SECTION 2F - ELECTRONIC CLIMATE CONTROL -

DIAGNOSTICS

CAUTION:

This vehicle will be equipped with a Supplemental Restraint System (SRS). A SRS will

consist of either seat belt pre-tensio ners and a driver’s side air bag, o r seat belt pre-

tensioners and a driver’s and front passenger’s side air bags. Refer to CAUTIONS,

Section 12M, before performing any service operation on or around SRS

components, the steering mechanism or wiring. Failure to follow the CAUTIONS

could result in SRS deployment, resu lting in possible perso nal in jury or u nnecessary

SRS system repairs.

CAUTION:

This vehicle may be equipped with LPG (Liquefied Petroleum Gas). In the interests of

safety, the LPG fuel system should be isolated by turning 'OFF' the manual service

valve and then draining the L PG service lines, before any service w ork is carried out

on the vehicle. Refer to the LPG leaflet included with the Owner's Handbook for

details or LPG Section 2 for more specific servicing information.

1. DIAGNOSTICS

1.1 TECH 2 DIAGNOSTICS

TECH 2, with the appropriate software, cables and

adaptors, when connected to the Data Link

Connector (DLC) is capable of reading ECC serial

data. The DLC is connected to the instrument panel

lower right hand trim, to the right of the steering

column.

For additional general information on connecting

and operating TECH 2 , refer to

Section 0C TECH 2.

Figure 2F-1

Techline

TECH 2 has six tes t modes f or diagnos ing the ECC

The six test modes are as follows:

Mode F0: Normal Mode

In this mode, the TECH 2 monitors the

communication between control modules on the

serial data line. The information displayed on the

TECH 2 screen in this mode is what the ECC is

communicating to the other modules via the serial

data line.

Mode F1: Diagnostic Trouble Codes (DTC)

In this test mode, the operator of TECH 2 has the

option of reading current and history DTC’s or

clearing stored DTC’s from the control modules

memory.

Mode F2: Data Display

In this test mode, TECH 2 displays the status of

inputs and outputs of the ECC.

Mode F3: Snapshot

In this test mode, the TECH 2 captures ECC data

before and after a forced manual trigger.

Mode F4: Miscellaneous Tests

In this test mode, the TECH 2 performs system

functional tests to assist in pr oblem isolation during

troubleshooting.

Each test mode has specific diagnosis capabilities

that depend upon various function key entry on the

TECH 2.

Mode F5: Program

In this test m ode, TECH 2 allows the programming

of various ECC features (ie. calibration of driver’s

air mix door.

Figure 2F-2

1.2 TECH 2 TEST MODES AND DISPLAYS FOR ECC DIAGNOSIS

A prerequisite to this diagnostic section is for the

user to be familiar with the proper use of TECH 2.

The following pages illustrate only the major TECH

2 screen displays and provide a brief explanation of

their function for diagnosing the ECC. If additional

information is required on the operation of TECH 2,

reference should be made to either

Section 0C TECH 2, or the TECH 2 OPERATOR’S

MANUAL.

System Select Menu

With TECH 2 connected to the DLC, the F0:

Diagnostics selected from the Main Menu, the

correct Model Year and Vehicle Type must be

selected for access to the System Select Menu.

Select F3: Body.

This mode contains all functions to test, diagnose,

monitor and program the vehicles body systems

including the ECC as well as providing the

opportunity to check all DTC’s that may be set in

the vehicle.

Figure 2F-3

Body Applica tion Menu

Once F3: Body has been selected f rom the System

Select Menu, ECC can be selected.

Select ECC.

NOTE: If information regarding DTC’s set for the

vehicle is required, select DTC Check and press

enter to continue. To return to the ECC mode

option from the DTC Check mode option screen

display, simply press the EXIT key on TECH 2.

Once the ECC has been s elec ted, the f ollowing two

System Identification screens will appear which

require action.

Figure 2F-4

System Identification

Turn the ignition ON (as requested) and press

CONFIRM soft key to continue.

Figure 2F-5

Techline

The System Identification screen will then display

ECC control module identification data. Press the

CONFIRM soft key to continue to the ECC

Application Menu.

Figure 2F-6

Application Menu

The following functions will now be available:

F0: Normal Mode

F1: Diagnostic Trouble Codes

F2: Data Display

F3: Snapshot

F4: Miscellaneous Tests

F5: Program

Figure 2F-7

F0: NORMAL MODE

In the F0: Normal Mode, information that the ECC

control module is communicating to other control

modules, via the serial data line, is displayed.

For example: As displayed opposite, the A/C

request status is YES. This m eans the ECC control

module is com m unic ating with the BCM, requesting

the air conditioning compressor to be turned on.

Figure 2F-8

F1: DIAGNOSTIC TROUBLE CODES (DTC)

If F1: Diagnostic Trouble Codes is selected, a

selection list is displayed which contains:

F0: Read Current DTC Information: In this m ode,

a listing of all (if any) current DTC numbers,

together with a brief description of the DT C, will be

displayed.

F1: Read History DTC Information: In this mode,

a listing of the last two stored DTC’s will be

displayed, together with a brief description of the

DTC and the number of ignition cycles since the

DTC occurred.

NOTE: If any DTC’s are set, reference should be

made to the relevant diagnostic charts in this

Section.

F2: Clear DTC Information: In this mode, DTC’s

can be cleared by simply selecting F2: Clear DTC

Information and pressing the enter key on TECH 2.

The following table sets out all the possible

diagnostic trouble codes as indicated by TECH 2.

Figure 2F-9

DTC CODE DESCRIPTION

13 Ambient temperature sensor out of range - high

14 Ambient temperature sensor out of range - low

15 In car temperature sensor out of range - high

16 In car temperature sensor out of range - low

17 Evaporator air temperature sensor out of range - high

18 Evaporator air temperature sensor out of range - low

19 Sun load sensor fault

21 Air mix motor drivers side - dual & single zone

(motor & PBR test)

24 Air mix motor passenger’s side - dual zone only

(motor & PBR test)

36 Serial data communication error

37 ECC control module - Internal failure

38 EEPROM failure (ECC control module)

NOTE:

For diagnosis of pressure transducers, refer to

Section 6C1 POWERTRAIN CONTROL M ODULE

- V6 ENGINE or 6C2 POWERTRAIN CONTROL

MODULE - V8 ENGINE.

F2: DATA DISPLAY

If the F2: Data Display mode is selected, an

additional menu will appear giving the operator the

option of selec ting the ECC data list or ECC switch

data.

F0: Data list - The data list displays inputs and

outputs of the ECC.

F1: Switch Data - In this mode, the operator is

able to test the function of each ECC module

button and switch.

To test the ECC buttons and switches in this m ode;

activate each button and switch on the ECC

module and view the TECH 2 screen to see if

display changes status from OFF to ON.

NOTE:

The ECC module buttons will need to be held down

when carrying out this test due to a slight delay in

information transfer.

The following table lists each item in the data list

and the switch data together with expected

readings:

Figure 2F-10

DATA LIST READING SWITCH DATA READING

System status On/Off Right Set Temperature Up On/Off

In car Temperature Sensor 0 - 3.5 ± 0.2 V Right Set Temperature

Down On/Off

In car Temperature Degrees °CRear Demist Switch On/Off

Ambient Temperature

Sensor 0 - 3.5 ± 0.2 V Front Demist Switch On/Off

Ambient Temperature Degrees °CRecirculation Switch On/Off

Evap Temperature Sensor 0 - 3.5 ± 0.2 V Fan Up Switch On/Off

Evap Temperature Degrees °CFan Down Switch On/Off

Coolant Temperature Degrees °CAir Conditioning Switch On/Off

Battery Voltage Approx 13.5 V Mode Switch On/Off

Drivers Air Mix Door 0 - 3.5 ± 0.2 V Outside Temperature

Switch On/Off

Passengers Air Mix Door 0 - 3.5 ± 0.2 V Left Side Temperature

Switch On/Off

Outlet Setting Auto/Manual (Dual Zone Only)

Outlet Mode Face/Floor/

Blend/Foot Left Side Temperature Up On/Off

Inlet Setting Auto/Manual (Dual Zone Only)

Inlet Mode Fresh/Recirc Auto Switch On/Off

Air Conditioning Setting Auto/Manual Off Switch On/Off

Air Conditioning Request Yes/No

Blower Fan Setting Auto/Manual

Blower Fan Speed 1234/Auto

Cold Start 22 - 99%

Maximum Fan Relay Yes/No

Rear Demist Relay On/Off

Face 1 Solenoid On/Off

Face 2 Solenoid On/Off

Foot 1 Solenoid On/Off

Foot 2 Solenoid On/Off

Recirculation Solenoid On/Off

Water Valve On/Off

F3: SNAPSHOT

In this test mode, the TECH 2 captures ECC data

before and after a forced manual trigger.

