake Air temp is more than 3°C.

DDesired EGR position is 0.

DDifference of EGR pintle position between current and

the learned zero is more than 30 % for more than 5

seconds, and exists three time to the above condition

during a trip the PCM will set DTC 1404. Then it trigger

the PCM lights on.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after consecutive 2nd trip in which the fault is

detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in Failure

Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P1404 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P1404 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DExcessive carbon deposit on EGR valve shaft and/or

foreign material may cause the EGR valve not to fully

seated. The carbon deposit may occur by unusual port

operation. Remove foreign material and/or excessive

carbon deposit on EGR valve shaft may allow the EGR

valve to be fully seated.

DPoor connection or damaged harness – Inspect the

wiring harness for damage.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P1404 – EGR Stuck Closed

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Ignition “ON,” engine “OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC inf. for DTC P1404

until the DTC P1404 test runs. Note the result.

Does the Tech 2 indicates DTC P1404 failed this

ignition? — Go to

Step 3

Refer to

Diagnostic

Aids

31. Disconnect the EGR valve harness connector.

2. Inspect the EGR valve and connectors for damaged

pin or terminals.

Were there any damaged pins or terminals? —Go to

Step 4

Go to

Step 5

4Repair the damaged pin or terminal.

Is the action complete? — Verify repair —

51. Remove EGR valve from Engine.

2. Inspect EGR valve for is any excessive carbon

deposit on EGR shaft.

3. Inspect for any foreign material inside of EGR valve.

Was excessive carbon deposit on EGR valve shaft

and/or foreign material in EGR valve ? —Go to

Step 6

Go to

Step 7

61. Clean up EGR valve shaft and inside of EGR valve.

2. Remove foreign material from EGR valve.

3. Visually inspect damage of pintle and seat to see if it

is bent If damaged leakage may occur.

W as there any severe damage which affects function? — Go to

Step 8

Verify repair

Go to

Step 7

71. Install the EGR valve.

2. Ignition “OFF”.

3. Install the Tech 2.

4. Run the engine at idle.

5. On the Tech 2, select EGR control test.

6. Use the “UP” arrow to increase the EGR from 0% to

40%.

Did EGR work properly? — — Go to

Step 8

81. Reset the learned zero EGR valve position.

2. Repeat step 7.

Did EGR work properly? — Verify repair Go to

Step 9

9Replace the EGR valve.

Does DTC P1404 still fail “DTC” test on the Tech 2? —Go to

Step 10

Verify repair

10 Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1508 IAC System Low RPM

T321115

Circuit Description

The powertrain control module (PCM) controls engine

idle speed by adjusting the position of the idle air control

(IAC) motor pintle. The IAC is a bi-directional stepper

motor driven by two coils. The PCM applies current to the

IAC coils in steps (counts) to extend the IAC pintle into a

passage in the throttle body to decrease air flow. The

PCM reverses the current to retract the pintle, increasing

air flow. This method allows highly accurate control of idle

speed and quick response to changes in engine load. If

the PCM detects a condition where too low of an idle

speed is present and the PCM is unable to adjust idle

speed by increasing the IAC counts, DTC P1508 will set,

indicating a problem with the idle control system.

Conditions for Setting the DTC

DNo Tech 2 test is being run.

DNone of these DTCs are set: TP sensor, VSS, ECT,

EGR, fuel system, MAF, MAP, IAT, canister purge,

injector control or ignition control.

DBarometric pressure is above 75 kPa.

DEngine coolant temperature (ECT) is above 50°C

(120°F).

DVehicle speed is less than 1 mph.

DThe engine has been running for at least 125 seconds.

DCanister purge duty cycle is above 10%.

DIgnition voltage is between 9.5 volts and 16.7 volts.

DThe throttle is closed.

DEngine speed is lower than desired idle.

DEngine speed is more than 100-200 RPM lower than

desired idle, based upon coolant temperature.

DAll of the above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P1508 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P1508 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM or IAC motor – Inspect

harness connectors for backed-out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal-to-wire

connection.

DDamaged harness – Inspect the wiring for damage.

DRestricted air intake system – Check for a possible

collapsed air intake duct, restricted air filter element,

or foreign objects blocking the air intake system.

DThrottle body – Check for objects blocking the IAC

passage or throttle bore, excessive deposits in the IAC

passage and on the IAC pintle, and excessive deposits

in the throttle bore and on the throttle plate.

DLarge vacuum leak – Check for a condition that causes

a large vacuum leak, such as an incorrectly installed or

faulty PCV valve or a disconnected brake booster

hose.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P1508 –IAC System Low RPM

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Start the engine.

2. Turn all accessories “OFF”(A/C, rear defroster,

etc).

3. Using a T ech 2, command RPM up to 1500, down to

500, and then up to 1500 while monitoring the

“Engine Speed” on the Tech 2.

NOTE: This T ech 2 command may cause the engine to

“cut out” when RPM goes above 1500. If this occurs,

the “cutting out” will stop when the Tech 2 command for

the test is discontinued, or if the Tech 2 command is

changed to less than 1500 RPM.

Does the “Engine Speed” remain within the specified

value of the “Desired Idle” for each RPM command? ± 50 RPM

No trouble

found. Go to

Diagnostic

Aids

Go to

Step 3

31. Disconnect the IAC.

2. Install IAC Noid Light 5–8840–2312–0 or

equivalent.

3. With the engine running, command RPM up to

1500, down to 500, and then up to 1500 while

observing the noid light.

NOTE: This T ech 2 command may cause the engine to

“cut out” when RPM goes above 1500. If this occurs,

the “cutting out” will stop when the Tech 2 command for

the test is discontinued, or if the Tech 2 command is

changed to less than 1500 RPM.

Does each noid light cycle red and green (never

“OFF”)? — Go to

Step 5

Go to

Step 4

41. Check the following circuits for an open, short to

voltage, short ground, or poor connections at the

PCM:

DIAC “A” Low.

DIAC “A” High.

DIAC “B” Low.

DIAC “B” High.

2. If a problem is found, repair as necessary,

Was a problem found? — Verify repair Go to

Step 8

Step NoYesValue(s)Action

5Visually/physically inspect for following conditions:

DRestricted air intake system. Check for a possible

collapsed air intake duct, restricted air filter

element, or foreign objects blocking the air intake

system.

DThrottle body . Check for objects blocking the IAC

passage or throttle bore, excessive deposits in

the IAC passage and on the IAC pintle, and

excessive deposits in the throttle bore and on the

throttle plate.

Do any of the above require a repair? —

Refer to

appropriate

section for

on-vehicle

service Go to

Step 6

61. Check for a poor connection at the IAC harness

connector.

2. If a problem is found, replace faulty terminals as

necessary.

Was a problem found? — Verify repair Go to

Step 7

7Replace the IAC valve.

Is the action complete? — Verify repair —

8Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1509 IAC System High RPM

T321115

Circuit Description

The powertrain control module (PCM) controls engine

idle speed by adjusting the position of the idle air control

(IAC) motor pintle. The IAC is a bi-directional stepper

motor driven by two coils. The PCM applies current to the

IAC coils in steps (counts) to extend the IAC pintle into a

passage in the throttle body to decrease air flow. The

PCM reverses the current to retract the pintle, increasing

air flow. This method allows highly accurate control of idle

speed and quick response to changes in engine load. If

the PCM detect a condition where too high of an idle

speed is present and the PCM is unable to adjust idle

speed by increasing the IAC counts, DTC P1509 will set,

indicating a problem with the idle control system.

Conditions for Setting the DTC

DNo Tech 2 test is being run.

DNone of these DTCs are set: TP sensor, VSS, ECT,

EGR, fuel system, MAF, MAP, IAT, canister purge,

injector control or ignition control.

DBarometric pressure is above 75 kPa.

DEngine coolant temperature is above 50°C (120°F).

DEngine speed is more than 100-200 RPM higher than

desired idle, based upon coolant temperature.

DThe engine has been running for at least 125 seconds.

DVehicle speed is less than 1 mph.

DCanister purge duty cycle is above 10%.

DIgnition voltage is between 9.5 volts and 16.7 volts.

DEngine speed is higher than desired idle.

DAll of the above conditions are met for 5 seconds.

Action Taken When the DTC Sets

DThe PCM will illuminate the malfunction indicator lamp

(MIL) after the second consecutive trip in which the

fault is detected.

DThe PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P1509 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P1509 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM or IAC motor – Inspect

harness connectors for backed-out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal-to-wire

connection.

DDamaged harness – Inspect the wiring for damage.

DVacuum leak – Check for a condition that causes a

vacuum leak, such as disconnected or damaged

hoses, leaks at the EGR valve and the EGR pipe to the

intake manifold, leaks at the throttle body, faulty or

incorrectly installed PCV valve, leaks at the intake

manifold, etc.

DThrottle body – Check for sticking throttle plate. Also

inspect the IAC passage for deposits or objects which

keep the IAC pintle from fully extending.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

DTC P1509 –IAC System High RPM

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Start the engine.

2. Turn all accessories “OFF” (A/C, rear defroster,

etc.).

3. Using a T ech 2, command RPM up to 1500, down to

500, and then up to 1500 while monitoring “Engine

Speed” on the Tech 2.

NOTE: This T ech 2 command may cause the engine to

“cut out” when RPM goes above 1500. If this occurs,

the “cutting out” will stop when the Tech 2 command for

the test is discontinued, or if the Tech 2 command is

changed to less than 1500 RPM.

Does the “Engine Speed” remain within the specified

value of “Desired Idle” for each RPM command? ± 50 RPM

No trouble

found. Go to

Diagnostic

Aids

Go to

Step 3

31. Disconnect the IAC.

2. Install IAC Noid Light 5–8840–2312–0 or

equivalent.

3. With the engine running, command RPM up to

1500, down to 500, and then up to 1500 while

observing the noid light.

NOTE: This T ech 2 command may cause the engine to

“cut out” when RPM goes above 1500. If this occurs,

the “cutting out” will stop when the Tech 2 command for

the test is discontinued, or if the Tech 2 command is

changed to less than 1500 RPM.

Does each noid light cycle red and green (never

“OFF”)? — Go to

Step 5

Go to

Step 4

41. Check the following circuits for an open, short to

voltage, short ground, or poor connections at the

PCM:

DIAC “A” Low.

DIAC “A” High.

DIAC “B” Low.

DIAC “B” High.

2. If a problem its found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

Step NoYesValue(s)Action

5Visually/physically inspect for the following conditions:

DVacuum leaks.

DThrottle plate or throttle shaft for binding.

DAccelerator and cruise control cables for being

misadjusted or for binding.

DFaulty, missing, or incorrectly installed PCV

valve.

Do any of the above require a repair? —

Refer to

appropriate

section for

on-vehicle

service Go to

Step 6

61. Check for a poor connection at the IAC harness

connector.

2. If a problem is found, replace faulty terminals as

necessary.

Was a problem found? — Verify repair Go to

Step 7

7Replace the IAC valve.

Is the action complete? — Verify repair —

8Replace the PCM.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1625 PCM Unexpected Reset

Circuit Description

The powertrain control module (PCM) monitors

unexpected PCM reset. This will not turn on MIL light on,

only records code DTC P1625.

Conditions for Setting the DTC

DClock or COP (Computer Operating Properly) reset.

Action Taken When the DTC Sets

DThe PCM will not illuminate the malfunction indicator

lamp (MIL).

DThe PCM will store conditions which were present

when the DTC was set as Failure Records only. This

information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

DThe PCM will turn the MIL “OFF” on the third

consecutive trip cycle during which the diagnostic has

been run and the fault condition is no longer present.

DA history DTC P1625 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

DDTC P1625 can be cleared by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

DP1625 alone stored does not need diagnosis. Clear

DTC code.

DTC P1625 – PCM Unexpected Reset

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to Step 2

Go to

OBD

System

Check

21. Ignition is “ON”.

2. Install the Tech 2.

3. Start the engine at let it Idle.

4. On the Tech 2, select “DTC info”.

Does the Tech 2 indicate DTC P1625 failed? —Go to

Step 3

Go to

Diagnostic

Aids

31. Ignition is “ON”.

2. Clear DTC P1625 by using the Tech 2 “Clear Info”.

3. Start the engine at let it Idle.

4. On the Tech 2, select “DTC info”.

Does the Tech 2 indicate DTC P1625 failed? —Go to

Step 4

Go to

Diagnostic

Aids

41. Check for aftermarket electronics, such as

transceiver, stereos, and anti theft devices. May

radiate EMI into the control system if they are

improperly installed. (This may cause a false sensor

reading and turn on the MIL.)

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair —

Diagnostic Trouble Code (DTC) P1640 Output Driver Module (ODM) “A” Fault

Action Taken When the DTC Sets

DThe PCM will not illuminate the malfunction indicator

lamp (MIL).

DThe PCM will store conditions which were present

when the DTC was set as Failure Records only. This

information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

DA history DTC P1640 will clear after 40 consecutive

warm-up cycles occur without a fault.

DDTC P1650 can be cleared by using the Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

DPoor connection at PCM – Inspect harness connectors

for backed-out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and

poor terminal-to-wire connection.

DDamaged harness – Inspect the wiring harness for

damage, If the harness appears to be OK, disconnect

the PCM, turn the ignition “ON” and observe a

voltmeter connected to the suspect driver circuit at the

PCM harness connector while moving connectors and

wiring harnesses relates to the MIL. A change in

voltage will indicate the location of the fault.

DPoor connection at component – Examine for

damaged connectors, unplugged connector, or

damaged terminals at the following locations: canister

purge solenoid, Fuel level check.

Reviewing the Failure Records vehicle mileage since the

diagnostic test last failed may help determine how often

the condition that caused the DTC to be set occurs. This

may assist in diagnosing the condition.

The following PCM pins are controlled by

output driver modules (ODMs):

DA13 – MIL (Check Engine)

DA14 – Check T/M or Up-Shift

DA15 – EVAP Canister Purge

DA16 – Band Apply (4L30E)

DB14 – A/C Clutch

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

4. The Tech 2 Driver Module Status indicates the PCM

pin that is affected.

9. The Tech 2 may indicate “short circuit” even when

the problem is an open circuit. The cause of an

open circuit may be in the component itself.

11.A short to ground on the ignition side of the

component will blow the fuse. Since the fuse was

checked in Step 2, a short to ground would be

between the affected component and the PCM.

DTC P1640 –Output Driver Module (ODM) “A” Fault

Step Action Value(s) YesNo

1Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

2Check the fuse for the driver circuit that was shown as

faulty.

Was the fuse blown? —Go to

Step 3

Go to

Step 4

31. Check for a short to ground between the fuse and

the affected component.

2. Replace the fuse after making any necessary

repairs.

Is the action complete? — Verify repair —

41. Disconnect the PCM connector for the affected

driver circuit.

Is there any damage to the PCM pin or connector? —Go to

Step 5

Go to

Step 6

5Repair the damaged pin or terminal.

Is the action complete? — Verify repair —

6Were either of the lamp circuits for “Check Engine” or

“Check Trans.” indicated as faulty by the Tech 2? —Go to

Step 7

Go to

Step 13

Step NoYesValue(s)Action

71. Leave the PCM connector for the lamp driver circuit

disconnected.

2. Ignition “ON.”

3. Using a DVM, check the voltage at the PCM

connector for the affected lamp driver circuit.

Was the voltage equal to the specified value? B+ Go to

Step 15

Go to

Step 8

81. Ignition “ON.”

2. Check for battery voltage at the fuse for the affected

lamp circuit.

Was battery voltage available at the fuse? —Go to

Step 10

Go to

Step 9

9Repair the open circuit between the ignition switch and

the fuse.

Is the action complete? — Verify repair —

10 1. Ignition “OFF.”

2. Disconnect the PCM connector for the affected

driver terminal.

3. Connect an ohmmeter between a good ground and

the PCM connector for the affected driver.

Did the ohmmeter indicate continuity? —Go to

Step 11

Go to

Step 12

11 Repair the short to ground between the affected

component and its PCM driver terminal.

Is the action complete? — Verify repair —

12 Repair the open circuit between the fuse and the PCM

driver terminal for the affected circuit.

Is the action complete? — Verify repair —

13 1. Connect the PCM.

2. Start the engine and let it idle.

3. Backprobe the affected terminal at the PCM with a

DVM.

Was the voltage equal to the specified value? B+ Go to

Step 15

Go to

Step 14

14 1. Run the engine at idle.

2. Check for battery voltage at the fuse for the affected

circuit.

Was battery voltage available at the fuse? —Go to

Step 10

Go to

Step 9

15 Replace the PCM.

Is the action complete? — Verify repair —

Symptom Diagnosis

Preliminary Checks

Before using this section, perform the “On–Board

Diagnostic (OBD) System Check” and verify all of the

following items:

DThe powertrain control module (PCM) and

malfunction indicator lamp (MIL) (Check Engine

lamp) are operating correctly.

DThere are no DTC(s) stored.

DTech 2 data is within normal operating range. Refer to

Typical Scan Data Values

DVerify the customer complaint and locate the correct

symptom in the table of contents. Perform the

procedure included in the symptom chart.