F4: MISCELLANEOUS TEST

In the Miscellaneous Test mode, functional tests

are available on the ECC systems that will help

identify proper operation. In this mode, error

conditions can be further identified by testing and

observing the results.

In the Miscellaneous T est m ode, the f ollowing tests

can be performed:

Drivers Side Air Mix Door

Purpose of test: Monitor the face vent to verify that

a temperature change takes place when opening

and closing the air m ix door, indicating both air m ix

motor and door movement.

Pre-conditions: Engine running at operating

temperature.

Procedure: Insert a thermometer into the centre

face vent (dual zone, right side centre vent). With

TECH 2 connec ted to DLC, s elect Body / Elec tronic

Climate Control / Drivers Side Air Mix Door.

Conduct Drivers Side Air Mix Door test by using the

increase/decrease soft keys on TECH 2 open and

close the air mix door.

W hen the door is open (increase), the temperature

at the centre vent should increase.

When the door is closed (decrease), the

temperature at the centre vent should decrease.

Figure 2F-11

Passenger Side Air Mix Door

Purpose of test: Monitor the face vent to verify that

a temperature change takes place when opening

and closing the air m ix door, indicating both air m ix

motor and door movement.

Pre-conditions: Engine running at operating

temperature.

Procedure: Insert a thermometer into the left side

of the centre face vent. W ith TECH 2 connected to

DLC, select Body / Electronic Climate Control /

Passengers Side Air Mix Door. Conduct Pass enger

Side Air Mix Door test by using the

increase/decrease soft keys on TECH 2 open and

close the air mix door.

W hen the door is open (increase), the temperature

at the centre vent should increase.

When the door is closed (decrease), the

temperature at the centre vent should decrease.

Figure 2F-12

Blower Speed

Purpose of test: To ensure that all blower speeds

are preset and the blower motor circuit is

functional.

Pre-condition: Engine running

Procedure: With T ECH 2 connected to DLC, s elect

Body / Electronic Climate Control / Miscellaneous

Tests / Blower Speed. Using the increase soft key

on TECH 2, command the blower fan to maximum

(approx. 95 - 99%).

Using the decreas e soft k ey on TECH 2, com m and

the blower fan to minimum (approximately 22 -

26%).

NOTE:

Percentage values (%) are dependant on vehicle

battery voltage.

Figure 2F-13

LCD Display Test

Purpose of test: To ensure all segments are

displayed on the ECC module LCD screen.

Pre-condition: Engine not running.

Procedure: With T ECH 2 connected to DLC, s elect

Body / Electronic Climate Control / Miscellaneous

Tests / LCD Display Test. Using the On/Off soft

keys on TECH 2, activate and deactivate the LCD

full segment display.

Figure 2F-14

Outlet Mode

Purpose of test: To ensure that vacuum solenoids,

vacuum supply and mode doors are functional.

Pre-condition - Engine running.

Procedure: With T ECH 2 connected to DLC, s elect

Body / Electronic Climate Control / Miscellaneous

Tests / Outlet Mode. Conduct Outlet Mode test by

using the up/down soft keys on TECH 2 and

scrolling through each mode position; Foot,

Foot/Face, Face, Demist/Foot and Demist (only).

The ECC Module LCD indicates the position

(arrow) air will be directed to, in each mode the

third blower fan speed will automatically be

selected and the Auto button will be illuminated.

Feel for air movement at the direction indicated by

the arrow on the ECC Module LCD screen.

NOTE 1:

When the Foot Mode is selected, air is distributed

from the floor.

NOTE 2:

On dual zone systems, when the Face Vent Mode

is selected, air will be distributed from left and right

or the centre face vent.

NOTE 3:

When the Demist/Foot Mode is selected, air is

distributed from demist ducts and the floor.

NOTE 4:

When the Demist Mode is selected, air is

distributed from demist ducts only.

Figure 2F-15

Maximum Fan Relay

Purpose of test: To ensure a circuit exists between

the ECC module, the relay and the blower fan.

Pre-condition: Engine running.

Procedure: With T ECH 2 connected to DLC, s elect

Body / Electronic Climate Control / Miscellaneous

Tests / Maximum Fan Relay. Conduct Maximum

Fan Relay test by using the On soft key to activate

the relay and maximum fan speed and the Off soft

key to deactivate relay and turn blower speed off.

Figure 2F-16

Rear Demist Relay

Purpose of test: To check operation of circuit from

ECC control to relay.

Pre-condition: Engine not running.

Procedure: With T ECH 2 connected to DLC, s elect

Body / Electronic Climate Control / Miscellaneous

Tests / Rear Demist Relay. Conduct Rear Demist

Relay test by pressing the On soft key to activate

heated rear window relay; the rear demist button

will illuminate and ON will be dis played on the LCD

display. Use the Off s of t key to deactivate r elay; the

rear demist button illumination will go out and OFF

will be displayed on the LCD.

Figure 2F-17

Solenoids

NOTE:

If the TECH 2 Outlet Mode test was carried out and

passed this test need not be carried out.

Purpose of test: To ensure the ECC Module,

electrical circuit is OK.

Pre-condition: Engine not running.

Procedure: Remove the left side footwell upper

closing panel, locate the vacuum solenoid pack

(rear of blower housing). With TECH 2 connected

to DLC, select Body / Electronic Climate Control /

Miscellaneous Tests / Solenoids. Conduct

Solenoids test by Using the On soft key activate

one solenoid at a time.

Listen or feel for the solenoids activating (clicking).

Use the Off soft key to deactivate solenoids and

likewise listen or feel for solenoids activating

(clicking).

Figure 2F-18 shows the screen display for: solenoid

one, face level.

NOTE:

Refer to. Error! Reference source not found. to

understand which solenoid should be activated in

each mode.

Figure 2F-18

Figure 2F-19 shows the screen display for: solenoid

two, face level.

Figure 2F-19

Figure 2F-20 shows the screen display for: solenoid

one, foot level.

Figure 2F-20

Figure 2F-21 shows the screen display for: solenoid

two, foot level.

Figure 2F-21

Figure 2F-22 shows the screen display for the

fresh/recirculation solenoid.

Figure 2F-22

Figure 2F-23

A/C Request

Purpose of test: To ensure ECC Module, wiring,

compressor relay and compressor clutch are

functional.

Pre-condition: Engine running.

Procedure: With T ECH 2 connected to DLC, s elect

Body / Electronic Climate Control / Miscellaneous

Tests / A/C Request. Conduct A/C Request test by

using the On soft key to engage the compressor

clutch and the Off soft key to disengage the

compressor. Listen for clutch engagement noise.

NOTE:

In this test a blower fan speed is automatically

selected.

NOTE:

A three second delay until compressor clutch

engagement will occur, this is normal.

Figure 2F-24

F5: PROGRAM

In this mode, TECH 2 allows the programming of

the ECC control module.

W hen the Program option is selec ted, the following

two choices will be available:

Figure 2F-25

F0: Calibrate Air Mix Door – In this mode, the air

mix door(s) may be re-calibrated/programmed so

they dive to the full hot and full cold stops.

The calibration mode looks at the full movement in

either direction of the air mix doors/motors and

compares the actual voltage values to known base

values. If they are different, the ECC software will

compensate.

To calibrate the air mix door; connect TECH 2 to

DLC, select Body / Electronic Climate Control /

Program / Calibrate Air Mix Door and pres

Calibrate soft key on Tech 2.

When the air mix doors are re-calibrated TECH 2

will display the percentage of variation between the

base value and the pre-calibration value. If this

variation is greater than 5%, a noticeable dif f er enc e

should be felt and could have contributed to a

customer complaint.

NOTE: If programming is unsuccessful repeat the

program again, as th system may have crashed

during this process.

NOTE: During programm ing, a DTC 21 or 24 could

be set. If either of these codes are set, with TECH

2 connected, select Body / Electronic Climate /

Diagnostic Trouble Codes / Clear DTC Information

and clear DTC’s.

Figure 2F-26

F1: Program Code Index – In this mode, the code

index and program m ed c ode version ar e dis played,

as well as provide the operator the option of

reprogramming the code version.

Code Index:1 = Single Zone (SZ) Right Hand Drive.

2. = Dual Zone (DZ) Right Hand Drive.

Code Version:

The code version identifies the progrmmed level

ECC calibration. A Higher number indicates the

latest version of calibration and can be update

using TECH 2.

Figure 2F-27

There are two Options available in the calibration

mode:

1. Base Calibration – brings the ECC operating

parameters to the latest level.

NOTE: Although ECC Control modules are

supplied with a pre-programmed code version, in

some cases the TECH 2 software version maybe

latter, therefore, all new ECC control modules

should be reprogrammed using TECH 2. If the

ECC software version is latter than the TECH 2

base calibration version, TECH 2 will display

“TECH 2 does not include data f or this code index ”,

indicating that programming will not be necessary.