Visual/Physical Check

Several of the symptom procedures call for a careful

visual/physical check. This can lead to correcting a

problem without further checks and can save valuable

time.

This check should include the following items:

DPCM grounds for cleanliness, tightness and proper

location.

DVacuum hoses for splits, kinks, and proper

connections, as shown on the “Vehicle Emission

Control Information” label. Check thoroughly for any

type of leak or restriction.

DAir intake ducts for collapsed or damaged areas.

DAir leaks at throttle body mounting area, mass air flow

(MAF) sensor and intake manifold sealing surfaces.

DIgnition components for cracking, hardness, and

carbon tracking.

DWiring for proper connections, pinches and cuts.

Intermittents

IMPORTANT:An intermittent problem may or may not

turn on the malfunction indicator lamp (MIL) or store a

DTC. DO NOT use the Diagnostic Trouble Code (DTC)

charts for intermittent problems. The fault must be

present to locate the problem.

Most intermittent problems are caused by faulty electrical

connections or wiring. Perform a careful visual/physical

check for the following conditions:

DPoor mating of the connector halves or a terminal not

fully seated in the connector (backed out).

DImproperly formed or damaged terminal.

DAll connector terminals in the problem circuit should

be carefully checked for proper contact tension.

DPoor terminal–to–wire connection. This requires

removing the terminal from the connector body to

check.

Road test the vehicle with a 5-8840-0285-0 Digital

Multimeter connected to a suspected circuit. An

abnormal voltage when the malfunction occurs is a good

indication that there is a fault in the circuit being

monitored.

Use a Tech 2 to help detect intermittent conditions. The

scan tool has several features that can be used to locate

an intermittent condition. Use the following feature to find

intermittent faults:

DUsing a Tech 2’s “Freeze Frame” buffer or “Failure

Records” buffer can aid in locating an intermittent

condition. Review and record the information in the

freeze frame or failure record associated with the

intermittent DTC being diagnosed. The vehicle can

be driven within the conditions that were present

when the DTC originally set.

To check for loss of diagnostic code memory, disconnect

the MAP sensor and idle the engine until the MIL (Service

Engine Soon lamp) comes on. DTC P0107 should be

stored and kept in memory when the ignition is turned

“OFF.” If not, the PCM is faulty. When this test is

completed, make sure that you clear the DTC P0107 from

memory.

An intermittent MIL (Check Engine lamp) with no stored

DTC may be caused by the following:

DIgnition coil shorted to ground and arcing at ignition

wires or plugs.

DMIL (Check Engine lamp) wire to PCM shorted to

ground.

DPoor PCM grounds. Refer to the PCM wiring

diagrams.

Check for improper installation of electrical options such

as lights, cellular phones, etc. Check all wires from the

PCM to the ignition coils for poor connections.

Check for an open diode across the A/C compressor

clutch and check for other open diodes (refer to wiring

diagrams in

Electrical Diagnosis

If problem has not been found, refer to

PCM Connector

Symptom

tables.

Hard Start Symptom

Step Action Value(s) YesNo

1DEFINITION:

Engine cranks, but does not start for a long time. Does

eventually run, or may start but immediately stalls.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

4Check engine coolant temperature (ECT) sensor for

shift in value. After 8 hours with the hood up and the

engine not running, connect the Tech 2. With the

ignition “ON” and the engine not running, compare

engine coolant temperature to intake air temperature.

Are ECT and IAT within the specified value of each

other? ± 5°C (± 9°F) Go to

Step 9

Go to

Step 5

51. Using a Tech 2, display the engine coolant

temperature and note the value.

2. Check the resistance of the engine coolant

temperature sensor.

3. Refer to

Engine Coolant Temperature Sensor

Temperature vs. Resistance

chart on

DTC P0118

Diagnostic Support

for resistance specifications.

Is the resistance value near the resistance for the

temperature noted? —Go to

Step 7

Go to

Step 6

6Replace the ECT sensor.

Is the action complete? — Verify repair —

7Locate and repair high resistance or poor connection in

the ECT signal circuit or the ECT sensor ground.

Is the action complete? — Verify repair —

81. Check for a faulty, plugged, or incorrectly installed

PCV valve.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

91. Check for water-or alchol-contaminated fuel.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 10

10 1. Perform the procedure in

Fuel System Pressure

Test

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 11

11 1. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to

Electric Ignition

System

for procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 12

Step NoYesValue(s)Action

12 1. Remove spark plugs. Check for wet plugs, cracks,

wear, improper gap, burned electrodes, or heavy

deposits. Refer to

Electronic Ignition System

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 13

13 1. Check for a loose ignition coil ground.

Refer to

Electronic Ignition System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

14 1. Remove the ignition coils and check the ignition

coils for cracks or carbon tracking.

2. If a problem is found, replace affected coil(s) as

necessary.

Was a problem found? — Verify repair Go to

Step 15

15 1. Check IAC operation. Perform the procedure in the

DTC P1508, 1509, Step 5

diagnostic table.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 16

16 1. Check for the following engine mechanical

problems (refer to

Engine Mechanical

DLow compression

DLeaking cylinder head gaskets

DWorn or incorrect camshaft

DCamshaft drive belt slipped or stripped

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 17

17 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records buffer

DAll electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Surges and/or Chuggles Symptom

Step Action Value(s) YesNo

1DEFINITION:

Engine power variation under steady throttle or cruise.

Feels like the vehicle speeds up and slows down with

no change in the accelerator pedal.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

4Be sure that the driver understands transmission

torque converter clutch and A/C compressor operation

as explained in the owner’s manual.

Inform the customer how the TCC and the A/C clutch

operate.

Is the customer experiencing a normal condition? —System OK Go to

Step 5

51. Check the the fuel control heated oxygen sensors

(HO2S, B1S1 and B2S1). The fuel control heated

oxygen sensors (HO2S) should respond quickly to

different throttle positions. If they don’t, check them

for silicone or other contaminants from fuel or use of

improper RTV sealant. The sensors may have a

white powdery coating.

Silicone contamination causes a high but false

HO2S signal voltage (rich exhaust indication).

The PCM will then reduce the amount of fuel

delivered to the engine, causing a severe

driveability problem. For more information, refer

Powertrain Control Module (PCM) and Sensors

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 6

61. Check the fuel pressure. Refer to

Fuel System

Pressure Test

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 7

7Monitor the long term fuel trim on the Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? —Go to

Step 8

Go to

Step 9

81. Check items that can cause the engine to run rich.

Refer to

Diagnostic Aids

DTC P0172 Diagnostic

Support

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 10

Verify repair

91. Check items that can cause the engine to run lean.

Refer to

Diagnostic Aids

DTC P0171

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 10

Verify repair

Step NoYesValue(s)Action

10 1. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to

Electric Ignition

System

for procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 11

11 1. Check for a loose ignition coil ground.

Refer to

Electric Ignition System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 12

12 1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

13 1. Remove the spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits. Refer to

Electronic Ignition

System

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

14 1. Check the injector connections.

2. If any of the injector connectors are connected to an

incorrect cylinder, correct as necessary.

Was a problem found? — Verify repair Go to

Step 15

15 1. Check PCM grounds for the cleanliness, tightness

and proper locations. Refer to the PCM wiring

diagrams in

Electrical Diagnosis

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 16

16 1. Check MAF sensor connections.

2. If a problem is found, replace the faulty terminals as

necessary. Refer to

Electrical Diagnosis

for wiring

repair procedures.

Was a problem found? — Verify repair Go to

Step 17

17 1. Visually/physically check vacuum hoses for splits,

kinks, and proper connections and routing as

shown on the “Vehicle Emission Control

Information” label.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 18

Step NoYesValue(s)Action

18 1. Check the exhaust system for possible restriction:

DInspect the exhaust system for damaged or

collapsed pipes.

DInspect the muffler for heat distress or possible

internal failure.

DCheck for a possible plugged three-way

catalytic converter by checking the exhaust

system back pressure. Refer to

Restricted

Exhaust System Check

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 19

19 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records buffer

DAll electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Lack of Power, Sluggish or Spongy Symptom

Step Action Value(s) YesNo

1DEFINITION:

Engine delivers less than expected power. Little or no

increase in speed when accelerator pedal is pushed

down part-way.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

41. Remove and check the air filter element for dirt or

restrictions. Refer to

Air Intake System

On-Vehicle Service

2. Replace the air filter element if necessary.

Was a repair required? — Verify repair Go to

Step 5

51. Check for water-or alcohol-contaminated fuel.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 6

61. Using a Tech 2, monitor the knock sensor (KS)

system for excessive spark retard activity. Refer to

Knock Sensor (KS) System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 7

71. Install the Tech 2.

2. Run the engine at idle.

3. On the Tech 2, select F3: Miscellaneous Test, F6:

Variable Intake Manifold.

4. Repeat Switch ON or OFF of VIM solenoid valve by

using the Tech 2.

5. Check the working solenoid sound if the actuator

works normally.

6. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

81. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to

Electronic Ignition

System

for procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

Step NoYesValue(s)Action

91. Remove the spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits. Refer to

Electronic Ignition

System

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 10

10 1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 11

11 1. Check the PCM grounds for the cleanliness,

tightness and proper locations. Refer to the PCM

wiring diagrams in

Electrical Diagnosis

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 12

12 1. Check the exhaust system for possible restriction:

DInspect the exhaust system for damaged or

collapsed pipes.

DInspect the muffler for heat distress or possible

internal failure.

DCheck for a possible plugged three-way

catalytic converter by checking the exhaust

system back pressure. Refer to

Restricted

Exhaust System Check

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 13

13 1. Check the torque converter clutch (TCC) for proper

operation. Refer to

4L30–E Transmission

Diagnosis

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

14 1. Check for an engine mechanical problem. Check

for low compression, incorrect or worn camshaft,

loose timing belt, etc. Refer to

Engine Mechanical

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 15

15 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records buffer

DAll electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Detonation/Spark Knock Symptom

Step Action Value(s) YesNo

1DEFINITION:

A mild to severe ping, usually worse under acceleration.

The engine makes sharp metallic knocks that change

with throttle opening.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

4If Tech 2 readings are normal (refer to

Typical Scan

Values

) and there are no engine mechanical faults, fill

the fuel tank with a known quality gasoline that has a

minimum octane rating of 87 and re-evaluate the

vehicle performance.

Is detonation present? —Go to

Step 5

Verify repair

51. Check the transmission range switch circuit. Use a

Tech 2 and be sure the Tech 2 indicates that the

vehicle is in drive with the gear selector in drive or

overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary (refer to

4L30-E Automatic Transmission Diagnosis

Was a problem found? — Verify repair Go to

Step 6

61. Check TCC operation. Refer to

4L30-E

Transmission Diagnosis

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 7

71. Check for obvious overheating problems:

DLow engine coolant.

DRestricted air flow to radiator, or restricted

water flow through radiator.

DCorrect coolant solution should be a 50/50 mix

of approved antifreeze/coolant and water.

Refer to

Engine Cooling

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

81. Check fuel a leak.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

91. Check items that can cause an engine to run lean

(long term fuel trim significantly in the positive

range). For a lean condition, refer to

Diagnostic

Aids

DTC P0171 Diagnostic Support

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 10

Step NoYesValue(s)Action

10 1. Spark plugs for proper heat range. Refer to

General

Information

2. If incorrect spark plugs are installed, replace spark

plugs as necessary.

Did any spark plugs require replacement? — Verify repair Go to

Step 11

11 1. Remove excessive carbon buildup with a top engine

cleaner. Refer to instructions on the top engine

cleaner can.

2. Re-evaluate vehicle performance.

Is detonation still present? —Go to

Step 12

Verify repair

12 1. Check for an engine mechanical problem. Perform

a cylinder compression check. Refer to

Engine

Mechanical

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 13

13 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records buffer

DAll electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Rough, Unstable, or Incorrect Idle, Stalling Symptom

Step Action Value(s) YesNo

1DEFINITION:

Engine runs unevenly at idle. If severe, the engine or

vehicle may shake. Engine idle speed may vary in

RPM. Either condition may be severe enough to stall

the engine.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? —Go to

Step 13

Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

41. Check the PCM grounds for cleanliness, tightness

and proper routing. Refer to the PCM wiring

diagrams in

Electrical Diagnosis

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 5

5Observe the long term fuel trim on the Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? —Go to

Step 6

Go to

Step 7

61. Check items that can cause the engine to run rich.

Refer to

Diagnostic Aids

DTC P0172 Diagnostic

Support

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

7Is the long term fuel trim significantly in the positive

range (lean condition)? —Go to

Step 8

Go to

Step 9

81. Check items that can cause the engine to run lean.

Refer to

Diagnostic Aids

DTC P0171 Diagnostic

Support

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

91. Check for incorrect idle speed. Ensure that the

following conditions are present:

DThe engine is fully warm.

DThe accessories are “OFF.”

2. Using a Tech 2, monitor the IAC position.

Is the IAC position within the specified values?

Between 10

and 50

counts Go to

Step 11

Go to

Step 10

Step NoYesValue(s)Action

10 1. Visually/physically inspect for the following

conditions:

DRestricted air intake system. Check for a

possible collapsed air intake duct, restricted

air filter element, or foreign objects blocking

the air intake system.

DThrottle body. Check for objects blocking the

IAC passage or throttle bore, excessive

deposits in the IAC passage and on the IAC

pintle, and excessive deposits in the throttle

bore and on the throttle plate.

DLarge vacuum leak. Check for a condition that

causes a large vacuum leak, such as an

incorrectly installed or faulty crankcase

ventilation valve or a disconnected brake

booster hose.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

11 Check the injector connections. If any of the injectors

are connected to an incorrect cylinder, correct as

necessary.

Was a problem found? — Verify repair Go to

Step 12

12 1. Perform the “Injector Coil/Balance Test” in

Fuel

Metering System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 13

13 1. Check for fuel in the pressure regulator vacuum

hose.

2. If fuel is present, replace the fuel pressure regulator

assembly. Refer to

Fuel Metering System

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

14 1. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to

Electronic Ignition

System

for the procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 15

15 1. Remove spark plugs. Check for wet plugs, cracks,

wear, improper gap, burned electrodes, or heavy

deposits. Refer to

Electronic Ignition System

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 16

16 1. Check for a loose ignition coil ground.

Refer to

Electrical Ignition System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 17

Step NoYesValue(s)Action

17 1. Check ignition coils for cracks or carbon tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 18

18 Using a Tech 2, monitor the throttle position (TP) angle

with the engine idling.

Is the TP angle at the specified value and steady? 0% Go to

Step 19

Refer to

DTC

P0123

for

further

diagnosis

19 1. Check the positive crankcase ventilation (PCV)

valve for proper operation. Refer to

Crankcase

Ventilation System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 20

20 1. Check the transmission range switch circuit. Use a

Tech 2 and be sure the Tech 2 indicates that the

vehicle is in drive with the gear selector in drive or

overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary (refer to

4L30-E Automatic Transmission Diagnosis

Was a problem found? — Verify repair Go to

Step 21

21 1. Check for the following engine mechanical items.

Refer to

Engine Mechanical

for diagnosis

procedures:

DLow compression

DSticking or leaking valves

DWorn camshaft lobe(s)

DCamshaft drive belt slipped or stripped

DIncorrect valve timing

DWorn rocker arms

DBroken valve springs

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 22

22 1. Check for faulty motor mounts. Refer to

Engine

Mechanical

for inspection of mounts.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 23

23 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records buffer

DAll electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Poor Fuel Economy Symptom

Step Action Value(s) YesNo

1DEFINITION:

Fuel economy, as measured by an actual road test, is

noticeably lower than expected. Also, economy is

noticeably lower than it was on this vehicle at one time,

as previously shown by an actual road test. (Larger than

standard tires will cause odometer readings to be

incorrect, and that may cause fuel economy to appear

poor when it is actually normal.)

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

4Check owner’s driving habits.

DIs the A/C “ON” full time (defroster mode “ON”)?

DAre tires at the correct pressure?

DAre excessively heavy loads being carried?

DIs acceleration too much, too often?

Was a problem found? —Go to

Step 5

Go to

Step 6

5Review the items in Step 4 with the customer and

advise as necessary.

Is the action complete? —System OK —

61. Visually/physically check: V acuum hoses for splits,

kinks, and improper connections and routing as

shown on the “Vehicle Emission Control

Information” label.

2. If a problem is found, repair as necessary.

Was a repair required? — Verify repair Go to

Step 7

71. Remove and check the air filter element for dirt or for

restrictions. Refer to

Air Intake System

2. Replace the air filter element if necessary.

Was a repair required? — Verify repair Go to

Step 8

81. Remove spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits. Refer to

Spark Plug Replacement

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

91. Check for low engine coolant level. Refer to

Engine

Cooling

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 10

Step NoYesValue(s)Action

10 1. Check for an incorrect or faulty engine thermostat.