2. Custom Calibration – In this mode, the ECC

system programming function can be re-

calibrated to suit specific customers

complaints. (ie. Reduced Blower calibration

will re-program the blower motor to operate at

a slower speed to reduce airflow or blower

noise).

NOTE: Additional custom calibrations will be

available once established.

To calibrate the ECC control module, either Base

or Customer, connect TECH 2 to the DLC and

select Body / Electronic Climate Control / Pr ogram /

Program Code Index and press Modify soft key on

TECH 2. Select the appropriate calibration version

and press the Enter key.

NOTE: If programming is unsuccessful, repeat the

program again, as the system may have crashed

during this process

Figure 2F-28

1.3. S ENSOR ACCURACY TES T ING

When testing how accurate a sensor is relaying information, you will be required to probe onto the terminals of

either the sensor itself or the terminals of the ECC Module connector within that circuit using an ohmmeter.

For accurate temperature to ohms comparison readings use a digital multimeter placed close to the sensor itself.

1.4 DIAGNOSTIC CHARTS

INTRODUCTION

The following diagnostic charts are designed to provide fast and efficient fault location of the ECC system. Each

diagnostic chart consists of: a ‘diagnostic chart’ and pertinent information including Diagnostic Trouble Code (DTC)

setting parameters and, in most charts, circuit diagrams.

The following figures illustrate the terminal layout for the various connectors used in the ECC system. These figures

should be used in conjunction with the diagnostic chart circuit diagrams when checking circuit faults.

When carrying out wiring checks as directed to by the diagnostic charts, rather than probe terminals and connectors

with incorrect sized multimeter connections, use the adaptors contained in connector test adaptor kit KM-609. This

will prevent any possibility of spreading or damaging wiring harness terminals.

Ensure that at the completion of any diagnostic procedure, all diagnostic tools are removed and all ECC

components are correctly connected.

Techline

Figure 2F-29

Figure 2F-25

INTERMITTENTS

Definition: Problems may or may not turn the ξ symbol on in the ECC control module display or store a DTC,

indicating an intermittent problem. DO NOT use the diagnostic code charts for intermittent problems. When using

the code charts the fault must be present to locate the problem. If a fault is intermittent, use of diagnostic trouble

code charts may result in replacement of good parts.

• Most intermittent problems are caused by faulty electrical connections or wiring. Perform careful visual/physical

checks of the applicable circuit.

Check for:

1. Poor mating of the connector halves or terminal not fully seated in the connector body (backed out).

2. Improperly formed or damaged terminal. All connector terminals in the suspect circuit should be carefully

reformed or replaced to insure proper contact tension.

3. Poor terminal to wire connection. This requires removing the terminal from the connector body to check as

outlined in service operations.

4. ECC earth circuit terminals being loose.

• If a visual/physical check does not find the cause of the problem, the car can be driven with a voltmeter

connected to a suspected circuit. A scan tool (TECH 2) can also be used to help detect intermittent conditions.

An abnormal voltage, or scan tool reading, when the problem occurs, indicates the problem may be in that

circuit. If the wiring and connectors check OK, and a diagnostic trouble code was stored for a circuit having a

sensor, substitute a known good sensor and recheck.

• Loss of diagnostic code memory. To check, disconnect Ambient Air Temperature sensor and turn the ignition

on until the ξ symbol on in the ECC control module display comes on. DTC 13 should be stored, and kept in

memory when ignition is turned "OFF." If not, the ECC is faulty.

• Check for an electrical system interference caused by a defective relay, ECC driven solenoid, or switch. They

can cause a sharp electrical surge. Normally, the problem will occur when the faulty component is operated.

• Check for improper installation of non-factory installed electrical options such as lights, 2 way radios, etc.

• If problem has not been found, refer to the proper sy mptom and perform all checks listed there.

CHART A - DIAGNOSTIC CIRCUIT CHECK

CIRCUIT DESCRIPTION

When investigating any complaint of an ECC

problem or malfunction, always begin diagnosis

with the following diagnostic circuit check. This

check is a preliminary procedure that checks to

ensure the ECC is communicating on the serial

data line as well as helping to identify a problem or

malfunction and directing the reader to the

appropriate diagnostic chart in this Section.

With TECH 2 connected to the DLC and the

ignition switched on, TECH 2 should display serial

data communication. If TECH 2 does not display

serial data, the serial data circuit maybe open of

shorted.

There are several other control modules that are

connected to the serial data line (PCM, BCM,

ABS/ASR, ECC, instruments and SDM). Any one

of these control m odules c ould cause a f ault on the

serial data line. This fault could result in TECH 2

not being able to display serial data.

Test Description:

The numbers below refer to step numbers in

diagnostic chart ‘A’

1. This test checks if the ECC control module is

being powered up.

2. This test checks if the ECC control module has

detected and stored a current Diagnostic

Trouble Code.

3. This test determines if TECH is being powered

up.

4. This test checks if tech can communicate with

the ECC control module. If tech 2 cannot

communicate with the ECC control module, you

will not be able to determine which DTC has

been stored in the control module’s memory.

5. Determines which DTC has been stored in the

control module’s memory.

6. This test determines if a DTC was current and

has rectified. An intermittent problem has

caused this DTC to be stored.

7. During this test the ECC control module re-

calibrates the air mix doors, an incorrectly

calibrated air mix door will cause incorrect

operation of the ECC system.

8. Checks accuracy of ECC sensors.

9. During this test the operation of the air

conditioning section of the ECC system is

checked.

Notes on Diagnostic Chart:

1. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

2. Refer to 1.2 TECH 2 TEST MODES AND

DISPLAYS FOR ECC DIAGNOSIS in this

Section for further information on programming

of the ECC.

3. ECC sensors can be checked using the

following procedure and should als o be check ed

in the order as listed:

In car temperature sensor - connect TECH 2 to

DLC, select Body / Electronic Climate Control /

Data Display / Data List and scroll to In Car

Temperature Sensor. Using a digital

thermometer, placed as close to the in car

temperature sensor as possible, compare

thermometer reading with TECH 2 reading

(should be within ± 3°C). If values do not

correlate with each other, refer to

1.3 SENSOR ACCURACY TESTING in this

Section for a more accurate evaluation of the

sensor accuracy.

Ambient temperature sensor - connect TECH 2

to DLC, select Body / Electronic Clim ate Control

/ Data Display / Data List and scroll to Ambient

Temperature Sensor. Using a digital

thermometer, placed as close to the ambient

temperature sensor as possible, compare

thermometer reading with TECH 2 reading

(should be within ± 3°C). If values do not

correlate with each other, refer to

1.3 SENSOR ACCURACY TESTING in this

Section for a more accurate evaluation of the

sensor accuracy.

Sun sensor (sun sensor/remote receiver) refer

to DTC 19 diagnostic chart in this Section for a

procedure on checking this sensor.

Evaporator sensor - connect TECH 2 to DLC,

select Body / Electronic Climate Control / Data

Display / Data List and scroll to Evap

Temperature Sensor. Insert a digital

thermometer into the centre vent, start engine,

set A/C controls to full cold, fan speed 2 and

face level. Compare thermometer reading with

TECH 2 reading (thermometer reading should

be about 2 - 8°C higher than TECH 2 reading). If

values do not correlate with each other, refer to

1.3 SENSOR ACCURACY TESTING in this

Section for a more accurate evaluation of the

sensor accuracy.

STEP ACTION VALUE YES NO

1. • Turn ignition on.

• Turn on ECC system.

• Does ECC system

display activate?

Go to step 2. Go to Chart B -

ECC SYSTEM

DOES NOT

POWER UP is this

Section.

2. • Is there an X in the

bottom RH corner of the

ECC display?

Go to step 3. Go to step 6.

3. • Connect TECH 2 to the

DLC (refer Note 1).

• Turn ignition on.

• Push power button on

TECH 2.

• Does TECH 2 power up

(screen will illuminate

display TECH 2)?

Go to Step 4. Go to TECH 2

diagnosis, refer to

Section 0C -

TECH2.

STEP ACTION VALUE YES NO

4. • At the TECH 2 title

screen press the Enter

key.

• Select: Diagnostics

\1997 \ VT Commodore

\ Body \ Electronic

Climate Control.

• Turn on ignition and

press the confirm soft

key.

• Does TECH 2 display

ECC System

Identification Screen

information (ie. part

number etc.)?

Go to step 5. Go to DTC 39

SERIAL DATA

INTERFACE

FAULT in this

Section.

5. • With TECH 2 still

connected, ignition on

and ECC system

selected.

• Select: Diagnostic

Trouble Codes \ Read

Current DTC

Information.

• Does TECH 2 display

any DTC’s?

Go to applicable

DTC Chart in this

Section.

Go to step 6.

6. • With TECH 2 still

connected, ignition ON,

• Select Diagnostic

Trouble Codes \ Read

History DTC

Information.

• Does Tech 2 display

any History DTC’s?

DTC is intermittent.

Refer to

INTERMITTENTS

in this Section.

Go to step 7.