Refer to

Engine Cooling

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 11

11 1. Check for low engine compression. Refer to

Engine

Mechanical

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 12

12 1. Check the TCC operation. Refer to

4L30-E

Transmission Diagnosis

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 13

13 1. Check the exhaust system for possible restriction:

DInspect the exhaust system for damaged or

collapsed pipes.

DInspect the muffler for heat distress or possible

internal failure.

DCheck for a possible plugged three-way

catalytic converter by checking the exhaust

system back pressure. Refer to

Restricted

Exhaust System Check

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

14 Check for proper calibration of the speedometer.

Does the speed indicated on the speedometer closely

match the vehicle speed displayed on the Tech 2? —Go to

Step 16

Go to

Step 15

15 Diagnose and repair an inaccurate speedometer

condition as necessary. Refer to

Vehicle Speed

Sensor

Electrical Diagnosis

Was a problem found? — Verify repair —

16 1. Check the air intake system and the crankcase for

air leaks. Refer to

Air Intake System

and

Crankcase Ventilation System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 17

17 1. Review all diagnostic procedures within this table.

2. When all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records buffer

DAll connections within a suspected circuit

and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 18

18 Perform the procedure in

Fuel System Pressure Test

Was the fuel pressure normal? —

Contact

Technical

Assistance Verify repair

Excessive Exhaust Emissions or Odors Symptom

Step Action Value(s) YesNo

1DEFINITION:

Vehicle fails an emission test. Vehicle has excessive

“rotten egg” smell. (Excessive odors do not necessarily

indicate excessive emissions.)

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? —Go to

Step 13

Go to

Step 3

3Was a thorough visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

41. Check for vacuum leaks. Check vacuum lines,

intake manifold, throttle body, etc.

2. If a problem is found, repair as necessary.

Were any vacuum leaks located? —Go to

Step 13

Go to

Step 5

51. Check the fuel cap for proper installation.

2. Secure the fuel cap if necessary.

Was the fuel cap installed properly? —Go to

Step 6

Go to

Step 13

61. Check the fuel pressure. Perform the procedure in

Fuel System Pressure Test

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 7

71. Check for a faulty, plugged, or incorrectly installed

crankcase ventilation valve; also check the

crankcase ventilation system for plugging.

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 8

81. Check the injector connections.

2. If any of the injectors are connected to an incorrect

cylinder, correct as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 9

91. Perform the “Injector Coil/Balance Test” in

Fuel

Metering System

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 10

10 1. Refer to

Engine Cooling

for cooling system

diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 11

11 1. Check EVAP canister for fuel loading. Refer to

Evaporative Emission Control System

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 12

Step NoYesValue(s)Action

12 1. Remove excessive carbon buildup with a top engine

cleaner . Refer to the instructions on the top engine

cleaner can.

2. Perform the exhaust emission test.

Does the vehicle pass the test? —System OK Go to

Step 14

13 Perform the exhaust emission test.

Does the vehicle pass the test? —System OK Go to

Step 14

14 Does the exhaust emission test indicate excessive CO

and HC levels or is long term fuel trim significantly in the

negative range (rich condition)? —Go to

Step 15

Go to

Step 16

15 1. Check items that can cause the engine to run rich.

Refer to

Diagnostic Aids

DTC P0172 Diagnostic

Support

. Make any necessary repairs.

2. Perform the exhaust emission test.

Does the vehicle pass the test? —System OK Go to

Step 17

16 1. Check items that can cause the engine to run lean.

Refer to

Diagnostic Aids

DTC P0171 Diagnostic

Support

. Make any necessary repairs.

2. Perform the exhaust emission test.

Does the vehicle pass the test? —System OK Go to

Step 17

17 1. Check the EGR system.

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 18

18 1. Check for an engine mechanical problem.

Perform a cylinder compression check (refer to

Engine Mechanical

2. If a problem is found, repair as necessary.

Was a problem found? —Go to

Step 13

Go to

Step 19

19 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records butter

DAll electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Dieseling, Run-On Symptom

Step Action Value(s) YesNo

1DEFINITION:

Engine continues to run after key is turned “OFF,” but

runs very rough. If engine runs smooth, check ignition

switch and adjustment.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

41. Check for a short between B+ and any of the ignition

feed circuits.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 5

51. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records butter

DAll electrical connections within a suspected

circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Backfire Symptom

Step Action Value(s) YesNo

1DEFINITION:

Fuel ignites in the intake manifold, or in the exhaust

system, making a loud popping noise.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

41. Check for proper ignition voltage coil output with

spark tester 5-8840-0383-0. Refer to

Electronic

Ignition System

for procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 5

51. Remove spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits. Refer to

Electronic Ignition

System

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs. Refer to

DTC P0172

to determine the

cause of a rich condition or

Engine Mechanical

for an oil

fouling condition.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 6

61. Visually/physically inspect the ignition coils for

cracks.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 7

71. Check for an intermittent ignition system

malfunction:

DIntermittent CKP 58X signal.

DIntermittent ignition feed circuit or sensor

ground circuit to the crankshaft position

sensor.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

81. Check the fuel pressure. Refer to

Fuel System

Pressure Test

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

Step NoYesValue(s)Action

91. Check for the following engine mechanical

conditions.

Refer to

Engine Mechanical

for diagnosis

procedures:

DLow compression

DSticking or leaking valves

DWorn camshaft lobe(s)

DCamshaft drive belt slipped or stripped

DIncorrect valve timing

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 10

10 1. Check the intake and exhaust manifold(s) for

casting flash. Refer to

Engine Mechanical

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 11

11 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records butter

DAll electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Cuts Out, Misses Symptom

Step Action Value(s) YesNo

1DEFINITION:

Steady pulsation or jerking that follows engine speed;

usually more pronounced as engine load increases.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? —Go to

Step 13

Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

41. Check the PCM grounds for clearness, tightness

and proper routing. Refer to the PCM wiring

diagrams in

Electrical Diagnosis

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 5

5Observe the long term fuel trim on the Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? —Go to

Step 6

Go to

Step 7

61. Check items that can cause the engine to run rich.

Refer to

Diagnostic Aids

DTC P0172 Diagnostic

Support

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

7Is the long term fuel trim significantly in the positive

range (lean condition)? —Go to

Step 8

Go to

Step 9

81. Check items that can cause the engine to run lean.

Refer to

Diagnostic Aids

DTC P0171 Diagnostic

Support

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 9

91. Check for incorrect idle speed. Ensure that the

following conditions are present:

DThe engine is fully warm.

DThe accessories are “off.”

2. Using a Tech 2, monitor the IAC position.

Is the IAC position within the specified values?

Between 5

and 50

counts Go to

Step 11

Go to

Step 10

Step NoYesValue(s)Action

10 1. Visually/physically inspect for the following

conditions:

DRestricted air intake system. Check for a

possible collapsed air intake duct, restricted

air filter element, or foreign objects blocking

the air intake system.

DThrottle body. Check for objects blocking the

IAC passage or throttle bore, excessive

deposits in the IAC passage and on the IAC

pintle, and excessive deposits in the throttle

bore and on the throttle plate.

DLarge vacuum leak. Check for a condition that

causes a large vacuum leak, such as an

incorrectly installed or faulty PCV valve or

brake booster hose disconnected .

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 8

11 Check the injector connections. If any of the injectors

are connected to an incorrect cylinder, correct as

necessary.

Was a problem found? — Verify repair Go to

Step 12

12 1. Perform the “Injector Coil/Balance Test” in

Fuel

Metering System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 13

13 1. Check for fuel in the pressure regulator vacuum

hose.

2. If fuel is present, replace the fuel pressure regulator

assembly. Refer to

Fuel Metering System

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

14 1. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to

Electronic Ignition

System

for the procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 15

15 1. Remove spark plugs. Check for wet plugs, cracks,

wear, improper gap, burned electrodes, or heavy

deposits. Refer to

Electronic Ignition System

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 16

16 1. Check for a loose ignition coil ground.

Refer to

Electronic Ignition System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 17

Step NoYesValue(s)Action

17 1. Check ignition coils for cracks or carbon tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 18

18 Using a Tech 2, monitor the TP angle with the engine

idling.

Is the TP angle at the specified value and steady? 0% Go to

Step 19

Refer to

DTC

P0123

for

further

diagnosis

19 1. Check the PCV valve for proper operation. Refer to

Crankcase Ventilation System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 20

20 1. Check the transmission range switch circuit. Use a

Tech 2 and be sure the Tech 2 indicates that the

vehicle is in drive with the gear selector in drive or

overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary (refer to

4L30-E Automatic Transmission Diagnosis

Was a problem found? — Verify repair Go to

Step 21

21 1. Check the following engine mechanical items.

Refer to

Engine Mechanical

for diagnosis

procedures:

DLow compression

DSticking or leaking valves

DWorn camshaft lobe(s)

DCamshaft drive belt slipped or stripped

DIncorrect valve timing

DWorn rocker arms

DBroken valve springs

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 22

22 1. Check for faulty motor mounts. Refer to

Engine

Mechanical

for inspection of mounts.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 23

23 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records butter

DAll electrical connections within a suspected

circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Hesitation, Sag, Stumble Symptom

Step Action Value(s) YesNo

1DEFINITION:

Momentary lack of response as the accelerator is

pushed down. Can occur at any vehicle speed. Usually

most pronounced when first trying to make the vehicle

move, as from a stop sign. May cause the engine to stall

if severe enough.

Was the “On-Board Diagnostic (OBD) System Check”

performed? —Go to

Step 2

Go to

OBD

System

Check

21. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to

Step 3

3Was a visual/physical check performed?

—Go to

Step 4

Go to

Visual/Physic

al Check

41. Check the fuel control heated oxygen sensors

(HO2S, B1S1 and B2S1). The fuel control heated

oxygen sensors (HO2S) should respond quickly to

different throttle positions. If they don’t, check them

for silicon or other contaminants from fuel or use of

improper RTV sealant. The sensors may have a

white powdery coating.

Silicon contamination causes a high but false

HO2S signal voltage (rich exhaust indication).

The PCM will then reduce the amount of fuel

delivered to the engine, causing a severe

driveability problem. For more information, refer

Powertrain Control Module (PCM) and Sensors

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 5

51. Check the fuel pressure. Refer to

Fuel System

Pressure Test

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 6

6Observe the TP angle display on the Tech 2 while

slowly increasing throttle pedal.

Does the TP angle display steadily increase from 0% at

closed throttle to 100% at WOT? —Go to

Step 7

Go to

Step 18

7Monitor the long term fuel trim on the Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? —Go to

Step 8

Go to

Step 9

81. Check items that can cause the engine to run rich.

Refer to

Diagnostic Aids

DTC P0172 Diagnostic

Support

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 10

91. Check items that can cause the engine to run lean.

Refer to

Diagnostic Aids

DTC P0171 Diagnostic

Support

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 10

Step NoYesValue(s)Action

10 1. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to

Electronic Ignition

System

for the procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 11

11 1. Check for a loose ignition coil ground.

Refer to

Electronic Ignition System

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 12

12 1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 13

13 1. Remove spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits. Refer to

Electronic Ignition

System

NOTE: If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 14

14 1. Check the PCM grounds for clearness, tightness

and proper routing. Refer to the PCM wiring

diagrams in Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 15

15 1. Check the MAF sensor connections.

2. If a problem is found, replace the faulty terminals as

necessary. Refer to

Electrical Diagnosis

for wiring

repair procedures.

Was a problem found? — Verify repair Go to

Step 16

16 1. Visually/physically check vacuum hoses for splits,

kinks, and proper connections and routing as

shown on the “Vehicle Emission Control

Information” label.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to

Step 17

17 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

DVisual/physical inspection

DTech 2 data

DFreeze Frame data/Failure Records butter

DAll electrical connections within a suspected

circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Technical

Assistance

Default Matrix Table

Service Procedure Default Strategy

A referral strategy has been established to assist the

technician with additional information when the cause of

the failure cannot be determined. If no problem is found

after performing diagnostics, then refer to the default

matrix table for further diagnostic information.

Default Matrix Table

Strategy Based Diagnostic Charts Initial Diagnosis Default Section(s)

On-Board Diagnostic (OBD) System

Check Vehicle does not enter diagnostics. Chassis Electrical

On-Board Diagnostic (OBD) System

Check Vehicle enters diagnostics and

communicates with the Tech 2. MIL is

“ON” in diagnostics. Engine does not

start and run.

Ignition System Check

On-Board Diagnostic (OBD) System

Check Engine starts and runs, no PCM codes

set. Customer complains of vibration. —

On-Board Diagnostic (OBD) System

Check Engine starts and runs, no PCM codes

set. Customer complains of harsh or

soft shift, poor performance, delayed or

no engagement into drive or reverse,

transmission fluid leak, transmission

noise or vibration, or improper TCC

operation.

Automatic Transmission

PCM Power and Ground Check On-Board Diagnostic (OBD) System

Check. Chassis Electrical

PCM Power and Ground Check On-Board Diagnostic (OBD) System

Check. PCM power and ground circuits

OK. Data link voltage incorrect.

Chassis Electrical

On-Board Diagnostic (OBD) System

Check Engine starts and runs, no PCM codes

set. Customer complains of harsh or

soft shift, poor performance, delayed or

no engagement into drive or reverse,

transmission fluid leak, transmission

noise or vibration, or improper TCC

operation.

Automatic Transmission

Symptoms Initial Diagnosis Default Section(s)

Intermittents 1. On-board diagnostic (OBD)

system check.

2. Careful visual/physical inspections.

Chassis Electrical

Hard Starts 1. OBD system check.

2. Sensors (ECT, MAP, MAF, TP) ;

MAP output chart.

3. Fuel system electrical test, fuel

system diagnosis.

4. Ignition system.

5. IAC system check.

Engine Mechanical, Ignition

System Check, Exhaust System

Diagnosis

Surges and/or Chuggles 1. OBD system check.

2. Heated oxygen sensors.

3. Fuel system diagnosis.

4. Ignition system.

Calibration ID “Broadcast”

/Service Bulletins, Ignition

System Check, Generator

Output, Exhaust System

Diagnosis, 4L30-E System Test

Symptoms Initial Diagnosis Default Section(s)

Lack of Power, Sluggish or Spongy 1. OBD system check.

2. Fuel system diagnosis.

3. Ignition system.

4. Knock sensor.

5. EGR operation.

6. EGR system check.

Refer to

Exhaust System

Engine Exhaust

, TCC

Operation, Calibration

ID/Service Bulletins

Detonation/Spark Knock 1. OBD system check.

2. Transmission range switch.

3. EGR operation.

4. EGR system check.

5. TCC operation.

6. Fuel system diagnosis.

7. Ignition system.

8. Knock sensor.

TCC operation, Cooling System,

Ignition System Check,

Calibration ID/Service Bulletins

Hesitation, Sag, Stumble 1. OBD system check.

2. TP.

3. MAP output check.

4. Fuel system diagnosis.

5. Fuel injector and fuel injector

balance test.

6. EVAP emission canister purge

valve.

7. Ignition system.

EGR Operation, EGR System

Check, Generator Output

Voltage (refer to

Chassis

Electrical

), Calibration

ID/Service Bulletins, Ignition

System Check

Cuts Out, Misses 1. OBD system check.

2. Cylinder balance test. Ignition System Check

Rough, Unstable, or Incorrect Idle,

Stalling 1. OBD system check.

2. Fuel injector and fuel injector

balance test.

3. EVAP emission canister purge

valve check.

4. Ignition system.

5. IAC operation.

6. EGR operation.

MAP Output Check, Throttle

Linkage, IAC System Check,

EGR System Check, A/C Clutch

Control Circuit Diagnosis,

Crankcase Ventilation System,

Calibration ID/Service Bulletins,

Generator Output Voltage (refer

Chassis Electrical

), Exhaust

Diagnosis

Poor Fuel Economy 1. OBD system check.

2. Careful visual/physical inspection.

3. Ignition system.

4. Cooling system.

TCC Operation, Exhaust

System (refer to

Engine

Exhaust

)

Engine Cranks But Will Not Run 1. OBD system check. Fuel System Electrical

Diagnosis, Fuel System

Diagnosis, Fuel Injector and

Fuel Injector Balance Test.

Symptoms Initial Diagnosis Default Section(s)

Excessive Exhaust Emissions or

Odors 1. OBD system check.

2. Emission test.

3. Cooling system.

4. Fuel system diagnosis.

5. Fuel injector and fuel injector

balance test.

6. EVAP emission canister purge

valve.

7. Crankcase ventilation system.

8. Ignition system.

9. MAP output check.

EGR System Check, Exhaust

Diagnosis, Calibration

ID/Service Bulletins

Dieseling, Run-On 1. OBD system check.

2. Careful visual/physical inspection.

3. Fuel system diagnosis.

—

Backfire 1. OBD system check.

2. Ignition system.

3. Fuel system diagnosis.

4. Fuel injector and fuel injector

balance test.

5. EGR operation, EGR system

check.

Exhaust System Diagnosis,

Intake Casting Flash, Ignition

System Check

Evaporative Emissions 1. OBD system check.

2. Careful visual/physical inspection.

3. Fuel system diagnosis.

—

Heated Oxygen Sensors 1. OBD system check.

2. Careful visual/physical inspection. Exhaust System

On-Vehicle Service Camshaft

Position (CMP) Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Remove the engine cover.

3.Remove the common chamber assembly.

Refer to Common Chamber in Engine Mechanical.

014RW120

4.Disconnect the electrical connector to the CMP

sensor.

014RV053

5.Remove the CMP retaining bolt from the side of left

cylinder head.

6.Remove the CMP sensor from the cylinder head.

Inspection Procedure

1.Inspect the sensor O-ring for cracks or leaks.

2.Replace the O-ring if it is worn or damaged.

3.Lubricate the new O-ring with engine oil.

4.Install the lubricated O-ring.

Installation Procedure

1.Install the CMP sensor in the cylinder head.

2.Install the CMP sensor retaining bolt.

Tighten

DTighten the retaining screw to 9 N·m

(0.9kg·m/78 lb in.).

3.Connect the electrical connector to the CMP sensor.

014RV053

4.Install the common chamber assembly.

Refer to Common Chamber in Engine Mechanical.

014RW106

5.Install the engine cover.

6.Connect the negative battery cable.

Crankshaft Position (CKP)

Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the electrical connector to the CKP

sensor.

3.Remove one bolt and the CKP sensor from the right

side of the engine block, just behind the mount.

NOTE:Use caution to avoid any hot oil that might drip

out.

TS22909

Inspection Procedure

1.Inspect the sensor O-ring for cracks or leaks.

2.Replace the O-ring if it is worn or damaged.

3.Lubricate the new O-ring with engine oil.

4.Install the lubricated O-ring.

Installation Procedure

1.Install the CKP sensor in the engine block.

2.Install the CKP sensor mounting bolt.

Tighten

DTighten the mounting bolt to 9 N·m (0.9kg·m/78

lb in.).

TS22909

3.Connect the electrical connector to the CKP sensor.

4.Connect the negative battery cable.

Engine Coolant Temperature

(ECT) Sensor

Removal Procedure

NOTE:Care must be taken when handling the engine

coolant temperature (ECT) sensor. Damage to the ECT

sensor will affect proper operation of the fuel injection

system.

1.Disconnect the negative battery cable.

2.Drain the radiator coolant. Refer to

Draining and

Refilling Cooling System

Engine Cooling

3.Disconnect the electrical connector.

014RW127

4.Remove the ECT sensor from the coolant crossover.

014RW086

Installation Procedure

1.Apply sealer or the equivalent to the threads of the

ECT sensor.

2.Install the ECT sensor in the coolant crossover.

Tighten

DTighten the ECT sensor to 30 N·m (3.1kg·m/22

lb ft.).

014RW086

3.Connect the electrical connector.

014RW085

4.Fill the radiator with coolant. Refer to

Draining and

Refilling Cooling System

Engine Cooling

5.Connect the negative battery cable.

Heated Oxygen Sensor (HO2S)

Removal Procedure

1.Disconnect the negative battery cable.

2.Locate the four oxygen sensors.

060RX087

DBank 1 sensor 1 is mounted on the exhaust pipe

ahead of the right-hand catalytic converter.

TS22912

DBank 2 sensor 1 is mounted on the exhaust pipe

ahead of the left-hand catalytic converter.

TS22914

3.Disconnect the pigtail from the wiring harness.

IMPORTANT:The pigtail is permanently attached to

the sensor. Be careful not to pull the wires out.

NOTE: Do not use a torch to remove an HO2S unless the

sensor is being replaced. Using a torch could damage the

sensor.

4.Remove the sensor from the exhaust pipe.

DBecause of the expansion and contraction of the

metal in the exhaust system over time, this may be

difficult if the engine temperature is below 48°C

(120°F).

TS23739

Inspection Procedure

All four sensors are identical. Inspect each in the same

way.

1.Inspect the pigtail and the electrical connector for

grease, dirt, corrosion, and bare wires or worn

insulation.

2.Inspect the louvered end of the sensor for grease,

dirt, or other contaminations.

TS23739

Installation Procedure

IMPORTANT:

DNew or service sensors will already have the

compound applied to the threads. If a sensor is

removed and is to be reinstalled for any reason, the

threads must have anti-seize compound applied.

1.Apply anti-seize compound or the equivalent to the

threads of the oxygen sensor, if necessary.

2.Install the oxygen sensor on the exhaust pipe in its

original position.

Tighten

DTighten the oxygen sensor to 55 N·m

(5.6kg·m/40 lb in.).

TS23739

3.Connect the pigtail to the wiring harness.

4.Connect the negative battery cable.

Intake Air Temperature (IAT)

Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Remove the engine cover

3.The IAT sensor is located in the intake air duct, behind

the throttle body.

4.Disconnect the electrical connector from the IAT

sensor.

TS23741

5.Remove the IAT sensor from the intake air duct by

using a rocking motion while pulling the sensor.

Installation Procedure

1.Install the IAT sensor into the grommet in the intake

air duct.

2.Correct the IAT electrical connector.

TS23741

3.Install the engine cover.

4.Connect the negative battery cable.

Knock Sensor (KS)

Removal Procedure

1.Disconnect the negative battery cable.

2.Drain the cooling system. Refer to

Draining and

Filling the Cooling System

Engine Cooling

3.Remove the engine cover.

4.Remove the common chamber assembly.

Refer to Common Chamber in Engine Mechaical.

014RW106

5.Disconnect the electrical connector from the knock

sensor.

014RW103

6.Unscrew the knock sensor from the engine block.

Installation Procedure

NOTE:Do not apply thread sealant to the sensor threads.

The sensor is coated at the factory and applying

additional sealant will affect the sensor’s ability to detect

detonation.

1.Screw the knock sensor into the engine block.

Tighten

DTighten the knock sensor to 20 N·m

(2.0kg·m/177 lb in.).

014RW103

2.Connect the electrical connector to the knock sensor.

3.Install the common chamber assembly.

Refer to Common Chamber in Engine Mechanical.

014RW106

4.Install the engine cover.

5.Fill the cooling system.

Refer to Draining and Filling the Cooling System in

Engine Cooling.

6.Connect the negative battery cable.

Mass Air Flow (MAF) Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the electrical connector from the MAF

sensor.

TS23740

3.Loosen the clamps which secure the intake air duct

and the air cleaner to the MAF sensor.

4.Remove the intake air duct from the MAF sensor.

5.Remove the MAF sensor from the air cleaner.

TS23781

Installation Procedure

1. Install the MAF sensor on the air cleaner with the

clamp.

2.Install the intake air duct and the clamp on the MAF

sensor.

TS23781

3.Tighten the clamps to secure the MAF sensor to the

intake air duct and the air cleaner.

4.Connect the MAF electrical connector.

5.Connect the negative battery cable.

Manifold Absolute Pressure

(MAP) Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the electrical connector from the MAP

sensor.

055RW005

3.Remove the bolt securing the MAP sensor to the

mounting bracket on the common chamber.

4.Remove the MAP sensor from the mounting bracket.

055RW002

Installation Procedure

1.Install the MAP sensor in the mounting bracket.

2.Install the mounting bracket retaining bolt on the

common chamber.

3.Connect the MAP electrical connector.

055RW005

4.Connect the negative battery cable.

Malfunction Indicator Lamp

(MIL)

Removal and Installation Procedure

Refer to Warning light bulb, indicator light valve,

illumination light bulb, A/T indicator light bulb in Meter and

Gauge.

Powertrain Control Module

(PCM)

Service Precaution

NOTE:To prevent possible electrostatic discharge

damage to the PCM, do not touch the connector pins or

soldered components on the circuit board.

Electrostatic Discharge (ESD)

Damage

Electronic components used in the control systems are

often designed to carry very low voltage. Electronic

components are susceptible to damage caused by

electrostatic discharge. Less than 100 volts of static

electricity can cause damage to some electronic

components. By comparison, it takes as much as 4,000

volts for a person to even feel the zap of a static

discharge.

There are several ways for a person to become statically

charged. The most common methods of charging are by

friction and by induction. An example of charging by

friction is a person sliding across a car seat.

Charging by induction occurs when a person with well

insulated shoes stands near a highly charged object and

momentarily touches ground. Charges of the same

polarity are drained off leaving the person highly charged

with the opposite polarity. Static charges can cause

damage, therefore, it is important to use care when

handling and testing electronic components.

NOTE:To prevent possible Electrostatic Discharge

damage, follow these guidelines:

DDo not touch the control module connector pins or

soldered components on the control module circuit

board.

DDo not open the replacement part package until the

part is ready to be installed.

DBefore removing the part from the package, ground

the package to a known good ground on the vehicle.

DIf the part has been handled while sliding across the

seat, or while sitting down from a standing position, or

while walking a distance, touch a known good ground

before installing the part.

NOTE:To prevent internal PCM damage, the ignition

must be in the “OFF” position in order to disconnect or

reconnect power to the PCM (for example: battery cable,

PCM pigtail, PCM fuse, jumper cables, etc.).

IMPORTANT:When replacing the production PCM

with a service PCM, it is important to transfer the

broadcast code and production PCM number to the

service PCM label. This will allow positive identification of

PCM parts throughout the service life of the vehicle. Do

not record this information on the metal PCM cover.

IMPORTANT:The ignition should always be in the

“OFF” position in order to install or remove the PCM

connectors.

Removal Procedure

1.Disconnect the negative battery cable.

2.Block the wheels.

3.Remove the two screws attaching the rear console

and lift the upward rear console, then disconnect the

switch connector.

4. Remove the lower cluster assembly by pulling the

cover toward the rear.

5.Remove the transfer knob.

6.Remove the six screws attaching the upper console

and front console.

745RX008

7.Disconnect the red, white, and blue electrical

connectors at the PCM.

8.Remove the two screws in the front of the PCM.

9.Remove the one screws at the left rear of the PCM.

10.Pull the PCM straight out from the dashboard.

014RW111

Installation Procedure

1.Insert the PCM into the dashboard.

DLine up the holes in front for the mounting screws.

2.Install the PCM with two screws in the front and one

screw at the left rear.

3.Plug the red, white, and blue connectors into the

appropriate sockets.

014RW111

4.Install the front console and lower console.

5.Install the transfer knob.

6.Connect the switch connector and install the rear

console.

745RX008

If the PCM is replaced, the new PCM will need to be

programmed.

EEPROM

General Description

The Electronically Erasable Programmable Read Only

Memory (EEPROM) is a permanent memory that is

physically soldered within the PCM. The EEPROM

contains program and calibration information that the

PCM needs to control powertrain operation.

Functional Check

1.Perform the On-Board Diagnostic System Check.

2.Start the engine and run for one minute.

3.Scan for DTCs using the Tech 2.

Throttle Position (TP) Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the TPS electrical connector.

3.Remove the bolts and the TP sensor from the throttle

body.

TS23747

NOTE:Do not clean the TP sensor by soaking it in

solvent. The sensor will be damaged as a result.

Function Check

Use a Tech 2 to check the TP sensor output voltage at

closed throttle.

DThe voltage should be under 0.85 volt.

DIf the reading is greater than 0.85 volt, check the

throttle shaft to see if it is binding. Check that the

throttle cable is properly adjusted, also. Refer to

Throttle Cable Adjustment

- Section 6E1.

DIf the throttle shaft is not binding and the throttle cable

is properly adjusted, install a new TP sensor.

Installation Procedure

1.Install the TP sensor on the throttle body with the

bolts.

TS23747

2.Connect the TP electrical connector.

3.Install the negative battery cable.

Vehicle Speed Sensor (VSS)

Removal Procedure

CAUTION:The VSS is located on the right side of

the transfer case just ahead of the rear propeller

shaft and very close to the exhaust pipes. Be sure

that the exhaust pipes are cool enough to touch

before trying to remove the VSS. If the pipes are hot,

you could be burned.

1.Disconnect the negative battery cable.

2.Disconnect the VSS electrical connector.

TS23748

3.Remove the bolt and the clamp securing the VSS in

place.

IMPORTANT:Have a container ready to catch any fluid

that leaks out when the VSS is removed from the transfer

case.

TS23780

4.Remove the VSS from the transfer case by wiggling it

slightly and pulling it straight out.

Inspection Procedure

1.Inspect the electrical connector for signs of corrosion

or warping. Replace the VSS if the electrical

connector is corroded or warped.

2.Inspect the VSS driven gear for chips, breaks, or worn

condition. Replace the VSS if the driven gear is

chipped, broken or worn.

3.Inspect the O-ring for wear, nicks, tears, or

looseness. Replace the O-ring if necessary.

Installation Procedure

1.Install the VSS in the transfer case with the notch for

the connector facing the rear.

2.Secure the VSS in place with the clamp and the bolt.

Tighten

DTighten the bolt to 16 N·m (1.6 kg·m/12 lb ft.).

TS23780

3.Connect the VSS electrical connector.

TS23748

4.Check the transfer case oil level. Add fluid if

necessary.

5.Connect the negative battery cable.

Air Cleaner/Air Filter

Removal Procedure

1.Loosen the clamp between the air cleaner lid and the

mass air flow sensor.

2.Release the four latches securing the lid to the air

cleaner housing.

3.Remove the air cleaner lid.

TS23973

4.Remove the air filter element.

TS23794

5.Remove the retaining bolts and the air cleaner

housing from the vehicle.

130RT002

Installation Procedure

1.Install the air cleaner housing in the vehicle with the

retaining bolts.

130RT002

2.Install the air filter element in the air cleaner housing.

TS23794

3.Install the air cleaner lid on the MAF sensor and the air

cleaner housing.

TS23973

4.Tighten the clamp and secure the four latches

between the lid and the air cleaner housing.

Idle Air Control (IAC) Valve

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the IAC electrical connector.

3.Remove the bolts and the IAC valve from the throttle

body.

NOTE: Do not clean the IAC valve by soaking it in

solvent. The valve will be damaged as a result.

TS23745

Cleaning, Inspection, and Measure-

ment Procedure

DClean the IAC valve O-ring sealing surface, pintle

valve seat and air passage.

– Use carburetor cleaner and a parts cleaning brush

to remove carbon deposits. Do not use a cleaner

that contains methyl ethyl ketone. This is an

extremely strong solvent and not necessary for this

type of deposit.

– Shiny spots on the pintle are normal and do not

indicate misalignment or a bent pintle shaft.

– If the air passage has heavy deposits, remove the

throttle body for complete cleaning.

TS23746

DInspect the IAC valve O-ring for cuts, cracks, or

distortion. Replace the O-ring if damaged.

DIn order to install a new IAC valve, measure the

distance between the tip of the pintle and the

mounting flange. If that measurement is 28 mm (1.1

in.) or less, the valve needs no adjustment. If the

measurement is greater than 28 mm (1.1 in.), apply

finger pressure and retract the valve. The force

required to retract the pintle on a new valve will not

damage the valve, shaft, or pintle.

NOTE:Do not push or pull on the IAC valve pintle on IAC

valves that have been in service. The force required to

move the pintle may damage it.

IMPORTANT:Use an identical replacement part in

order to replace a valve. IAC valve pintle shape and

diameter are designed for the specific application.

TS23746

Installation Procedure

1.Install the IAC valve on the throttle body with the bolts.

TS23745

2.Connect the IAC valve electrical connector.

3.Install the negative battery cable.

Common Chamber

Removal and Installation Prodedure

Refer to Common Chamber in Engine Mechanical.

Accelerator Cable Assembly

Removal Procedure

1.Remove the engine cover.

2.Loosen the adjusting nut on the cable bracket

mounting on the common chamber.

101RW005

3.Remove the accelerator control cable (on the throttle

valve end).

101RW006

4.Remove the accelerator control cable (on the

accelerator pedal end).

TS23982

5.Remove the grommet.

6.Remove the accelerator control cable.

TS23983

Inspection Procedure

Check the following items, and replace the control cable if

any abnormality is found:

DThe control cable should move smoothly.

DThe control cable should not be bent or kinked.

DThe control cable should be free of damage and

corrosion.

Installation Procedure

1.Install the accelerator control cable.

TS23983

2.Install the grommet.

3.Install the accelerator control cable (on the

accelerator pedal end).

TS23982

4.Install the accelerator control cable (on the throttle

valve end).

101RW006

5.Install the adjusting nut.

101RW007

6.Adjust the accelerator cable at the throttle body.

Refer to

Accelerator Cable Adjustment

- Section 6E1.

7.Install the engine cover.

Adjustment Procedure

1.Loosen the adjusting nut and lock nut.

2.Pull outer cable closing fully the throttle valve.

3.Tighten adjusting nut and lock nut temporarily.

035RW004

4.Loosen adjusting nut by three turns and tighten lock

nut. Then, manually operating the throttle valve,

make sure that the valve lever returns up to the

stopper screw.

IMPORTANT:The valve lever must return up to the

stopper screw. If the valve lever does not reach the

stopper screw, repeat the procedure again from step 1.

5.It does not reach the stopper screw , repeat from step

TS23782

Accelerator Pedal Replacement

Removal Procedure

1.Disconnect the cruise control cable from the

accelerator pedal assembly.