7. • With TECH 2 still

connected, ignition on

and ECC system

selected.

• Select Program \

Calibrate Air Mix Door \

Calibrate.

• Is the Air Mix Door

Position Difference

greater than specified

value (refer Note 2)?

5 % ECC Air Mix Doors

have been re-

calibrated.

Verify Repair.

Go to step 8.

8. • Check the accuracy of

the ECC sensors (refer

Note 3)

• Are ECC sensors OK?

Go to Step 9 Replace faulty ECC

sensor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALL.

9. • Perform HARRISON V5

COMPRESSOR TXV

SYSTEM DIAGNOSIS

refer to Section 2C.

• Does system pass

Diagnosis Test?

No fault found with

ECC system.

System Code

Index may need to

be Programmed

refer to

Programming

Code Index in this

Section.

Carry out repair

procedure as

detailed in Harrison

V5 Compressor

TXV System

Diagnosis,

refer to

Section 2C.

CHART B - ECC SYSTEM DOES NOT POWER UP

Figure 2F-26

CIRCUIT DESCRIPTION

Battery power is supplied to the ECC control module, terminal 4, with the ignition switch in the IGN or START

positions through fuse F13 (located in the passenger compartment fuse panel).

TEST DESCRIPTION:

The numbers below refer to step numbers in diagnostic chart ‘B’

1. The diagnostic circuit test is the beginning of all diagnostic and should be performed whenever diagnosing an

ECC system complaint.

2. This test checks if the fuse F13 is OK.

3. This test determines if power is being supplied to fuse F13.

4. This test determines if the ECC control has a power supply and an earth. If the control module has power and

earth and the module is not being activated when the ignition and the ECC system is turned on.

5. If battery voltage was not available during step 4, this test determines if the power supply circuit 44 to the ECC

control module has continuity.

6. If battery voltage was not available during step 4, this test determines if the earth circuit 155 to the ECC control

module has continuity.

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for procedures on checking wiring faults.

STEP ACTION VALUE YES NO

1. • Has Diagnostic Circuit

Check been performed? Go to step 2 Go to Chart A -

DIAGNSOTIC

CIRCUIT CHECK

in this Section.

2. • Check Fuse F13.

• Is fuse F13 OK? Go to step 3. Replace fuse and

check for cause of

blown fuse.

Recheck and verify

repair.

3. • Turn Ignition on.

• Using a DVM check for

voltage at fuse F13

circuit 3 (Pink wi re)

(refer Note 1).

• Is voltage at specified

value?

B+ Go to step 4. Repair open in

circuit 3 pink wire.

Recheck and verify

repair..

4. • Remove ECC control

module (refer Section

2E ECC REMOVAL

AND INSTALLATION).

• Turn Ignition on.

• Using a DVM check for

voltage between ECC

Control module

connector YB87

terminal 4 circuit 44

(Pink / Blue wire) and

YB87 terminal 2 circuit

155 (Black / Yellow

wire) (refer Note 1).

• Is voltage at specified

value?

B+ Replace ECC

Control Module,

refer to Section

2E AIR

CONDITIONING -

ECC - REMOVE &

INSTALL.

Go to step 5.

5. • Ignition off.

• Using an ohmmeter

check continuity of

circuit 44 (Pink / Blue

wire) between ECC

module connector

YB87, terminal 4 and

fuse F13 (refer

Note 1).

• Is there continuity ?

Go to step 6. Repair open in

circuit 44 (Pink /

Blue wire) between

ECC control

module connector

YB87 and fuse

F13. Recheck and

verify repair.

6. • Ignition off.

• Using an ohmmeter

check continuity of

circuit 155 (Black /

Yellow wire) between

ECC module connector

YB87 and known good

earth (refer Note 1).

• Is there continuity ?

Check for

intermittent

connection at ECC

module connector

YB87. Check sizing

of connector YB87

terminals.

Repair open in

circuit 155 (Black /

Yellow wire)

between ECC

module connector

YB87 and earth

LOC. 3. Recheck

and verify repair.

DTC 13 - AMBIENT AIR TEMPERATURE SENSOR (ATS) - SIGNAL VOLTAGE HIGH

Figure 2F-27

CIRCUIT DESCRIPTION:

The Ambient Temperature Sensor (ATS) uses a thermistor to control the signal voltage to the ECC Module. The

ECC Module applies a voltage of 3.2 ±0.2 volts to the sensor when the air is cold, the ATS resistance is high

therefore the ECC Module will sense a high signal voltage. If the ambient air is warm, the ATS resistance is low

therefore the ECC Module will sense a low signal voltage.

DTC 13 will set if: the ATS sensor signal voltage is more than 3.5 ±0.2 volts or, if the ATS sensor, wiring harness

(circuit 735) or connectors are open circuited.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. Checks that the conditions for setting the DTC

are present or if fault is intermittent.

3. Checks integrity of circuit 735.

4. Checks if sensor is okay by testing resistance

across ATS.

5. Checks for an intermittent connection at ATS.

6. Checks for an open in circuit 155.

7. Checks for an open in circuit 735.

8. Checks for short to voltage in circuit 735.

DIAGNOSTIC AIDS:

The default temperature for an open circuit is 22.5°C.

If the vehicle is left idling for an extended period, the

ambient temperature readings will rise owing to heat

radiated by the A/C Condenser and lack of airflow.

When using the temperature/resistance chart below,

place a thermometer as close as possible to the

sensor being tested, com pare this temperature figure

taken to the resistance value.

Notes on Diagnostic Chart:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

TEMPERATURE RESISTANCE CHART

AMBIENT°

°°

°CRESISTANCE AMBIENT°

°°

°CRESISTANCE

0 15920 - 16750 40 2610 - 2717

10 9715 - 10193 50 1767 - 1836

20 6107 - 6389 60 1201 - 1291

30 3943 - 4115

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to

DLC (refer to Note 2).

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to Ambient Air

Temperature Sensor.

• Does TECH 2 display

Ambient Air

Temperature Sensor

above specified value?

3.4 Volts Go to Step 3. DTC 13

intermittent. If no

additional DTCs

were stored,

refer to

INTERMITTENT

in this section

3• With TECH 2 still

connected and Ambient

Air Temperature Sensor

displayed, disconnect

ambient air temperature

sensor wiring harness

connector YE73.

• Place a jumper wire

between the two

terminals of connector

YE73.

• Does TECH 2 display

ambient air temperature

sensor below the

specified value?

0.4 Volts Go to Step 4. Go to Step 6

4• With the ambient air

temperature sensor

wiring harness

connector YE73

disconnected, check

resistance across

ambient air sensor

terminals (refer to

Note 1).

• Is value as specified?

Refer to

Temp.

Resistance

Chart.

Go to Step 5. Replace faulty

ambient air

temperature

sensor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

STEP ACTION VALUE YES NO

5• Inspect ambient air

temperature sensor

wiring harness

connector YE73 for an

intermittent or loose

terminal.

• Is connector YE73

okay?

Repair connector

as necessary.

Recheck and

verify repair

Go to Step 8

6• With TECH 2 still

connected and Ambient

Air Temperature Sensor

displayed, connect a

jumper lead between

circuit 735 (Light Green

/ Blue wire) and chassis

ground.

• Does TECH 2 display

ambient air temperature

sensor below the

specified value?

0.4 Volts Check and repair

open in circuit

155 (ATS earth).

Recheck and

verify repair.

Go to Step7

7• Check continuity of

circuit 735 (Light Green

/ Blue wire) between

connectors YE73 and

YB87 (including

connectors) (refer to

Note 1).

• Does continuity exist

and is connection okay?

Check and repair

circuit 735 as

necessary.

Recheck and

verify repair.

Go to Step 8

8• Turn ignition OFF.

• Disconnect ECC wiring

harness connectors

YB87 & YB89.

• Remove jumper lead

from ambient air

temperature sensor

connector YE73.

• Turn ignition ON.

• Check Voltage between

circuit 735 (Light Green

/ Blue wire) and chassis

ground at ambient air

temperature sensor

wiring harness

connector YE73.

• Was voltage below

specified value?

0.4 Volts Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

Check and repair

short to voltage in

circuit 735.

Recheck and

verify repair.

DTC 14 - AMBIENT AIR TEMPERATURE SENSOR (ATS) - SIGNAL VOLTAGE LOW

Figure 2F-28

CIRCUIT DESCRIPTION:

The ambient air temperature sensor (ATS) uses a

thermistor to control the signal voltage to the ECC

Module. The ECC Module applies a voltage of 3.5

±0.2 volts to the sensor when the air is cold, the

ATS resistance is high therefore the ECC Module

will sense a high signal voltage. If the air is warm,

the ATS resistance is low therefore the ECC

Module will sense a low signal voltage.

DTC 14 will set if: the AT S sensor signal voltage is

less than 0.3 volts or, if the ATS sensor, wiring

harness (circuit 735) or connectors are short

circuited.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. This test checks that the conditions that would

set the DTC are present.