TS24053

2.Disconnect the accelerator pedal control cable from

the accelerator pedal assembly.

TS24054

3. Disconnect the wiring harness from the kick-down

switch.

TS24038

4.Remove the two screws from the accelerator pedal

assembly.

TS24055

5.Remove the accelerator pedal assembly from the

bulkhead.

Installation Procedure

1.Install the accelerator pedal assembly on the

bulkhead.

2.Install the two screws to the accelerator pedal

assembly.

TS24055

3.Connect the wiring harness to the kick-down switch.

TS24038

4. Connect the accelerator pedal control cable to the

accelerator pedal assembly.

TS24054

5.Connect the cruise control cable to the accelerator

pedal assembly.

TS24053

Pedal Stroke Adjustment Procedure

1.Loosen the jam nut and rotate the kick-down switch

counterclockwise.

TS24039

2.Fully depress the pedal and hold it by hand. Rotate

the switch clockwise until the switch clicks.

3.Rotate the switch 1/2 turn further and lock it in this

position by tightening the jam nut.

TS24040

4.Step on the accelerator pedal and make sure there is

a clicking sound at the full-stroke position.

Fuel Fillter Cap

General Description

The fuel filler cap includes a vacuum valve and a pressure

valve.

If high vacuum or high pressure occurs in the fuel tank,

each valve works to adjust the pressure in order to

prevent damage to the tank at the EGR valve.

TS23767

Inspection Procedure

NOTE: Replace the fuel filler cap with the same type of

filler cap that was originally installed on the vehicle.

DCheck the seal ring in the filler cap for any abnormality

and for seal condition.

DReplace the filler cap if any abnormality is found.

Fuel Filter

Removal Procedure

1.Disconnect the negative battery cable.

2.Remove the fuel filler cap.

041RW005

3.Disconnect the fuel line from the fuel filter on the

engine side.

4.Disconnect the fuel line from the fuel filter on the fuel

tank side.

041RW006

5.Remove the bolt on the fuel filter holder.

041RW007

6.Remove the fuel filter.

041RW008

Inspection Procedure

1.Replace the fuel filter when the following occur:

DFuel leaks from the fuel filter body.

DThe fuel filter body is damaged.

DThe fuel filter is clogged with dirt or sediment.

2.If the drain hole is clogged, clean the drain.

041RW009

Installation Procedure

1.Install the fuel filter in the correct direction.

041RW008

2.Install the bolt on the fuel filter holder.

041RW007

3.Connect the fuel line on the engine side.

4.Connect the fuel line on the fuel tank side.

041RW006

5.Install the fuel filler cap.

041RW005

6.Connect the negative battery cable.

Fuel Gauge Unit

Removal Procedure

Refer to

Fuel Gauge Unit In Engine Fuel.

014RW133

Fuel Injectors

Removal Procedure

NOTE:If the fuel injectors are leaking, the engine oil may

be contaminated with fuel. Check the oil for signs of

contamination and change the oil and the filter if

necessary.

NOTE:Use care in removing the fuel injectors in order to

prevent damage to the fuel injector electrical connector

pins or the fuel injector nozzles. The fuel injector is an

electrical component and should not be immersed in any

type of cleaner as this may damage the fuel injector.

IMPORTANT:Fuel injectors are serviced as a complete

assembly only.

1.Disconnect the negative battery cable.

2.Remove the upper intake manifold. Refer to

Common Chamber in Engine Mechanical.

3.Remove the fuel rail. Refer to

Fuel Rail

014RW106

4.Remove the injector retainer clip.

F06RW017

5.Remove the fuel injector assembly.

6.Remove the O-ring from the fuel injector.

7.Remove the O-ring backup from the fuel injector .

Inspection Procedure

1.Inspect the O-rings for cracks or leaks.

2.Replace worn or damaged O-rings.

3.Lubricate the new O-rings with engine oil before

installation.

Installation Procedure

1.Install the O-ring backup on the fuel injector.

2.Install the new O-ring on the fuel injector.

3.Install the fuel injector on the fuel rail.

F06RW017

4.Use new fuel injector retainer clips to retain the fuel

injector to the fuel rail.

5.Coat the end of the fuel injector with engine oil.

6.Install the fuel rail. Refer to

Fuel Rail

014RW106

7.Install the upper intake manifold. Refer to

Common

Chamber in Engine Mechanical.

8.Install the engine cover.

9.Connect the negative battery cable.

Fuel Pressure Regulator

Removal Procedure

CAUTION:To reduce the risk of fire and personal

injury, it is necessary to relieve the fuel system

pressure before servicing the fuel system

components.

CAUTION:After relieving the system pressure, a

small amount of fuel may be released when servicing

fuel lines or connections. Reduce the chance of

personal injury by covering the fuel line fittings with

a shop towel before disconnecting the fittings. The

towels will absorb any fuel that may leak out. When

the disconnect is completed, place the towel in an

approved container.

NOTE:Compressed air must never be used to test or

clean a fuel pressure regulator, as damage to the fuel

pressure regulator may result.

NOTE:To prevent damage to the fuel pressure regulator,

do not immerse the pressure regulator in solvent.

1.Depressurize the fuel system. Refer to

Fuel Pressure

Relief Procedure

2.Disconnect the negative battery cable.

3.Remove the fuel pump relay. Refer to

Fuel Pump Relay

4. Remove the pressure regulator hose from the fuel

pressure regulator.

014RW110

5.Remove the two bolts from the protector that secures

the common chamber.

014RW109

6.Remove the fuel pressure regulator attaching screw.

F06RW016

7.Remove the fuel pressure regulator from the fuel rail.

Disassembly Procedure

1.Remove the O-ring from the fuel pressure regulator.

2.Loosen the swivel nut.

3. Remove the fuel return line from the fuel pressure

regulator.

4.Remove the O-ring from the fuel return line.

DThe O-ring may be left inside the fuel pressure

regulator instead of on the fuel return line.

F06RW016

Assembly Procedure

1.Install a new O-ring on the fuel return line.

2.Install the fuel return line on the fuel pressure

regulator.

NOTE: Do not over-tighten the swivel nut on the fuel

pressure regulator. The fuel pressure regulator can be

damaged and fuel may leak if the swivel nut is

over-tightened.

3.Tighten the swivel nut.

4.Install a new O-ring on the fuel pressure regulator.

Installation Procedure

1.Install the fuel pressure regulator attaching screw.

Tighten

DTighten the fuel pressure regulator attaching

screw to 3 N·m (0.3kg·m/26 lb in.).

F06RW016

2.Install the fuel pressure regulator on the fuel rail.

3.Install the two bolts to the protector that secures the

common chamber.

014RW109

4.Install the pressure regulator hose to the fuel

pressure regulator.

014RW110

5.Install the fuel pump relay. Refer to

Fuel Pump Relay

6.Connect the negative battery cable.

7.Crank the engine until it starts. Cranking the engine

may take longer than usual due to trapped air in the

fuel lines.

Fuel Metering System

Fuel Pressure Relief Procedure

CAUTION:To reduce the risk of fire and personal

injury, it is necessary to relieve the fuel system

pressure before servicing the fuel system

components.

CAUTION:After relieving the system pressure, a

small amount of fuel may be released when servicing

fuel lines or connections. Reduce the chance of

personal injury by covering the fuel line fittings with

a shop towel before you disconnect the fittings. The

towels will absorb any fuel that may leak out. When

the disconnect is completed, place the towel in an

approved container.

1.Remove the fuel cap.

2.Remove the fuel pump relay from the underhood

relay box. Refer to

Fuel Pump Relay

014RW089

3.Start the engine and allow it to stall.

4.Crank the engine for 30 seconds.

5.Disconnect the negative battery cable.

Fuel Pump Assembly

Removal Procedure

Refer to

Fuel Tank In Fuel Pump Relay.

014RW133

Fuel Pump Relay

Removal Procedure

1.Remove the fuse and relay box cover from under the

hood.

2.Consult the diagram on the cover to determine which

is the correct relay.

3.Pull the relay straight up and out of the fuse and relay

box.

014RW089

Installation Procedure

1.Insert the relay into the correct place in the fuse and

relay box with the catch slot facing forward.

014RW089

2.Press down until the catch engages.

DAn audible “click” will be heard.

3.Install the fuse and relay box cover.

Fuel Rail Assembly

Removal Procedure

NOTE:

DDo not attempt to remove the fuel inlet fitting on the

fuel rail. It is staked in place. Removing the fuel inlet

fitting will result in damage to the fuel rail or the

internal O-ring seal.

DUse care when removing the fuel rail assembly in

order to prevent damage to the injector electrical

connector terminals and the injector spray tips.

DFittings should be capped and holes plugged during

servicing to prevent dirt and other contaminants from

entering open lines and passages.

IMPORTANT:An eight-digit identification number is

stamped on the side of the fuel rail. Refer to this number

when you service the fuel rail or when a replacement part

is required.

TS24022

Before removal, the fuel rail assembly may be cleaned

with a spray type engine cleaner. Follow the spray

package instructions. Do not immerse the fuel rails in

liquid cleaning solvent.

1.Depressurize the fuel system. Refer to Fuel Pressure

Relief Procedure in this Section.

2.Disconnect the negative battery cable.

3.Remove the engine cover.

4.Disconnect the accelerator pedal cable from throttle

body and cable bracket.

5. Disconnect the connectors from manifold absolute

pressure sensor, solenoid valve, electric vacuum

sensing valve.

6.Disconnect the vacuum hose on canister VSV and

positive crankcase ventilation hose.

7.Remove the common chamber Refer to the Common

Chamber in Engine Mechanical.

1. Lift up carefully on the fuel injectors. Do not

separate the fuel injectors from the fuel rail.

2.If an injector becomes separated from the fuel

rail, the infector O-ring seals and the retainer clip

must be replaced.

3.Drain residual fuel into an approved container.

014RW106

8.If removal of the fuel pressure regulator is necessary,

refer to

Fuel Pressure Regulator

9.If removal of the fuel injectors is necessary, refer to

Fuel Injectors

Installation Procedure

1.If the fuel injectors were removed, install them. Refer

Fuel Injectors

2.If the fuel pressure regulator was removed, install it.

Refer to

Fuel Pressure Regulator

3.Install the common chamber.Refer to common

chamber in engine Mechanical.

014RW106

4.Connect the vacuum hose on Canister VSV and

positive crankcase ventilation hose.

5.Connect the connectors to manifold absolute

pressure sensor, solenoid valve, electric vacuum

sensing valve.

6.Connect the accelerator pedal cable to throttle body

and cable bracket.

7.Install the engine cover.

8.Connect the negative battery cable.

9.Crank the engine until it starts. Cranking the engine

may take longer than usual due to trapped air in the

fuel rail and in the injectors.

Fuel Tank

Removal Procedure

Refer to

Fuel Tank In Fuel Pump Relay.

014RW134

Throttle Body (TB)

Removal Procedure

1.Disconnect the negative battery cable.

2.Drain the cooling system. Refer to

Cooling System

3.Remove the accelerator cable assembly.

4.Disconnect the electrical connectors:

DThrottle position (TP) sensor.

DIdle air control (IAC) solenoid.

DIntake air temperature (IAT) sensor. Refer to

Intake

Air Temperature Sensor

035RW023

5.Disconnect the vacuum hose below the air horn.

6.Remove the intake air duct clamp.

7.Disconnect the intake air duct.

8.Disconnect the coolant lines from the throttle body.

9.Remove the bolts from the common chamber.

10.Remove the throttle body from the common chamber.

11.Remove the gasket from the upper intake manifold.

035RW024

12.Remove the IAC. Refer to

Idle Air Control (IAC)

Solenoid

13.Remove the TP sensor. Refer to

Throttle Position

(TP) Sensor

Inspection Procedure

NOTE:Do not use solvent of any type when you clean the

gasket surfaces on the intake manifold and the throttle

body assembly. The gasket surfaces and the throttle

body assembly may be damaged as a result.

DIf the throttle body gasket needs to be replaced,

remove any gasket material that may be stuck to the

mating surfaces of the manifold.

DDo not leave any scratches in the aluminum casting.

Installation Procedure

1.Install the TP sensor. Refer to

Throttle Position (TP)

Sensor

2.Install the IAC. Refer to

Idle Air Control (IAC)

Solenoid

3.Install the gasket on the common chamber.

4.Install the throttle body on the common chamber.

5.Secure the gasket and the throttle body with the four

bolts.

DThe vacuum lines must be properly routed under

the throttle body before tightening the mounting

bolts.

Tighten

DTighten the throttle body mounting bolts to 24

N·m (2.4kg·m/17 lb ft.).

035RW024

6.Install the coolant lines.

7.Connect all the vacuum lines.

8.Install the intake air duct.

9.Tighten the intake air duct clamp.

10.Connect all the electrical connectors:

DThrottle position (TP) sensor.

DIdle air control (IAC) solenoid.

DIntake air temperature (IAT) sensor. Refer to

Intake

Air Temperature Sensor

035RW023

11.Install the accelerator cable assembly.

12.Fill the cooling system. Refer to

Cooling System

13.Install the negative battery cable.

Electronic Ignition System

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the electrical connector at the coil

module.

3.Remove the two screws that secure the coil module to

the rocker cover.

014RW108

4.Remove the coil module and the spark plug boot from

the spark plug.

DTwist the coil module while pulling it straight up.

014RW091

5. Use the spark plug socket in order to remove the

spark plug from the engine.

Spark Plug Gap Check

DCheck the gap of all spark plugs before installation.

DUse a round wire feeler gauge to ensure an accurate

check.

DPlugs installed with the wrong gap can cause poor

engine performance and excessive emissions.

Installation Procedure

NOTE: The plug must thread smoothly into the cylinder

head and be fully seated. Use a thread chaser if

necessary to clean the threads in the cylinder head.

Cross-threading or failure to fully seat the spark plug can

cause plug overheating, exhaust blow-by gases, or

thread damage. Do not overtighten the spark plugs. Over

tightening can cause aluminum threads to strip.

1.Install the spark plug in the engine. Use the

appropriate spark plug socket.

Tighten

DTighten the spark plug to 18 N·m (1.8kg·m/13 lb

ft.).

2.Install the coil module and spark plug boot over the

spark plug.

014RW108

3.Secure the coil module to the rocker cover with two

screws.

014RW091

4.Connect the electrical connector at the coil module.

5.Connect the negative battery cable.

Catalytic Converter

Removal and Installation Procedure

Refer to

Engine Exhaust in Engine

Air Conditioning Relay

Removal Procedure

1.Remove the fuse and relay box cover from under the

hood.

2.Consult the diagram on the cover to determine which

is the correct relay.

3.Pull the relay straight up and out of the fuse and relay

box.

014RW090

Installation Procedure

1.Insert the relay into the correct place in the fuse and

relay box with the catch slot facing forward.

2.Press down until the catch engages.

DAn audible “click” will be heard.

3.Install the fuse and relay box cover.

EVAP Canister Hoses

Service Information

To view the routing of the EVAP canister hoses, refer to

Vehicle Emission Control Information

Diagnosis

. Use

6148M or equivalent when you replace the EVAP canister

hoses.

EVAP Canister

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the two hoses from the EVAP canister.

3.Disconnect the fuel vapor connector and the purge

hose from the EVAP canister vent solenoid.

014RW130

4.Remove the two retaining bolts the EVAP canister to

the mounting bracket on the cross member.

014RW131

5.Remove the retaining bolt on the mounting bracket

the slide the canister out of mounting bracket.

014RW129

Inspection Procedure

1.Inspect the hoses for cracks and leaks.

2.Inspect the canister for a damaged case.

Installation Procedure

1.Slide the canister into mounting bracket the install the

mounting bracket bolt.

014RW129

2. Install the retaining bolts the EVAP canister to the

mounting bracket on the cross member.

014RW131

3.Connect the fuel vapor connector to the EVAP

canister vent solenoid.

4.Connect the two hoses to the EVAP canister.

014RW130

5.Disconnect the negative battery cable.

EVAP Canister Purge Solenoid

Removal Procedure

1.Disconnect the electrical connector from the EVAP

canister purge solenoid.

2.Disconnect the vacuum hoses from the EVAP

canister purge solenoid.

014RW136

3.Remove the EVAP canister purge solenoid retaining

bolt from the upper intake manifold.

4.Remove the EVAP canister purge solenoid.

014RW137

Installation Procedure

1.Install the EV AP canister purge solenoid on the upper

intake manifold.

2.Install the EVAP canister purge solenoid retaining

bolt.

3.Connect the vacuum hoses to the EVAP canister

purge solenoid.

014RW137

4.Connect the electrical connector to the EVAP canister

purge solenoid.

014RW138

Fuel Tank Vent Valve

Removal and Installation Procedure

Refer to

Fuel Pump

Linear Exhaust Gas

Recirculation (EGR) Valve

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the electrical connector at the EGR valve.

014RW139

3.Remove the bolt and the nut from the upper intake

manifold.

014RW098

4.Remove the EGR valve from the upper intake

manifold.

5.Remove the gasket from the upper intake manifold.