3. This test checks if the sensor is causing the

short circuit.

4. This test checks if sensor is functioning okay.

5. Checks for intermittent connection at sensor.

6. Checks for a shor t c irc uit of sens or signal wire to

earth.

DIAGNOSTIC AIDS:

The default temperature for a short circuit is 22.5°C.

If the vehicle is left idling for an extended period, the

ambient temperature readings will rise owing to heat

radiated by the A/C Condenser and lack of airflow.

When using the temperature/resistance chart below,

place a thermometer as close as possible to the

sensor being tested, com pare this temperature figure

taken to the resistance value.

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

TEMPERATURE RESISTANCE CHART

AMBIENT°

°°

°CRESISTANCE AMBIENT°

°°

°CRESISTANCE

0 15920 - 16750 40 2610 - 2717

10 9715 - 10193 50 1767 - 1836

20 6107 - 6389 60 1201 - 1291

30 3943 - 4115

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to DLC

(refer to Note 2).

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to Ambient Air

Temperature Sensor.

• Does TECH 2 display

Ambient Air

Temperature Sensor

less than specified

value?

0.4 Volts Go to Step 3. DTC 14

intermittent. If no

additional DTCs

were stored,

refer to

INTERMITTENTS

in this section.

3• With TECH 2 still

connected and Ambient

Air Temperature Sensor

displayed, disconnect

ambient air temperature

sensor wiring harness

connector YE73.

• Does TECH 2 display

ambient air temperature

sensor above the

specified value?

3.4 Volts Go to Step 4. Go to Step 6.

4• With the ambient air

temperature sensor

wiring harness connector

YE73 disconnected,

check resistance

across ambient air

sensor terminals (refer

to Note 1).

• Is value as specified?

Refer to

Temp.

Resistance

Chart.

Go to Step 5. Replace faulty

ambient air

temperature

sensor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

5• Check for intermittent

short to ground in

ambient air temperature

sensor circuit 735 (Light

Green / Blue wire)

including connectors

YE73 or YB87 (refer to

Note 1 on previous

chart).

• Was a problem found?

Repair fault as

necessary.

Recheck and

verify repair.

Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

6• Check circuit 735 (Light

Green / Blue wire) for

short to earth (refer to

Note 1 on previous

chart).

• Was a problem found?

Repair fault as

necessary.

Recheck and

verify repair.

Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

DTC 15 - IN-CAR TEMPERATURE SENSOR (ITS) - SIGNAL VOLTAGE HIGH

Figure 2F-29

CIRCUIT DESCRIPTION:

The In-car Temperature Sensor (ITS) is a

thermistor used to vary voltage signals to the

control the signal voltage to the ECC Module. The

ECC Module applies a voltage of 3.5 ±0.2 volts to

the sensor, via circuit 734. When the vehicle

interior air is cold, the ITS resistance is high

therefore the ECC Module will sense a high signal

voltage. If the air is warm, the ITS resistance is low,

therefore the ECC Module will sense a low signal

voltage.

DTC 15 will set: if the ITS signal voltage is more

than 3.5 ±0.2 volts or, if the ITS sensor, wiring

harness (circuit 734) or connectors are open

circuited

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. Checks that the conditions for setting the DTC

are present or if fault is intermittent.

3. Checks integrity of circuit 734.

4. Checks if sensor is okay by testing resistance

across ITS.

5. Checks for an intermittent connection at ITS.

6. Checks for an open in circuit 155.

7. Checks for an open in circuit 734.

8. Checks for short to voltage in circuit 734.

DIAGNOSTIC AIDS:

The default temperature for an open circuit is 22.5°C.

When using the temperature/resistance chart below,

place a thermometer as close as possible to the

sensor being tested, com pare this temperature figure

taken to the resistance value.

Notes on Diagnostic Chart:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

TEMPERATURE RESISTANCE CHART

AMBIENT°

°°

°CRESISTANCE AMBIENT°

°°

°CRESISTANCE

5 7009 - 7536 30 2175 - 2299

10 5477 - 5856 35 1746 - 1857

15 4310 - 4583 40 1410 - 1508

20 3416 - 3612 45 1145 - 1231

25 2725 - 2865 50 935 - 1010

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to

DLC (refer to Note 2).

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to In-car

Temperature Sensor.

• Does TECH 2 display

In-car Temperature

Sensor above specified

value?

3.4 Volts Go to Step 3. DTC 15

intermittent. If no

additional DTCs

were stored,

refer to

INTERMITTENT

in this section

3• With TECH 2 still

connected and In-car

Temperature Sensor

displayed, disconnect

in-car temperature

sensor wiring harness

connector YB91.

• Place a jumper wire

between the two

terminals of connector

YB91.

• Does TECH 2 display

In-car temperature

sensor below the

specified value?

0.4 Volts Go to Step 4. Go to Step 6

4• With the in-car

temperature sensor

wiring harness

connector YB91

disconnected, check

resistance across in-car

temperature sensor

terminals (refer to Note

1).

• Is value as specified?

Refer to

Temp.

Resistance

Chart.

Go to Step 5. Replace faulty in-

car temperature

sensor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

STEP ACTION VALUE YES NO

5• Inspect in-car

temperature sensor

wiring harness

connector YB91 for an

intermittent or loose

terminal.

• Is connector YB91

okay?

Repair connector

as necessary.

Recheck and

verify repair

Go to Step 8

6• With TECH 2 still

connected and In-car

Temperature Sensor

displayed, connect a

jumper lead between

circuit 734 (Blue/Black

wire) and chassis

ground.

• Does TECH 2 display

In-car Temperature

Sensor below the

specified value?

0.4 Volts Check and repair

open in circuit

155 (ITS earth).

Recheck and

verify repair.

Go to Step7

7• Check continuity of

circuit 734 (Blue/Black

wire) between

connectors YB91 and

YB87 (including

connectors) (refer to

Note 1).

• Does continuity exist

and is connection okay?

Go to Step 8. Check and repair

circuit 734 as

necessary.

Recheck and

verify repair.

8• Turn ignition OFF.

• Disconnect ECC wiring

harness connectors

YB87 & YB89.

• Remove jumper lead

from i n-car temperature

sensor connector YB91.

• Turn ignition ON.

• Check Voltage between

circuit 734 (Blue/Black

wire) and chassis

ground at in-car

temperature sensor

wiring harness

connector YB91.

• Was voltage below

specified value?

0.4 Volts Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

Check and repair

short to voltage in

circuit 734.

Recheck and

verify repair.

DTC 16 - IN-CAR TEMPERATURE SENSOR (IAT) - SIGNAL VOLTAGE LOW

Figure 2F-30

CIRCUIT DESCRIPTION:

The in-c ar tem perature s ensor ( ITS) is a therm istor

used to vary voltage signals to the ECC Module.

The ECC Module applies a voltage of 3.5 ±0.2 volts

to the sensor. W hen the vehicle interior air is cold,

the ITS resistance is high therefore the ECC

Module will sense a high signal voltage. If the air is

warm, the IT S resistanc e is low, therefore the ECC

Module will sense a low signal voltage.

DTC 16 will set: if the ITS signal voltage is less

than 0.3 volts or, if the ITS sensor, wiring harness

(circuit 734) or connectors are short circuited

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. This test checks that the conditions that would

set the DTC are present.

3. This test checks if the sensor is causing the

short circuit.

4. This test checks if sensor is functioning okay.

5. Checks for intermittent connection at sensor.

6. Checks for a shor t c irc uit of sens or signal wire to

earth.

DIAGNOSTIC AIDS:

The default temperature for a short circuit is 22.5°C.

When using the temperature/resistance chart below,

place a thermometer as close as possible to the

sensor being tested, com pare this temperature figure

taken to the resistance value.

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

TEMPERATURE RESISTANCE CHART

AMBIENT°

°°

°CRESISTANCE AMBIENT°

°°

°CRESISTANCE

5 7009-7536 30 2175-2299

10 5477-5856 35 1746-1857

15 4310-4583 40 1410-1508

20 3416-3612 45 1145-1231

25 2725-2865 50 935-1010

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to

DLC (refer to Note 2).

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to In-car

Temperature Sensor.

• Does TECH 2 display

In-car Temperature

Sensor less than

specified value?

0.4 Volts Go to Step 3. DTC 16

intermittent. If no

additional DTCs

were stored,

refer to

INTERMITTENTS

in this section.

3• With TECH 2 still

connected and In-car

Temperature Sensor

displayed, disconnect

in-car temperature

sensor wiring harness

connector YB91.

• Does TECH 2 display

In-car Temperature

Sensor above the

specified value?

3.4 Volts Go to Step 4. Go to Step 6.

4• With the in-car

temperature sensor

wiring harness

connector YB91

disconnected, check

resistance across in-car

sensor terminals (refer

to Note 1).

• Is value as specified?

Refer to

Temp.

Resistance

Chart.

Go to Step 5. Replace faulty in-

car temperature

sensor, refer to

Section 2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

5• Check for intermittent

short to ground in in-car

temperature sensor

circuit 734 (Blue / Black

wire) including

connectors YB91 or

YB87 (refer to Note 1).

• Was a problem found?

Repair fault as

necessary.

Recheck and

verify repair.

Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

6• Check circuit 734 (Blue

/ Black wire) for sho rt to

earth (refer to Note 1).

• Was a problem found?

Repair fault as

necessary.

Recheck and

verify repair.

Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

DTC 17 - EVAPORATOR AIR TEMPERATURE SENSOR (ETS) - SIGNAL VOLTAGE HIGH

Figure 2F-31

CIRCUIT DESCRIPTION:

The Evaporator Tem perature Sensor (ETS) uses a

thermistor to vary voltage signals to the ECC

Module. The ECC Module applies a voltage of 3.6

±0.18 volts to the sensor. W hen the air is cold, the

ETS resistance is high, therefore the ECC Module

will sense a high signal voltage. If the air is warm

the resistance is low, therefore the ECC Module

will sense a low signal voltage .

DTC 17 will set: if the ETS signal voltage is more

than 3.4 volts or, if the ETS sensor, wiring har ness

(circuit 783) or connectors are open circuited

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. This test checks that the conditions that would

set the DTC are present

3. This test checks if the wiring or sensor is open

circuit

4. This test checks if wiring is shorted to the ignition

feed in the ECC harness.

5. This test checks if wiring is shorted to the 3.5 V

feed in the ECC harness.

6. This test checks if wiring is shorted to a voltage

in the main wiring harness.

7. Check for intermittent connection at ECC.

8. This test checks if sensor is functioning okay.

9. Check for intermittent connection at sensor

10. This test checks for an open circuit sensor ear th

wire.

This test checks for an open circuit sensor signal

wire.

DIAGNOSTIC AIDS:

The default temperature for an open circuit is 5°C.

When using the temperature/resistance chart below,

place a thermometer in the centre vent, set

temperature to full cold and manual fan speed to 2.

This will give an approximate evaporator air

temperature. Compare this figure taken to the chart

below.

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

TEMPERATURE RESISTANCE CHART

AMBIENT°

°°

°CRESISTANCE AMBIENT°

°°

°CRESISTANCE

5 4300 - 4850 30 1675 - 1850

10 3600 - 4050 35 1330 - 1470

15 2950 - 3250 40 1140 - 1260

20 2320 - 2625 45 950 - 1050

25 1990 - 2200 50 850 - 950

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to

DLC (refer to Note 2).

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to Evap

Temperature Sensor.

• Does TECH 2 display

Evap Temperature

Sensor above specified

value?

3.4 Volts Go to Step 3. DTC 17

intermittent. If no

additional DTCs

were stored,

refer to

INTERMITTENT

in this section

3• Disconnect ECC

connector YB89

• Check resistance

across evap air

temperature sensor

terminals at ECC

connector YB89 pins 19

& 15 (refer to Note 1).

• Is value as specified?

Refer to

Temp.

Resistance

Chart.

Go to Step 4. Go to Step 8.

4• With ECC connector

YB89 disconnected,

measure the resistance

between ECC harness

connector YB89

terminals 5 & 19

(circuits 367 & 763).

• Does a short exist?

NOTE:

Any resistance measured

here qualifies as a short

Ohms Repair short in

circuits 367 and

763. Recheck and

verify repair.

Go to Step 5.

5• With ECC connector

YB89 disconnected,

measure the resistance

between ECC harness

connector YB89

terminals 11 & B19

(circuits 188 & 763).

• Is the resistance less

than specified value?

4 K Ohms Repair short in

circuits 188 and

763. Recheck and

verify repair.

Go to Step 6.

6• Turn ignition ON.

• Check voltage across

circuit 763 to chassis

ground at ECC harness

connector YB89.

• Was voltage below

specified value?

0.4 Volts Go to Step 7. Repair short to

voltage in circuit

763. Recheck and

verify repair.

7• Inspect ECC harness

connector YB89 for an

intermittent or loose

terminal.

• Is connector YB89

okay?

Repair connector

as necessary.

Recheck and

verify repair.

Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

STEP ACTION VALUE YES NO

8• Disconnect ETS

connector YB55.

• Check resistance

across evap air

temperature sensor

terminals (refer to

Note 1).

• Is value as specified?

Refer to

Temp.

Resistance

Chart.

Go to Step 9. Replace faulty in-

evap temperature

sensor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

INSTALLATION.

9• Inspect evap air

temperature sensor

harness connector

YB55 for an intermittent

or loose terminal.

• Is connector YB55

okay?

Repair connector

as necessary.

Recheck and

verify repair.

Go to Step 10.

10 • Check continuity of

circuit 62 (Tan wire)

between connectors

YB55 and YB89

(including connectors)

(refer to Note 1).

• Does continuity exist

and is connection okay?

•

Go to Step 11. Check and repair

circuit 62 as

necessary.

Recheck and

verify repair.

11 • Check continuity of

circuit 763 (White/Black

wire) between

connectors YB55 and

YB89 (including

connectors) (refer to

Note 1).

• Does continuity exist

and is connection okay?

Reconnect evap

air temp sensor

harness

connector YB55

and go to

step 4.

Check and repair

circuit 763 as

necessary.

Recheck and

verify repair.

DTC 18 - EVAPORATOR AIR TEMPERATURE SENSOR (ETS) - SIGNAL VOLTAGE LOW

Figure 2F-32

CIRCUIT DESCRIPTION:

The evaporator temperature sensor (ETS) uses a

thermistor to control the signal voltage to the ECC

Module. The ECC Module applies a voltage of 3.6

±0.18 volts to the sensor when the air off the

evaporator cor e is c old, the ETS r esistanc e is high,

therefore the ECC Module will sense a high signal

voltage. If the air is warm, the ETS resistance is

low, therefore the ECC Module will sense a low

signal voltage.

DTC 18 will set: if the ETS signal voltage is less

than 0.3 volts or, if the ETS sensor, wiring har ness

(circuit 783) or connectors are short circuited.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. This test checks that the conditions that would

set the DTC are present

3. This test checks if the sensor or wiring is

causing the short circuit

4. This test checks if sensor & wiring is functioning

okay.

5. Check for intermittent connection at sensor

6. This test checks for a short circuit of the sensor

signal wire to earth.

7. This test determines if the sensor is shorted or

the wire is shorted.

DIAGNOSTIC AIDS:

The default temperature for a short circuit is 5°C.

When using the temperature/resistance chart below,

place a thermometer in the centre vent, set

temperature to full cold and manual fan speed to 2.

This will give an approximate evaporator air

temperature. Compare this figure taken to the chart

below.

Notes on Diagnostic Chart:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

TEMPERATURE RESISTANCE CHART

AMBIENT°

°°

°CRESISTANCE AMBIENT°

°°

°CRESISTANCE

5 4300 - 4850 30 1675 - 1850

10 3600 - 4050 35 1330 - 1470

15 2950 - 3250 40 1140 - 1260

20 2320 - 2625 45 950 - 1050

25 1990 - 2200 50 850 - 950

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to

DLC (refer to Note 2).

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to Evap

Temperature Sensor.

• Does TECH 2 display

Evap Temperature

Sensor less specified

value?

0.4 Volts Go to Step 3. DTC 18

intermittent. If no

additional DTCs

were stored,

refer to

INTERMITTENTS

in this section

3• With TECH 2 connected

and Evap Temperature

Sensor displayed,

disconnect ECC wiring

harness YB89.

• Does TECH 2 display

Evap Temperature

Sensor above specified

value?

3.4 Volts Go to Step 4. Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

4• Disconnect ECC

connector YB89

• Check resistance

across evap air

temperature sensor

terminals at ECC

connector YB89 pins 19

& 15 (refer to Note 1).

• Is value as specified?

Refer to

Temp.

Resistance

Chart.

Go to Step 5. Wiring or Sensor

Faulty

Go to Step 7

STEP ACTION VALUE YES NO

5• With ECC connector

YB89 disconnected,

measure the resistance

between ECC harness

connector YB89

terminal 19 (circuit 763)

and ground.

• Does a short exist?

NOTE:

Any resistance measured

here qualifies as a short

Ohms Repair short in

circuit 763.

Recheck and

verify repair.

Go to Step 6

6• Inspect ECC and evap

air temperature sensor

wiring harness

connectors YB55 and

YB89 for an intermittent

short in harness or

connectors.

• Are connectors YB55 an

YB89 okay?

Repair connector

as necessary.

Recheck and

verify repair.

Replace faulty

ECC control

module, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

7• Disconnect ETS sensor

plug YB55

• Connect YB87 & YB89

connectors to ECC

• Connect TECH 2 to

DLC.

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to Evap

Temperature Sensor.