Installation Procedure

1.Install the gasket on the upper intake manifold.

2.Install the EGR valve on the upper intake manifold.

3.Secure the EGR valve and the gasket with the bolt

and the nut.

NOTE: It is possible to install the EGR valve rotated 180°

from the correct position. Make sure that the base of the

valve is placed so that it aligns with the mounting flange.

014RW098

4.Connect the electrical connector at the EGR valve.

014RW139

5.Connect the negative battery cable.

Positive Crankcase Ventilation

(PCV) Valve

Removal Procedure

1.Remove the vacuum hose at the PCV valve.

DSlide the clamp back to release the hose.

2.Pull the PCV valve from the rubber grommet in the

right valve cover.

014RW097

Inspection Procedure

1.Shake the valve and listen for the rattle of the needle

inside the valve.

2.If the valve does not rattle, replace the valve.

Installation Procedure

1.Push the PCV valve into the rubber grommet in the

left valve cover.

2.Install the vacuum hose on the PCV valve and secure

the vacuum hose with the clamp.

014RW097

Wiring and Connectors

Wiring Harness Service

The control module harness electrically connects the

control module to the various solenoids, switches and

sensors in the vehicle engine compartment and

passenger compartment.

Replace wire harnesses with the proper part number

replacement.

Because of the low amperage and voltage levels utilized

in powertrain control systems, it is essential that all wiring

in environmentally exposed areas be repaired with crimp

and seal splice sleeves.

The following wire harness repair information is intended

as a general guideline only. Refer to

Chassis Electrical

for

all wire harness repair procedures.

Connectors and Terminals

Use care when probing a connector and when replacing

terminals. It is possible to short between opposite

terminals. Damage to components could result. Always

use jumper wires between connectors for circuit

checking. NEVER probe through Weather-Pack seals.

Use an appropriate connector test adapter kit which

contains an assortment of flexible connectors used to

probe terminals during diagnosis. Use an appropriate

fuse remover and test tool for removing a fuse and to

adapt the fuse holder to a meter for diagnosis.

Open circuits are often difficult to locate by sight because

oxidation or terminal misalignment are hidden by the

connectors. Merely wiggling a connector on a sensor , or

in the wiring harness, may temporarily correct the open

circuit. Intermittent problems may also be caused by

oxidized or loose connections.

Be certain of the type of connector/terminal before

making any connector or terminal repair. Weather-Pack

and Com-Pack III terminals look similar , but are serviced

differently.

PCM Connectors and Terminals

Removal Procedure

1.Remove the connector terminal retainer.

2.Push the wire connected to the affected terminal

through the connector face so that the terminal is

exposed.

3.Service the terminal as necessary.

Installation Procedure

1.Bend the tab on the connector to allow the terminal to

be pulled into position within the connector.

2.Pull carefully on the wire to install the connector

terminal retainer.

Wire Harness Repair: Twisted

Shielded Cable

Removal Procedure

1.Remove the outer jacket.

2.Unwrap the aluminum/mylar tape. Do not remove the

mylar.

047

3.Untwist the conductors.

4.Strip the insulation as necessary.

048

Installation Procedure

1.Splice the wires using splice clips and rosin core

solder.

2.Wrap each splice to insulate.

3.Wrap the splice with mylar and with the drain

(uninsulated) wire.

049

4.Tape over the whole bundle to secure.

050

Twisted Leads

Removal Procedure

1.Locate the damaged wire.

2.Remove the insulation as required.

051

Installation Procedure

1.Use splice clips and rosin core solder in order to splice

the two wires together.

052

2.Cover the splice with tape in order to insulate it from

the other wires.

053

3.Twist the wires as they were before starting this

procedure.

054

4.Tape the wires with electrical tape. Hold in place.

055

Weather-Pack Connector

Tools Required

5–8840–6632–0 Weather-Pack II Terminal Remover

Removal Procedure

A Weather-Pack connector can be identified by a rubber

seal at the rear of the connector. This engine room

connector protects against moisture and dirt, which could

from oxidation and deposits on the terminals. This

protection is important, because of the low voltage and

the low amperage found in the electronic systems.

1.Open the secondary lock hinge on the connector.

070

2.Use tool 5–8840–6632–0 or the equivalent to remove

the pin and the sleeve terminals. Push on

5–8840–6632–0 to release.

NOTE: Do the use an ordinary pick or the terminal may

be bent or deformed. Unlike standard blade terminals,

these terminals cannot be straightened after they have

been improperly bent.

071

3.Cut the wire immediately behind the cable seal.

072

Installation Procedure

Make certain the connectors are properly seated and all

of the sealing rings are in place when you reconnect the

leads. The secondary lock hinge provides a backup

locking feature for the connector. The secondary lock

hinge is used for added reliability. This flap should retain

the terminals even if the small terminal lock tangs are not

positioned properly.

Do not replace the Weather-Pack connections with

standard connections. Read the instructions provided

with the Weather-Pack connector and terminal packages.

1.Replace the terminal.

2.Slip the new seal onto the wire.

3.Strip 5 mm (0.2”) of insulation from the wire.

4.Crimp the terminal over the wire and the seal.

073

5.Push the terminal and the connector to engage the

locking tangs.

070

6.Close the secondary locking hinge.

Com-Pack III

General Information

The Com-Pack III terminal looks similar to some

Weather-Pack terminals. This terminal is not sealed and

is used where resistance to the environment is not

required. Use the standard method when repairing a

terminal. Do not use the Weather-Pack terminal tool

5–8840–6632–0 or equivalent. These will damage the

terminals.

Metri-Pack

Tools Required

5–8840–0632–0 Terminal Remover

Removal Procedure

Some connectors use terminals called Metri-Pack Series

150. These may be used at the engine coolant

temperature (ECT) sensor.

1.Slide the seal (1) back on the wire.

2. Insert the 5–8840–0632–0 tool or equivalent (3) in

order to release the terminal locking tang (2).

060

3.Push the wire and the terminal out through the

connector. If you reuse the terminal, reshape the

locking tang.

Installation Procedure

Metri-Pack terminals are also referred to as “pull-to-seat”

terminals.

1.In order to install a terminal on a wire, the wire must be

inserted through the seal (2) and through the

connector (3).

2.The terminal (1) is then crimped onto the wire.

061

3.Then the terminal is pulled back into the connector to

seat it in place.

General Description (PCM and

Sensors)

58X Reference PCM Input

The powertrain control module (PCM) uses this signal

from the crankshaft position (CKP) sensor to calculate

engine RPM and crankshaft position at all engine speeds.

The PCM also uses the pulses on this circuit to initiate

injector pulses. If the PCM receives no pulses on this

circuit, DTC P0337 will set. The engine will not start and

run without using the 58X reference signal.

A/C Request Signal

This signal tells the PCM when the A/C mode is selected

at the A/C control head. The PCM uses this to adjust the

idle speed before turning “ON” the A/C clutch. The A/C

compressor will be inoperative if this signal is not

available to the PCM.

Refer to

A/C Clutch Circuit Diagnosis

for A/C wiring

diagrams and diagnosis for the A/C electrical system.

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor provides a signal

used by the powertrain control module (PCM) to calculate

the ignition sequence. The CKP sensor initiates the 58X

reference pulses which the PCM uses to calculate RPM

and crankshaft position.

Refer to

Electronic Ignition System

for additional

information.

0013

Camshaft Position (CMP) Sensor and

Signal

The camshaft position (CMP) sensor sends a CMP signal

to the PCM. The PCM uses this signal as a “syncpulse” to

trigger the injectors in the proper sequence. The PCM

uses the CMP signal to indicate the position of the #1

piston during its power stroke. This allows the PCM to

calculate true sequential fuel injection (SFI) mode of

operation. If the PCM detects an incorrect CMP signal

while the engine is running, DTC P0341 will set. If the

CMP signal is lost while the engine is running, the fuel

injection system will shift to a calculated sequential fuel

injection mode based on the last fuel injection pulse, and

the engine will continue to run. As long as the fault is

present, the engine can be restarted. It will run in the

calculated sequential mode with a 1-in-6 chance of the

injector sequence being correct.

Refer to

DTC P0341

for further information.

Engine Coolant Temperature (ECT) Sensor

The engine coolant temperature (ECT) sensor is a

thermistor (a resistor which changes value based on

temperature) mounted in the engine coolant stream. Low

coolant temperature produces a high resistance of

100,000 ohms at –40°C (–40°F). High temperature

causes a low resistance of 70 ohms at 130°C (266°F).

The PCM supplies a 5-volt signal to the ECT sensor

through resistors in the PCM and measures the voltage.

The signal voltage will be high when the engine is cold and

low when the engine is hot. By measuring the voltage, the

PCM calculates the engine coolant temperature. Engine

coolant temperature affects most of the systems that the

PCM controls.

The Tech 2 displays engine coolant temperature in

degrees. After engine start-up, the temperature should

rise steadily to about 85°C (185°F). It then stabilizes

when the thermostat opens. If the engine has not been

run for several hours (overnight), the engine coolant

temperature and intake air temperature displays should

be close to each other . A hard fault in the engine coolant

sensor circuit will set DTC P0117 or DTC P0118.

0016

Electrically Erasable Programmable Read

Only Memory (EEPROM)

The electrically erasable programmable read only

memory (EEPROM) is a permanent memory chip that is

physically soldered within the PCM. The EEPROM

contains the program and the calibration information that

the PCM needs to control powertrain operation.

Fuel Control Heated Oxygen Sensors

The fuel control heated oxygen sensors (Bank 1 HO2S 1

and Bank 2 HO2S 1) are mounted in the exhaust stream

where they can monitor the oxygen content of the exhaust

gas. The oxygen present in the exhaust gas reacts with

the sensor to produce a voltage output. This voltage

should constantly fluctuate from approximately 100 mV to

900 mV. The heated oxygen sensor voltage can be

monitored with a T ech 2. By monitoring the voltage output

of the oxygen sensor , the PCM calculates the pulse width

command for the injectors to produce the proper

combustion chamber mixture.

DLow HO2S voltage is a lean mixture which will result in

a rich command to compensate.

DHigh HO2S voltage is a rich mixture which will result in

a lean command to compensate.

An open Bank 1 HO2S 1 signal circuit will set a DTC

P0134 and the Tech 2 will display a constant voltage

between 400-500 mV. A constant voltage below 300 mV

in the sensor circuit (circuit grounded) will set DTC

P0131. A constant voltage above 800 mV in the circuit will

set DTC P0132. Faults in the Bank 2 HO2S 1 signal

circuit will cause DTC 0154 (open circuit), DTC P0151

(grounded circuit), or DTC P0152 (signal voltage high) to

set. The PCM can also detect HO2S response problems.

If the response time of an HO2S is determined to be too

slow, the PCM will store a DTC that indicates degraded

HO2S performance.

0012

Intake Air Temperature (IAT) Sensor

The intake air temperature (IAT) sensor is a thermistor

which changes its resistance based on the temperature of

air entering the engine. Low temperature produces a high

resistance of 100,000 ohms at –40°C (–40°F). High

temperature causes low resistance of 70 ohms at 130°C

(266°F) . The PCM supplies a 5-volt signal to the sensor

through a resistor in the PCM and monitors the signal

voltage. The voltage will be high when the incoming air is

cold. The voltage will be low when the incoming air is hot.

By measuring the voltage, the PCM calculates the

incoming air temperature. The IAT sensor signal is used

to adjust spark timing according to the incoming air

density.

The Tech 2 displays the temperature of the air entering

the engine. The temperature should read close to the

ambient air temperature when the engine is cold and rise

as underhood temperature increases. If the engine has

not been run for several hours (overnight), the IA T sensor

temperature and engine coolant temperature should read

close to each other. A fault in the IAT sensor circuit will set

DTC P0112 or DTC P0113.

Knock Sensor

Insufficient gasoline octane levels may cause detonation

in some engines. Detonation is an uncontrolled explosion

(burn) in the combustion chamber. This uncontrolled

explosion results from a flame front opposite that of the

normal flame front produced by the spark plug. The

rattling sound normally associated with detonation is the

result of two or more opposing pressures (flame fronts)

colliding within the combustion chamber. Light

detonation is sometimes considered normal, but heavy

detonation could result in engine damage.

A knock sensor system is used to control detonation. This

system is designed to retard spark timing up to 20

degrees to reduce detonation in the engine. This allows

the engine to use maximum spark advance to improve

driveability and fuel economy.

The knock sensor system has two major components:

DThe knock sensor (KS) module.

DThe knock sensor.

The knock sensor, mounted in the engine block near the

cylinders, detects abnormal vibration in the engine. The

sensor produces an AC output signal of about 10

millivolts. The signal amplitude and frequency are

dependent on the amount of knock being experienced.

The signal voltage increases with the severity of the

knock. This signal voltage is input to the PCM. The PCM

then retards the ignition control (IC) spark timing based

on the KS signal being received.

The PCM determines whether knock is occurring by

comparing the signal level on the KS circuit with the

voltage level on the noise channel. The noise channel

allows the PCM to reject any false knock signal by

indicating the amount of normal engine mechanical noise

present. Normal engine noise varies depending on the

engine speed and load. If the voltage level on the KS

noise channel circuit is below the range considered

normal, DTC P0327 will set, indicating a fault in the KS

circuit or the knock sensor. If the PCM determines that an

abnormal minimum or maximum noise level is being

experienced, DTC P0325 will set.

The PCM contains a knock sensor (KS) module. The KS

module contains the circuitry which allows the PCM to

utilize the KS signal and diagnose the KS sensor and the

KS circuitry. If the KS module is missing or faulty, a

continuous knock condition will be indicated, and the

PCM will set DTC P0325.

Although it is a plug-in device, the KS module is not

replaceable. If the KS module is faulty, the entire PCM

must be replaced.

0009

Linear Exhaust Gas Recirculation (EGR)

Control

The PCM monitors the exhaust gas recirculation (EGR)

actual position and adjusts the pintle position accordingly.

The PCM uses information from the following sensors to

control the pintle position:

DEngine coolant temperature (ECT) sensor.

DThrottle position (TP) sensor.

DMass air flow (MAF) sensor.

Mass Air Flow (MAF) Sensor

The mass air flow (MAF) sensor measures the difference

between the volume and the quantity of air that enters the

engine. “Volume” means the size of the space to be filled.

“Quantity” means the number of air molecules that will fit

into the space. This information is important to the PCM

because heavier, denser air will hold more fuel than

lighter, thinner air. The PCM adjusts the air/fuel ratio as

needed depending on the MAF value. The Tech 2 reads

the MAF value and displays it in terms of grams per

second (gm/s). At idle, the Tech 2 should read between

4-7 gm/s on a fully warmed up engine. Values should

change quickly on acceleration. Values should remain

stable at any given RPM. A failure in the MAF sensor or

circuit will set DTC P0101, DTC P0102, or DTC P0103.

0007

Manifold Absolute Pressure (MAP) Sensor

The manifold absolute pressure (MAP) sensor responds

to changes in intake manifold pressure (vacuum). The

MAP sensor signal voltage to the PCM varies from below

2 volts at idle (high vacuum) to above 4 volts with the

ignition ON, engine not running or at wide-open throttle

(low vacuum).

The MAP sensor is used to determine the following:

DEngine vacuum level for other diagnostics.

DBarometric pressure (BARO).

If the PCM detects a voltage that is lower than the

possible range of the MAP sensor, DTC P0107 will be set.

A signal voltage higher than the possible range of the

sensor will set DTC P0108. The PCM can detect a shifted

MAP sensor . The PCM compares the MAP sensor signal

to a calculated MAP based on throttle position and

various engine load factors.

055RW004

Powertrain Control Module (PCM)

The powertrain control module (PCM) is located in the

passenger compartment below the center console. The

PCM controls the following:

DFuel metering system.

DTransmission shifting (automatic transmission only).

DIgnition timing.

DOn-board diagnostics for powertrain functions.

The PCM constantly observes the information from

various sensors. The PCM controls the systems that

affect vehicle performance. The PCM performs the

diagnostic function of the system. It can recognize

operational problems, alert the driver through the MIL

(Service Engine Soon lamp), and store diagnostic trouble

codes (DTCs). DTCs identify the problem areas to aid the

technician in making repairs.

DIPCM-6KT for automatic transmission-equipped

vehicles.

PCM Function

The PCM supplies either 5 or 12 volts to power various

sensors or switches. The power is supplied through

resistances in the PCM which are so high in value that a

test light will not light when connected to the circuit. In

some cases, even an ordinary shop voltmeter will not give

an accurate reading because its resistance is too low.

Therefore, a digital voltmeter with at least 10 megohms

input impedance is required to ensure accurate voltage

readings. Tool 5–8840–0285–0 meets this requirement.

The PCM controls output circuits such as the injectors,

IAC, cooling fan relays, etc., by controlling the ground or

the power feed circuit through transistors or through

either of the following two devices:

DOutput Driver Module (ODM)

DQuad Driver Module (QDM)

0005

PCM Components

The PCM is designed to maintain exhaust emission levels

to government mandated standards while providing

excellent driveability and fuel efficiency. The PCM

monitors numerous engine and vehicle functions via

electronic sensors such as the throttle position (TP)

sensor, heated oxygen sensor (HO2S), and vehicle

speed sensor (VSS). The PCM also controls certain

engine operations through the following:

DFuel injector control

DIgnition control module

DKnock sensor

DAutomatic transmission shift functions

DEvaporative emission (EVAP) purge

PCM Voltage Description

The PCM supplies a buffered voltage to various switches

and sensors. It can do this because resistance in the

PCM is so high in value that a test light may not illuminate

when connected to the circuit. An ordinary shop

voltmeter may not give an accurate reading because the

voltmeter input impedance is too low . Use a 10-megohm

input impedance digital voltmeter (such as

5–8840–0285–0) to assure accurate voltage readings.

The input/output devices in the PCM include

analog-to-digital converters, signal buffers, counters,

and special drivers. The PCM controls most components

with electronic switches which complete a ground circuit

when turned “ON.” These switches are arranged in

groups of 4 and 7, called either a surface-mounted quad

driver module (QDM), which can independently control up

to 4 output terminals, or QDMs which can independently

control up to 7 outputs. Not all outputs are always used.

PCM Input/Outputs

Inputs – Operating Conditions Read

DAir Conditioning “ON” or “OFF”

DEngine Coolant Temperature

DCrankshaft Position

DExhaust Oxygen Content

DElectronic Ignition

DManifold Absolute Pressure

DBattery Voltage

DThrottle Position

DVehicle Speed

DFuel Pump Voltage

DPower Steering Pressure

DIntake Air Temperature

DMass Air Flow

DEngine Knock

DCamshaft Position

Outputs – Systems Controlled

DEVAP Canister Purge

DExhaust Gas Recirculation (EGR)

DIgnition Control

DFuel Control

DIdle Air Control

DElectric Fuel Pump

DAir Conditioning

DDiagnostics

–Malfunction Indicator Lamp

–Data Link Connector (DLC)

–Data Output

DTransmission Control Module

DAlternator Gain Control

PCM Service Precautions

The PCM is designed to withstand normal current draws

associated with vehicle operation. Avoid overloading any

circuit. When testing for opens and shorts, do not ground

or apply voltage to any of the PCM’s circuits unless

instructed to do so. These circuits should only be tested

using digital voltmeter (5–8840–0285–0). The PCM

should remain connected to the PCM or to a

recommended breakout box.

Throttle Position (TP) Sensor

The throttle position (TP) sensor is a potentiometer

connected to the throttle shaft on the throttle body. The

PCM monitors the voltage on the signal line and

calculates throttle position. As the throttle valve angle is

changed (accelerator pedal moved), the TP sensor signal

also changes. At a closed throttle position, the output of

the TP sensor is low. As the throttle valve opens, the

output increases so that at wide open throttle (WOT), the

output voltage should be above 4 volts.

The PCM calculates fuel delivery based on throttle valve

angle (driver demand). A broken or loose TP sensor may

cause intermittent bursts of fuel from an injector and

unstable idle because the PCM thinks the throttle is

moving. A hard failure in the TP sensor 5-volt reference

or signal circuits will set either a DTC P0122 or DTC

P0123. A hard failure with the TP sensor ground circuit

may set DTC P0123 and DTC P0112. Once a DTC is set,

the PCM will use an artificial default value based on

engine RPM and mass air flow for the throttle position,

and some vehicle performance will return. A high idle

may result when either DTC P0122 or DTC P0123 is set.

The PCM can also detect a shifted TP sensor. The PCM

monitors throttle position and compares the actual TP

sensor reading to a predicted TP value calculated from

engine speed. If the PCM detects an out-of-range

condition, DTC P0121 will be set.

0021

Transmission Fluid Temperature (TFT)

Sensor

The transmission fluid temperature sensor is a thermistor

which changes its resistance based on the temperature of

the transmission fluid. For a complete description of the

TFT sensor, refer to

4L30-E Automatic Transmission

Diagnosis

A failure in the TFT sensor or associated wiring will cause

DTC P0712 or DTC P0713 to set. In this case, engine

coolant temperature will be substituted for the TFT

sensor value and the transmission will operate normally.

Transmission Range Switch

IMPORTANT:The vehicle should not be driven with the

transmission range switch disconnected; idle quality will

be affected.

The four inputs from the transmission range switch

indicate to the PCM which position is selected by the

transmission selector lever. This information is used for

ignition timing, EVAP canister purge, EGR and IAC valve

operation.

For more information on the transmission on the

transmission range switch, refer to

4L30-E Automatic

Transmission

Vehicle Speed Sensor (VSS)The PCM determines the speed of the vehicle by

converting a plusing voltage signal from the vehicle speed

sensor (VSS) into miles per hour. The PCM uses this

signal to operate the cruise control, speedometer, and the

TCC and shift solenoids in the transmission. For more

information on the TCC and shift solenoids, refer to

4L30-E Automatic Transmission.

0008

Use of Circuit Testing Tools

Do not use a test light to diagnose the powertrain

electrical systems unless specifically instructed by the

diagnostic procedures. Use Connector Test Adapter Kit J

35616 whenever diagnostic procedures call for probing

connectors.

Aftermarket Electrical and Vacuum

Equipment

Aftermarket (add-on) electrical and vacuum equipment is

defined as any equipment which connects to the vehicle’s

electrical or vacuum systems that is installed on a vehicle

after it leaves the factory. No allowances have been

made in the vehicle design for this type of equipment.

NOTE:No add-on vacuum equipment should be added

to this vehicle.

NOTE:Add-on electrical equipment must only be

connected to the vehicle’s electrical system at the battery

(power and ground).

Add-on electrical equipment, even when installed to

these guidelines, may still cause the powertrain system to

malfunction. This may also include equipment not

connected to the vehicle electrical system such as

portable telephones and radios. Therefore, the first step

in diagnosing any powertrain problem is to eliminate all

aftermarket electrical equipment from the vehicle. After

this is done, if the problem still exists, it may be diagnosed

in the normal manner.

Electrostatic Discharge Damage

Electronic components used in the PCM are often

designed to carry very low voltage. Electronic

components are susceptible to damage caused by

electrostatic discharge. Less than 100 volts of static

electricity can cause damage to some electronic

components. By comparison, it takes as much as 4000

volts for a person to feel even the zap of a static

discharge.

TS23793

There are several ways for a person to become statically

charged. The most common methods of charging are by

friction and induction.

DAn example of charging by friction is a person sliding

across a vehicle seat.

DCharge by induction occurs when a person with well

insulated shoes stands near a highly charged object

and momentary touches ground. Charges of the

same polarity are drained off leaving the person

highly charged with the opposite polarity. Static

charges can cause damage, therefore it is important

to use care when handling and testing electronic

components.

NOTE:To prevent possible electrostatic discharge

damage, follow these guidelines:

DDo not touch the PCM connector pins or soldered

components on the PCM circuit board.

DDo not touch the knock sensor module component

leads.

DDo not open the replacement part package until the

part is ready to be installed.

DBefore removing the part from the package, ground

the package to a known good ground on the vehicle.

DIf the part has been handled while sliding across the

seat, while sitting down from a standing position, or

while walking a distance, touch a known good ground

before installing the part.

Upshift Lamp

Refer to

Manual Transmission

General Description (Air Induction)

Air Induction System

The air induction system filters contaminants from the

outside air, and directs the progress of the air as it is

drawn into the engine. A remote-mounted air cleaner

prevents dirt and debris in the air from entering the

engine. The air duct assembly routes filtered air to the

throttle body. Air enters the engine by to following steps:

1.Through the throttle body.

2.Into the common chamber.

3.Through the cylinder head intake ports.

4.Into the cylinders.

055RV010

General Description (Fuel Metering)

Acceleration Mode

The PCM provides extra fuel when it detects a rapid

increase in the throttle position and the air flow.

Accelerator Controls

The accelerator control system is a cable-type system

with specific linkage adjustments.

Refer to

Cable Adjustment

. - Section 6E1

Battery Voltage Correction Mode

When battery voltage is low, the PCM will compensate for

the weak spark by increasing the following:

DThe amount of fuel delivered.

DThe idle RPM.

DIgnition dwell time.

CMP Signal

The PCM uses this signal to determine the position of the

number 1 piston during its power stroke, allowing the

PCM to calculate true sequential multiport fuel injection

(SFI). Loss of this signal will set a DTC P0341. If the CMP

signal is lost while the engine is running, the fuel injection

system will shift to a calculated sequential fuel injection

based on the last fuel injection pulse, and the engine will

continue to run. The engine can be restarted and will run

in the calculated sequential mode as long as the fault is

present, with a 1-in-6 chance of being correct.

Clear Flood Mode

Clear a flooded engine by pushing the accelerator pedal

down all the way. The PCM then de-energizes the fuel

injectors. The PCM holds the fuel injectors de-energized

as long as the throttle remains above 80% and the engine

speed is below 800 RPM. If the throttle position becomes

less than 80%, the PCM again begins to pulse the

injectors “ON” and “OFF,” allowing fuel into the cylinders.

Deceleration Mode

The PCM reduces the amount of fuel injected when it

detects a decrease in the throttle position and the air flow.

When deceleration is very fast, the PCM may cut off fuel

completely for short periods.

Engine Speed/Vehicle Speed/Fuel Disable

Mode

The PCM monitors engine speed. It turns off the fuel

injectors when the engine speed increase above 6400

RPM. The fuel injectors are turned back on when engine

speed decreases below 6150 RPM.

Fuel Cutoff Mode

No fuel is delivered by the fuel injectors when the ignition

is “OFF.” This prevents engine run-on. In addition, the

PCM suspends fuel delivery if no reference pulses are

detected (engine not running) to prevent engine flooding.

Fuel Injector

The sequential multiport fuel injection (SFI) fuel injector is

a solenoid-operated device controlled by the PCM. The

PCM energizes the solenoid, which opens a valve to allow

fuel delivery.

The fuel is injected under pressure in a conical spray

pattern at the opening of the intake valve. Excess fuel not

used by the injectors passes through the fuel pressure

regulator before being returned to the fuel tank.

A fuel injector which is stuck partly open will cause a loss

of fuel pressure after engine shut down, causing long

crank times.

0003

Fuel Metering System Components

The fuel metering system is made up of the following

parts:

DThe fuel injectors.

DThe throttle body.

DThe fuel rail.

DThe fuel pressure regulator.

DThe PCM.

DThe crankshaft position (CKP) sensor.

DThe camshaft position (CMP) sensor.

DThe idle air control (IAC) valve.

DThe fuel pump.

DThe fuel pump relay.

Basic System Operation

The fuel metering system starts with the fuel in the fuel

tank. An electric fuel pump, located in the fuel tank,

pumps fuel to the fuel rail through an in-line fuel filter. The

pump is designed to provide fuel at a pressure above the

pressure needed by the injectors. A fuel pressure

regulator in the fuel rail keeps fuel available to the fuel

injectors at a constant pressure. A return line delivers

unused fuel back to the fuel tank. Refer to

Section 6C

for

further information on the fuel tank, line filter, and fuel

pipes.

Fuel Metering System Purpose

The basic function of the air/fuel metering system is to

control the air/fuel delivery to the engine. Fuel is delivered

to the engine by individual fuel injectors mounted in the

intake manifold near each intake valve.

The main control sensor is the heated oxygen sensor

(HO2S) located in the exhaust system. The HO2S tells

the PCM how much oxygen is in the exhaust gas. The

PCM changes the air/fuel ratio to the engine by controlling

the amount of time that fuel injector is “ON.” The best

mixture to minimize exhaust emissions is 14.7 parts of air

to 1 part of gasoline by weight, which allows the catalytic

converter to operate most efficiently. Because of the

constant measuring and adjusting of the air/fuel ratio, the

fuel injection system is called a “closed loop” system.

The PCM monitors signals from several sensors in order

to determine the fuel needs of the engine. Fuel is

delivered under one of several conditions called “modes.”

All modes are controlled by the PCM.

Fuel Pressure Regulator

The fuel pressure regulator is a diaphragm-operated

relief valve mounted on the fuel rail with fuel pump

pressure on one side and manifold pressure on the other

side. The fuel pressure regulator maintains the fuel

pressure available to the injector at three times

barometric pressure adjusted for engine load. It may be

serviced separate.

If the pressure is too low, poor performance and a DTC

P0131, DTC P0151,DTC P0171 will be the result. If the

pressure is too high, excessive odor and/or a DTC P0132,

DTC P0152,DTC P0172 or DTC P0175 will be the result.

Refer to

Fuel System Diagnosis

for information on

diagnosing fuel pressure conditions.

0011

Fuel Pump Electrical Circuit

When the key is first turned “ON,” the PCM energizes the

fuel pump relay for two seconds to build up the fuel

pressure quickly. If the engine is not started within two

seconds, the PCM shuts the fuel pump off and waits until

the engine is cranked. When the engine is cranked and

the 58 X crankshaft position signal has been detected by

the PCM, the PCM supplies 12 volts to the fuel pump relay

to energize the electric in-tank fuel pump.

An inoperative fuel pump will cause a “no-start” condition.

A fuel pump which does not provide enough pressure will

result in poor performance.

Fuel Rail

The fuel rail is mounted to the top of the engine and

distributes fuel to the individual injectors. Fuel is

delivered to the fuel inlet tube of the fuel rail by the fuel

lines. The fuel goes through the fuel rail to the fuel

pressure regulator. The fuel pressure regulator maintains

a constant fuel pressure at the injectors. Remaining fuel

is then returned to the fuel tank.

055RV009

Idle Air Control (IAC) Valve

The purpose of the idle air control (IAC) valve is to control

engine idle speed, while preventing stalls due to changes

in engine load. The IAC valve, mounted in the throttle

body, controls bypass air around the throttle plate. By

moving the conical valve (pintle) in (to decrease air flow)

or out (to increase air flow), a controlled amount of air can

move around the throttle plate. If the RPM is too low , the

PCM will retract the IAC pintle, resulting in more air

moving past the throttle plate to increase the RPM. If the

RPM is too high, the PCM will extend the IAC pintle,

allowing less air to move past the throttle plate,

decreasing the RPM.

The IAC pintle valve moves in small steps called counts.

During idle, the proper position of the IAC pintle is

calculated by the PCM based on battery voltage, coolant

temperature, engine load, and engine RPM. If the RPM

drops below a specified value, and the throttle plate is

closed, the PCM senses a near-stall condition. The PCM

will then calculate a new IAC pintle valve position to

prevent stalls.

If the IAC valve is disconnected and reconnected with the

engine running, the idle RPM will be wrong. In this case,

the IAC must be reset. The IAC resets when the key is

cycled “ON” then “OFF.” When servicing the IAC, it

should only be disconnected or connected with the

ignition “OFF.”

The position of the IAC pintle valve affects engine start-up

and the idle characteristics of the vehicle. If the IAC pintle

is fully open, too much air will be allowed into the manifold.

This results in high idle speed, along with possible hard

starting and a lean air/fuel ratio.

0006

Run Mode

The run mode has the following two conditions:

DOpen loop

DClosed loop

When the engine is first started the system is in “open

loop” operation. In “open loop,” the PCM ignores the

signal from the heated oxygen sensor (HO2S). It

calculates the air/fuel ratio based on inputs from the TP,

ECT, and MAF sensors.

The system remains in “open loop” until the following

conditions are met:

DThe HO2S has a varying voltage output showing that

it is hot enough to operate properly (this depends on

temperature).

DThe ECT has reached a specified temperature.

DA specific amount of time has elapsed since starting

the engine.

DEngine speed has been greater than a specified RPM

since start-up.

The specific values for the above conditions vary with

different engines and are stored in the programmable

read only memory (PROM). When these conditions are

met, the system enters “closed loop” operation. In

“closed loop,” the PCM calculates the air/fuel ratio

(injector on-time) based on the signal from the HO2S.

This allows the air/fuel ratio to stay very close to 14.7:1.

Starting Mode

When the ignition is first turned “ON,” the PCM energizes

the fuel pump relay for two seconds to allow the fuel pump

to build up pressure. The PCM then checks the engine

coolant temperature (ECT) sensor and the throttle

position (TP) sensor to determine the proper air/fuel ratio

for starting.

The PCM controls the amount of fuel delivered in the

starting mode by adjusting how long the fuel injectors are

energized by pulsing the injectors for very short times.

Throttle Body Unit

The throttle body has a throttle plate to control the amount

of air delivered to the engine. The TP sensor and IAC

valve are also mounted on the throttle body. Vacuum

ports located behind the throttle plate provide the vacuum

signals needed by various components.

Engine coolant is directed through a coolant cavity in the

throttle body to warm the throttle valve and to prevent

icing.

0019

General Description (Electronic

Ignition System)

Camshaft Position (CMP) Sensor

The camshaft position (CMP) sensor is located on the

rear left side. As the camshaft sprocket turns, a magnet in

the sprocket activates the Hall-effect switch in the CMP

sensor. When the Hall-effect switch is activated, it

grounds the signal line to the PCM, pulling the camshaft

position sensor signal circuit’s applied voltage low. This is

a CMP signal. The CMP signals is created as piston #1 is

approximately 25° after top dead counter on the power

stroke. If the correct CMP signal is not received by the

PCM, DTC P0341 will be set.