• Does TECH 2 display

Evap Temperature

Sensor above specified

value?

3.4 Volts Replace faulty in-

evap

temperature

sensor, refer to

Section 2E AIR

CONDITIONING

- ECC -

REMOVAL &

INSTALLATION.

Repair short to

ground in circuit

763. Recheck and

verify repair.

DTC 19 - SUN LOAD SENSOR FAULT

Figure 2F-33

CIRCUIT DESCRIPTION:

The sun load sensor is mounted in the instrument

panel pad between the demist duc ts to monitor the

amount of sun load and am bient light in f ront of the

vehicle. The am bient light m onitored is us ed by the

BCM for Auto Lights O n operation ( twilight s entinel)

and the sun load monitored is used by the ECC

control module. The BCM monitors the voltage

from this sensor via circuit 272 and converts this

voltage signal into steps which it s ends to the ECC

control module via the auxiliary serial data line,

circuit 1220. T he m es sage sent will vary between 0

and 254 steps depending on the amount of sun

load (0 = no sun load, 254 = maximum sun load).

DTC 19 will set if the BCM sends a sun load sensor

value of 255 steps to the ECC c ontrol m odule. T he

BCM will send this value if it detects a high sun

load and a low twilight level.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2 & 3. Uses TECH 2 to check ambient light level

data on the auxiliary serial data bus.

4 & 5. Uses TECH 2 to check ambient light level

signal at microprocessor of BCM.

6. Determines if the sun sensor / remote receiver

module has power and earth by checking

operation of the remote coded key reader.

7 & 8. Checks ambient light level signal at input to

BCM.

9. Checks integrity of circuit 272 (open, short to

earth or short to B+).

10. Checks battery voltage supply at sun sensor /

remote receiver module.

11. Checks integrity of circuit 271 (open, short to

earth or short to B+).

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to

DLC (refer to Note 2).

• Select Body / Body

Control Module / Normal

Mode and scroll to

Ambient Light Level.

• Cover the sun load

sensor / remote receiver

module assembly.

• Does TECH 2 display 1

Step

Go to Step 3. Go to Step 4.

3• With TECH 2 connected

and Ambient Light Level

displayed, shine a torch

directly on the sun load

sensor / remote receiver

module assembly.

• Does TECH 2 display

254 Step

Fault not found, if

no other DTCs are

stored, refer to

INTERMITTENTS

in this section.

Go to Step 4.

4• With TECH 2

connected, select Body

/ Body Control Module /

Data Display / Datal List

and scroll to Ambient

Light Sensor display

• Cover the sun load

sensor / remote receiver

module assembly.

• Is TECH 2 screen

display value as

specified?

Less than

0.5 volts Replace BCM,

refer to Section

12J-2 HIGH

SERIES BCM.

Go to Step 5.

STEP ACTION VALUE YES NO

5• With TECH 2

connected, and Ambient

Light Sensor displayed

• Shine a torch on the sun

load sensor / remote

receiver module

assembly.

• Is TECH 2 screen

display value as

specified?

Approx.

5 volts Replace BCM,

refer to Section

12J-2 HIGH

SERIES BCM.

Go to Step 6.

6• Check operation of the

remote coded key

receiver by locking and

unlocking the doors

using the remote coded

key Lock and Unlock

button.

• Does remote coded key

receiver operate?

Go to Step 7 Go to Step 10.

7• Back probe BCM

connector YB175,

terminal E10, circuit 272

(Yellow/Black wire) with

a voltmeter to earth

(referNOTE 1).

• Turn ignition ON.

• Cover the sun load

sensor / remote receiver

module assembly.

• Is voltage as specified?

Less than

0.5 volts Replace BCM,

refer to Section

12J-2 HIGH

SERIES BCM.

Go to Step 8.

STEP ACTION VALUE YES NO

8• Back probe BCM

connector YB175,

terminal E10, circuit 272

(Yellow/Black wire) with

a voltmeter to earth

(refer NOTE 1).

• Turn ignition ON.

• Shine a torch on the sun

load sensor / remote

receiver module

assembly.

• Is voltage as specified?

Approx.

5 volts Replace BCM,

refer to Section

12J-2 HIGH

SERIES BCM.

Go to Step 9.

9• Check integrity of circuit

272 (Yellow/Brown wire)

(refer NOTE 1).

• Is circuit 272 okay?

Replace sun

sensor / remote

receiver module,

refer to Section

12J-2 HIGH

SERIES BCM

Check and repair

circuit 272 as

necessary.

Recheck and verify

repair.

10 • Back probe sun sensor /

remote receiver module

connector YB95, circuit

740 (Orange/Black wire)

with a voltmeter to earth

(refer NOTE 1).

• Is voltage as specified?

12 volts Go to Step 11. Check and repair

circuit 740.

Recheck and verify

repair.

11 • Check integrity of circuit

271 (Brown/Green wire)

(refer NOTE 1).

• Is circuit 271 okay?

Go to Step 7. Check and repair

circuit 271.

Recheck and verify

repair.

DTC 21 - AIR MIX MOTOR DRIVERS SIDE (SZ/DZ)

Figure 2F-39

CIRCUIT DESCRIPTION:

The air m ix motor is actually an electric m otor used

to operate the air m ixing door. T he electr ic m otor is

sent a voltage signal of 12.5 volts from the ECC

control module which causes the motor to turn,

which moves the air mix door towards or away

from the heater core, the direction change takes

place by reversing the polarity of this motor.

A potentiometer (PBR) is housed in the air mix

motor circuit which feeds signals (3.6 ± 0.18 volts)

back to the ECC control module as to the

positioning of the motor and consequently the air

mix door.

DTC 21 will set: if the dr iver’s PBR feedbac k signal

fails to r each the requested value. T his will occur if

the PBR or motor is open or short circuited, or if

the air mix door is jammed or sticking.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. This test checks that the DTC is current.

3. This test checks if the motor is moving

4. This test checks that the m otor is stopping within

the correct range @ full cold.

5. This test checks that the m otor is stopping within

the correct range @ full hot.

6. Attempts to re-calibrate & check DTC is still

current

7. Determines if a motor fault is more likely than a

PBR fault to be the cause of the problem.

8. Checks fault has been rectified.

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

DIAGNOSTIC AIDS:

An air mix motor or door problem will always be

associated with non-regulated or incorrect

temperatures from mode positions.

The ECC control module, during calibration, sets a

minimum and a maximum PBR value for the air mix

motor in it’s memory. It is these values which

determine the operating range of the air mix motor

and against which all movements of the air mix

adjustm ent are scaled. Any PBR signal value outside

the minimum or maximum vale are considered a

motor fault.

The ECC c ontrol module m onitors the rate of change

of PBR signal during air mix motor movement. If this

rate of change falls to 0 (such as a broken air mix

motor wire or physical jam b), the ECC contr ol m odule

will recognise the stoppage and set the fault code.

If DTC 21 was present before turning the ignition off,

when the ignition is turned on again, the ECC control

m odule will autom atically try to re-c alibrate the air m ix

door. This takes approxim ately 15 seconds. If the re-

calibration fails, then DTC 21 will be set again.

DTC 21 - AIR MIX MOTOR DRIVERS SIDE

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Turn ignition OFF.

• Connect TECH 2 to

DLC.

• Turn ignition ON when

instructed by TECH 2.

• Select Body / Electronic

Climate Control /

Diagnostic Trouble

Codes / Read Current

DTC Information.

• Is DTC 21 displayed as

a current DTC?

Go to Step 3. Go to Step 8.

3• With TECH 2 still

connected, select Body

/ Electronic Climate

Control / Miscellaneous

Tests / Drivers S ide A ir

Mix Motor - Door

Movement and increase

to maximum then

decrease to minimum.

• Does the Drivers Air Mix

Door feedback (voltage)

on TECH 2 change?

Go to Step 4. Go to Step 7.

4• With Driver’s Side Air

Mix Motor - Door

Movement test still

selected, decrease air

mix door to minimum.

• Does Tech 2 display

Drivers Air Mix Door

feedback within the

specified range?

0.6 to 0.9

Volts Go to Step 5. Go to following

chart DRIVER

MOTOR TEST in

this Section.

STEP ACTION VALUE YES NO

5• With Driver’s Side Air

Mix Motor - Door

Movement test still

selected increase air

mix door to maximum.

• Does Tech 2 display

Drivers Air Mix Door

feedback within the

specified range?

2.6 to 2.9

Volts Go to Step 6. Go to following

chart DRIVER

MOTOR TEST in

this Section.

6• With TECH 2 still

connected, select Body

/ Electronic Climate

Control / Program /

Calibrate Air Mix Door

and reprogram air mix

doors.

• Turn ignition OFF.

• Turn ignition ON.

• Is DTC-21 set as a

current DTC?.

Go to following

chart DRIVER

MOTOR TEST in

this Section.

Go to Step 8.

7. • In Step 3, did TECH 2

display Drivers Air mix

door feedback within the

specified range?