0014

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor provides a signal

used by the powertrain control module (PCM) to calculate

the ignition sequence. The sensor initiates the 58X

reference pulses which the PCM uses to calculate RPM

and crankshaft position. Refer to

Electronic Ignition

System

for additional information.

Electronic IgnitionThe electronic ignition system controls fuel combustionby providing a spark to ignite the compressed air/fuel

mixture at the correct time. To provide optimum engine

performance, fuel economy, and control of exhaust

emissions, the PCM controls the spark advance of the

ignition system. Electronic ignition has the following

advantages over a mechanical distributor system:

DNo moving parts.

DLess maintenance.

DRemote mounting capability.

DNo mechanical load on the engine.

DMore coil cooldown time between firing events.

DElimination of mechanical timing adjustments.

DIncreased available ignition coil saturation time.

0013

Ignition CoilsA separate coil-at-plug module is located at each spark

plug. The coil-at-plug module is attached to the engine

with two screws. It is installed directly to the spark plug by

an electrical contact inside a rubber boot. A three-way

connector provides 12-volt primary supply from the

15-amp ignition fuse, a ground-switching trigger line from

the PCM, and a ground.

0001

Ignition ControlThe ignition control (IC) spark timing is the PCM’s method

of controlling the spark advance and the ignition dwell.

The IC spark advance and the ignition dwell are

calculated by the PCM using the following inputs:

DEngine speed.

DCrankshaft position (58X reference).

DCamshaft position (CMP) sensor.

DEngine coolant temperature (ECT) sensor.

DThrottle position (TP) sensor.

DKnock signal (knock sensor).

DPark/Neutral position (PRNDL input).

DVehicle speed (vehicle speed sensor).

DPCM and ignition system supply voltage.

DThe crankshaft positron (CKP) sensor sends the

PCM a 58X signal related to the exact position of the

crankshaft.

TS22909

DThe camshaft position (CMP) sensor sends a signal

related to the position of the camshaft.

DThe knock sensor tells the PCM if there is any

problem with pre-ignition or detonation. This

information allows the PCM to retard timing, if

necessary.

TS24037

Based on these sensor signals and engine load

information, the PCM sends 5V to each ignition coil.

060RW015

The PCM applies 5V signal voltage to the ignition coil

requiring ignition. This signal sets on the power transistor

of the ignition coil to establish a grounding circuit for the

primary coil, applying battery voltage to the primary coil.

At the ignition timing, the PCM stops sending the 5V

signal voltage. Under this condition the power transistor

of the ignition coil is set off to cut the battery voltage to the

primary coil, thereby causing a magnetic field generated

in the primary coil to collapse. On this moment a line of

magnetic force flows to the secondary coil, and when this

magnetic line crosses the coil, high voltage induced by

the secondary ignition circuit to flow through the spark

plug to the ground.

TS24047

Ignition Control PCM Output

The PCM provides a zero volt (actually about 100 mV to

200 mV) or a 5-volt output signal to the ignition control (IC)

module. Each spark plug has its own primary and

secondary coil module (”coil-at-plug”) located at the spark

plug itself. When the ignition coil receives the 5-volt signal

from the PCM, it provides a ground path for the B+ supply

to the primary side of the coil-at -plug module. This

energizes the primary coil and creates a magnetic field in

the coil-at-plug module. When the PCM shuts off the

5-volt signal to the ignition control module, the ground

path for the primary coil is broken. The magnetic field

collapses and induces a high voltage secondary impulse

which fires the spark plug and ignites the air/fuel mixture.

The circuit between the PCM and the ignition coil is

monitored for open circuits, shorts to voltage, and shorts

to ground. If the PCM detects one of these events, it will

set one of the following DTCs:

DP0351: Ignition coil Fault on Cylinder #1

DP0352: Ignition coil Fault on Cylinder #2

DP0353: Ignition coil Fault on Cylinder #3

DP0354: Ignition coil Fault on Cylinder #4

DP0355: Ignition coil Fault on Cylinder #5

DP0356: Ignition coil Fault on Cylinder #6

Knock Sensor (KS) PCM Input

The knock sensor (KS) system is comprised of a knock

sensor and the PCM. The PCM monitors the KS signals

to determine when engine detonation occurs. When a

knock sensor detects detonation, the PCM retards the

spark timing to reduce detonation. Timing may also be

retarded because of excessive mechanical engine or

transmission noise.

Powertrain Control Module (PCM)

The PCM is responsible for maintaining proper spark and

fuel injection timing for all driving conditions. To provide

optimum driveability and emissions, the PCM monitors

the input signals from the following components in order

to calculate spark timing:

DEngine coolant temperature (ECT) sensor.

DIntake air temperature (IAT) sensor.

DMass air flow (MAF) sensor.

DPRNDL input from transmission range switch.

DThrottle position (TP) sensor.

DVehicle speed sensor (VSS) .

DCrankshaft position (CKP) sensor.

Spark Plug

Although worn or dirty spark plugs may give satisfactory

operation at idling speed, they frequency fail at higher

engine speeds. Faulty spark plugs may cause poor fuel

economy, power loss, loss of speed, hard starting and

generally poor engine performance. Follow the

scheduled maintenance service recommendations to

ensure satisfactory spark plug performance. Refer to

Maintenance and Lubrication

Normal spark plug operation will result in brown to

grayish-tan deposits appearing on the insulator portion of

the spark plug. A small amount of red-brown, yellow, and

white powdery material may also be present on the

insulator tip around the center electrode. These deposits

are normal combustion by-products of fuels and

lubricating oils with additives. Some electrode wear will

also occur.

Carbon fouling of the spark plug is indicated by dry, black

carbon (soot) deposits on the portion of the spark plug in

the cylinder. Excessive idling and slow speeds under

light engine loads can keep the spark plug temperatures

so low that these deposits are not burned off. Very rich

fuel mixtures or poor ignition system output may also be

the cause. Refer to DTC P0172.

Oil fouling of the spark plug is indicated by wet oily

deposits on the portion of the spark plug in the cylinder,

usually with little electrode wear . This may be caused by

oil during break-in of new or newly overhauled engines.

Deposit fouling of the spark plug occurs when the normal

red-brown, yellow or white deposits of combustion by

products become sufficient to cause misfiring. In some

cases, these deposits may melt and form a shiny glaze on

the insulator around the center electrode. If the fouling is

found in only one or two cylinders, valve stem clearances

or intake valve seals may be allowing excess lubricating

oil to enter the cylinder, particularly if the deposits are

heavier on the side of the spark plug facing the intake

valve.

TS23995

Excessive gap means that the air space between the

center and the side electrodes at the bottom of the spark

plug is too wide for consistent firing. This may be due to

improper gap adjustment or to excessive wear of the

electrode during use. A check of the gap size and

comparison to the gap specified for the vehicle in

Maintenance and Lubrication

will tell if the gap is too wide.

A spark plug gap that is too small may cause an unstable

idle condition. Excessive gap wear can be an indication

of continuous operation at high speeds or with engine

loads, causing the spark to run too hot. Another possible

cause is an excessively lean fuel mixture.

TS23992

Low or high spark plug installation torque or improper

seating can result in the spark plug running too hot and

can cause excessive center electrode wear. The plug

and the cylinder head seats must be in good contact for

proper heat transfer and spark plug cooling. Dirty or

damaged threads in the head or on the spark plug can

keep it from seating even though the proper torque is

applied. Once spark plugs are properly seated, tighten

them to the torque shown in the Specifications T able. Low

torque may result in poor contact of the seats due to a

loose spark plug. Overtightening may cause the spark

plug shell to be stretched and will result in poor contact

between the seats. In extreme cases, exhaust blow-by

and damage beyond simple gap wear may occur.

Cracked or broken insulators may be the result of

improper installation, damage during spark plug

re-gapping, or heat shock to the insulator material. Upper

insulators can be broken when a poorly fitting tool is used

during installation or removal, when the spark plug is hit

from the outside, or is dropped on a hard surface. Cracks

in the upper insulator may be inside the shell and not

visible. Also, the breakage may not cause problems until

oil or moisture penetrates the crack later.

TS23994

A broken or cracked lower insulator tip (around the center

electrode) may result from damage during re-gapping or

from “heat shock” (spark plug suddenly operating too

hot).

TS23993

DDamage during re-gapping can happen if the gapping

tool is pushed against the center electrode or the

insulator around it, causing the insulator to crack.

When re-gapping a spark plug, make the adjustment

by bending only the ground side terminal, keeping the

tool clear of other parts.

D”Heat shock” breakage in the lower insulator tip

generally occurs during several engine operating

conditions (high speeds or heavy loading) and may be

caused by over-advanced timing or low grade fuels.

Heat shock refers to a rapid increase in the tip

temperature that causes the insulator material to

crack.

Spark plugs with less than the recommended amount of

service can sometimes be cleaned and re-gapped , then

returned to service. However , if there is any doubt about

the serviceability of a spark plug, replace it. Spark plugs

with cracked or broken insulators should always be

replaced.

A/C Clutch Diagnosis

A/C Clutch Circuit Operation

A 12-volt signal is supplied to the A/C request input of the

PCM when the A/C is selected through the A/C control

switch.

The A/C compressor clutch relay is controlled through the

PCM. This allows the PCM to modify the idle air control

position prior to the A/C clutch engagement for better idle

quality. If the engine operating conditions are within their

specified calibrated acceptable ranges, the PCM will

enable the A/C compressor relay. This is done by

providing a ground path for the A/C relay coil within the

PCM. When the A/C compressor relay is enabled,

battery voltage is supplied to the compressor clutch coil.

The PCM will enable the A/C compressor clutch

whenever the engine is running and the A/C has been

requested. The PCM will not enable the A/C compressor

clutch if any of the following conditions are met:

DThe throttle is greater than 90%.

DThe engine speed is greater than 6315 RPM.

DThe ECT is greater than 119°C (246°F).

DThe IAT is less than 5°C (41°F).

DThe throttle is more than 80% open.

A/C Clutch Circuit Purpose

The A/C compressor operation is controlled by the

powertrain control module (PCM) for the following

reasons:

DIt improvises idle quality during compressor clutch

engagement.

DIt improvises wide open throttle (WOT) performance.

DIt provides A/C compressor protection from operation

with incorrect refrigerant pressures.

The A/C electrical system consists of the following

components:

DThe A/C control head.

DThe A/C refrigerant pressure switches.

DThe A/C compressor clutch.

DThe A/C compressor clutch relay.

DThe PCM.

A/C Request Signal

This signal tells the PCM when the A/C mode is selected

at the A/C control head. The PCM uses this to adjust the

idle speed before turning on the A/C clutch. The A/C

compressor will be inoperative if this signal is not

available to the PCM.

Refer to

A/C Clutch Circuit Diagnosis

for A/C wiring

diagrams and diagnosis for A/C electrical system.

General Description (Evaporative

(EVAP) Emission System)

EVAP Emission Control System Purpose

The basic evaporative emission (EVAP) control system

used on all vehicles is the charcoal canister storage

method. Gasoline vapors from the fuel tank flow into the

canister through the inlet labeled “TANK.” These vapors

are absorbed into the activated carbon (charcoal) storage

device (canister) in order to hold the vapors when the

vehicle is not operating. The canister is purged by PCM

control when the engine coolant temperature is over 60°C

(140°F), the IAT reading is over 10°C (50°F), and the

engine has been running. Air is drawn into the canister

through the air inlet grid. The air mixes with the vapor and

the mixture is drawn into the intake manifold.

EVAP Emission Control System Operation

The EVAP canister purge is controlled by a solenoid valve

that allows the manifold vacuum to purge the canister.

The powertrain control module (PCM) supplies a ground

to energize the solenoid valve (purge on). The EVAP

purge solenoid control is pulse-width modulated (PWM)

(turned on and off several times a second). The duty

cycle (pulse width) is determined by engine operating

conditions including load, throttle positron, coolant

temperature and ambient temperature. The duty cycle is

calculated by the PCM. The output is commanded when

the appropriate conditions have been met. These

conditions are:

DThe engine is fully warmed up.

DThe engine has been running for a specified time.

DThe IAT reading is above 10°C (50°F).

Poor idle, stalling and poor driveability can be caused by:

DA malfunctioning purge solenoid.

DA damaged canister.

DHoses that are split, cracked, or not connected

properly.

General Description (Exhaust Gas

Recirculation (EGR) System)

EGR Purpose

The exhaust gas recirculation (EGR) system is use to

reduce emission levels of oxides of nitrogen (NOx). NOx

emission levels are caused by a high combustion

temperature. The EGR system lowers the NOx emission

levels by decreasing the combustion temperature.

057RW002

Linear EGR Valve

The main element of the system is the linear EGR valve.

The EGR valve feeds small amounts of exhaust gas back

into the combustion chamber . The fuel/air mixture will be

diluted and combustion temperatures reduced.

Linear EGR Control

The PCM monitors the EGR actual positron and adjusts

the pintle position accordingly. The uses information from

the following sensors to control the pintle position:

DEngine coolant temperature (ECT) sensor.

DThrottle position (TP) sensor.

DMass air flow (MAF) sensor.

Linear EGR Valve Operation and Results

of Incorrect Operation

The linear EGR valve is designed to accurately supply

EGR to the engine independent of intake manifold

vacuum. The valve controls EGR flow from the exhaust

to the intake manifold through an orifice with a PCM

controlled pintle. During operation, the PCM controls

pintle position by monitoring the pintle position feedback

signal. The feedback signal can be monitored with a T ech

2 as “Actual EGR Pos.” “Actual EGR Pos.” should always

be near the commanded EGR position (”Desired EGR

Pos.”). If a problem with the EGR system will not allow the

PCM to control the pintle position properly, DTC P1404

will set. The PCM also tests for EGR flow.

The linear EGR valve is usually activated under the

following conditions:

DWarm engine operation.

DAbove-idle speed.

Too much EGR flow at idle, cruise or cold operation may

cause any of the following conditions to occur:

DEngine stalls after a cold start.

DEngine stalls at idle after deceleration.

DVehicle surges during cruise.

DRough idle.

Too little or no EGR flow may allow combustion

temperatures to get too high. This could cause:

DSpark knock (detonation).

DEngine overheating.

DEmission test failure.

DPoor fuel economy.

0017

EGR Pintle Position Sensor

The PCM monitors the EGR valve pintle position input to

endure that the valve responds properly to commands

from the PCM and to detect a fault if the pintle position

sensor and control circuits are open or shorted. If the

PCM detects a pintle position signal voltage outside the

normal range of the pintle position sensor, or a signal

voltage that is not within a tolerance considered

acceptable for proper EGR system operation, the PCM

will set DTC P1404.

General Description (Positive

Crankcase Ventilation (PCV) System)

Crankcase Ventilation System Purpose

The crankcase ventilation system is use to consume

crankcase vapors in the combustion process instead of

venting them to the atmosphere. Fresh air from the

throttle body is supplied to the crankcase and mixed with

blow-by gases. This mixture is then passed through the

positive crankcase ventilation (PCV) valve into the

common chamber.

Crankcase Ventilation System Operation

The primary control is through the positive crankcase

ventilation (PCV) valve. The PCV valve meters the flow at

a rate that depends on the intake vacuum. The PCV valve

restricts the flow when the inlet vacuum is highest. In

addition, the PCV valve can seal the common chamber

off in case of sudden high pressure in the crankcase.

028RV002

While the engine is running, exhaust fuses and small

amounts of the fuel/air mixture escape past the piston

rings and enter the crankcase. These gases are mixed

with clean air entering through a tube from the air intake

duct.

028RW002

During normal, part-throttle operation, the system is

designed to allow crankcase gases to flow through the

PCV valve into the throttle body to be consumed by

normal combustion.

A plugged valve or PCV hose may cause the following

conditions:

DRough idle.

DStalling of slow idle speed.

DOil leaks.

DSludge in the engine.

A leaking PCV hose would cause:

DRough idle.

DStalling.

DHigh idle speed.

Special Tools

ILLUSTRATION TOOL NO.

TOOL NAME

5-8840-0285-0

High Impedance

Multimeter (Digital

Voltmeter – DVM)

(1) PCMCIA Card

(2) RS232 Loop Back

Connector

(3) SAE 16/19 Adapter

(4) DLC Cable

(5) TECH–2

5-8840-0607-0

Unpowered Test Light

5-8840-0385-0

Connector Test Adapter

5-8840-0383-0

Spark Tester

5-8840-0279-0

Vacuum Pump with

Gauge

ILLUSTRATION TOOL NO.

TOOL NAME

5-8840-2640-0

Heated Oxygen Sensor

Wrench

5-8840-0632-0

Terminal Remover

5-8840-0388-0

Weather Pack II

Terminal Remover

5-8840-2636-0

Injector Test Light

5-8840-2607-0

EVAP Pressure/Purge

Diagnostic Station