0.3 to 3.4

volts Go to following

chart DRIVER

MOTOR TEST in

this Section.

Go to following

chart PBR TEST in

this Section.

8• With TECH 2 still

connected, select Body

/ Electronic Climate

Control / Miscellaneous

Tests / Drivers S ide A ir

Mix Motor- Door

Movement and increase

to maximum then

decrease to minimum.

• Is DTC-21 set as a

current DTC?.

Go to Step 3. Re-calibration of

Air mix door may

have corrected

fault or DTC 21 is

intermittent.

(Carry out air mix

door calibration if

not already done

so, refer to 1.2

TECH 2 TEST

MODES AND

DISPLAYS FOR

ECC DIAGNOSIS

and/or refer to

INTERMITTEN T in

this section.

DRIVER MOTOR TEST

STEP ACTION VALUE YES NO

1• Disconnect ECC wiring

harness connector

YB89.

• Connect TECH 2 to

DLC.

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to Drivers Air Mix

Door Feedback.

• Does Tech 2 display

Drivers Air Mix Door

Feedback above the

specified value?

3.4 Volts Go to step 2. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

2• With ECC connector

YB89 disconnected,

measure the resistance

between harness

terminals 1 & 2 (circuits

184 & 186) on

connector YB89.

• Is resistance less than

specified value ?

80 Ohms Go to Step 3. Go to step 8.

3• In step 2, was

resistance less than

specified value between

terminals 1 & 2 (circuits

184 & 186) on

connector YB89?

70 Ohms Go to step 7. Go to Step 4.

4• With ECC connector

YB89 disconnected,

measure the resistance

between terminal 1

(circuit 186) on

connector YB89 and

chassis ground.

• Does the meter indicate

a short to ground ?

NOTE: (Any resistance

measured here qualifies

as a short)

Ohms Repair short in

circuit 186.

Recheck and verify

repair.

Go to Step 4.

5• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 1 &

15 (circuits 186 & 62) on

connector YB89.

• Does the meter indicate

a short?

NOTE: (Any resistance

measured here qualifies

as a short)

Ohms Repair short in

circuits 186 and/or

62. Recheck and

verify repair.

Go to Step 5.

STEP ACTION VALUE YES NO

6• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 1 & 5

(circuits 186 & 367) on

connector YB89.

• Does the meter indicate

a short?

NOTE: (Any resistance

measured here qualifies

as a short)

Ohms Repair short in

circuits 186 and/or

367. Recheck and

verify repair.

Go to Step 10.

7• Disconnect drivers air

mix door motor

connector YB94.

• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 1 & 2

(circuits 184 & 186) on

connector YB89.

• Does the meter indicate

a short ?

NOTE: (Any resistance

measured here qualifies

as a short)

Ohms Repair short in

circuits 184 and/or

186. Recheck and

verify repair.

Replace drivers air

mix door motor,

refer to Section

2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

8• Inspect wiring harness

connectors YB89 and

YB94 for an intermittent

or loose terminal.

• Are connectors okay?

Go to Step 9. Repair connectors

as necessary.

Recheck and verify

repair.

9• Check for open in

circuits 184 & 186.

• Was an open or faulty

connection found?

Repair circuits 184

and/or 186.

Recheck and verify

repair.

Replace air mix

door motor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

STEP ACTION VALUE YES NO

10 • Inspect wiring harness

connectors YB89 and

YB94 for an intermittent

or loose terminal, or for

terminals shorted

together.

• Are connectors okay?

Go to Step 11. Repair connectors

as necessary.

Recheck and verify

repair.

11 • Has the DRIVER PBR

TEST been performed ? Go to Step 12 Go to following

chart PBR TEST in

this Section.

12 • Remove drivers air mix

motor assembly, refer to

Section 2E AIR

CONDITIONING - ECC

- REMOVAL &

INSTALLATION.

• Move Air mix door by

hand

• Is door physically

jammed or broken

Repair air mix door

as necessary.

Recheck and verify

repair.

Go to 13.

13 • Replace air mix motor

assembly, refer to

Section 2E AIR

CONDITIONING - ECC

- REMOVAL &

INSTALLATION.

• Did new Motor fix the

problem ?

System okay. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

DRIVER PBR TEST

STEP ACTION VALUE YES NO

1• Disconnect ECC wiring

harness connector

YB89.

• Connect TECH 2 to

DLC.

• Select Body / Electronic

Climate Control / Data

Display / Data List and

scroll to Drivers Air Mix

Door Feedback.

• Does Tech 2 display

Drivers Air Mix Door

Feedback above the

specified value?

3.4 Volts Go to step 2. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

2• Re-connect drivers air

mix motor (if

disconnected from

Motor Testing).

• With ECC connector

YB89 disconnected,

measure the resistance

between terminal 11

(circuit 188) on

connector YB89 and

chassis ground.

• Does the meter indicate

a short to ground ?

NOTE: (Any resistance

measured here qualifies as

a short).

Ohms Repair short in

circuit 188.

Recheck and verify

repair.

Go to Step 3.

3• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 1 &

11 (circuits 186 & 188)

on connector YB89.

• Does the meter indicate

a short ?

NOTE: (Any resistance

measured here qualifies as

a short).

Ohms Repair short in

circuit 186 and/or

188. Recheck and

verify repair.

Go to Step 4.

4• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 5 &

11 (circuits 367 & 188)

on connector YB89.

• Does the meter indicate

a short ?

NOTE: (Any resistance

measured here qualifies as

a short).

Ohms Repair short in

circuit 367 and/or

188. Recheck and

verify repair.

Go to Step 5.

STEP ACTION VALUE YES NO

5• Disconnect passengers

air mix motor connector

YB94 (if fitted).

• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 11 &

15 (circuits 188 & 62) on

connector YB89.

• Is resistance less than

specified values ?

<12K

Ohms Go to Step 6. Go to Step 14.

6• In Step 5, was the

measured resistance at

terminals 11 & 15

(circuits 62 & 188)

above the specified

value?

>8K

Ohms Go to Step 7. Go to Step 11.

7• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 11 &

18 (circuits 188 & 187)

on connector YB89

• Is resistance less than

specified value?

<8.5K

Ohms Go to Step 8. Go to Step 14.

8• In Step 7, was the

measured resistance at

terminals 11 & 18

(circuits 187 & 188)

above the specified

value?

>1.5K

Ohms Go to Step 9. Go to Step 11.

9• Inspect ECC wiring

harness connector

YB89 or air mix motor

connector YB94 for an

intermittent or loose

terminal.

• Are connectors okay?

Repair connectors

as necessary.

Recheck and verify

repair.

Go to Step10.

10 • Re-connect ECC

connectors YB89 &

YB87 to ECC control

module.

• Disconnect drivers air

mix motor connector

YB94.

• Turn ignition ON

• Measure voltage at

driver’s air mix motor

connector YB94

between circuits 62

(Tan wire) & 188 (White

wire).

• Is the voltage as

specified?

3.4 volts

to 3.8

volts

Go to Step 16. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

STEP ACTION VALUE YES NO

11 • Disconnect air mix

motor connectors YB94

(both if fitted).

• With ECC connector

YB89 disconnected,

measure the resistance

between terminals 11 &

15 (circuits 188 & 62 )

on connector YB89.

• Does the meter indicate

a short ?

NOTE: (Any resistance

measured here qualifies as

a short).

Ohms Repair short in

circuit 62 and/or

188. Recheck and

verify repair.

Go to Step 12.

12 • With ECC connectors

YB89 and YB94

disconnected, measure

the resistance between

terminals 15 & 18

(circuits 62 & 187) on

connector YB89.

• Does the meter indicate

a short ?

NOTE: (Any resistance

measured here qualifies as

a short).

Ohms Repair short in

circuit 62 and/or

187. Recheck and

verify repair.

Go to step 13.

13 • With ECC connectors

YB89 and YB94

disconnected, measure

the resistance between

terminals 11 & 18

(circuits 188 & 187) on

connector YB89.

• Does the meter indicate

a short ?

NOTE: (Any resistance

measured here qualifies as

a short).

Ohms Repair short in

circuit 187 and/or

188. Recheck and

verify repair.

Replace air mix

door motor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

14 • Inspect wiring harness

connectors YB89 and

YB94 for an intermittent

or loose terminal.

• Are connectors okay?

Go to Step 15 Repair connectors

as necessary.

Recheck and verify

repair.

STEP ACTION VALUE YES NO

15 • Check for open in

circuits 62, 187 & 188.

• Was an open or faulty

connection found?

Repair circuits as

necessary.

Recheck and verify

repair.

Replace air mix

door motor, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

16 • Has the DRIVER

MOTOR TEST been

performed ?

Go to Step 17. Go to previous

chart DRIVERS

MOTOR TEST in

this Section.

17 • Remove drivers air mix

motor assembly, refer to

Section 2E AIR

CONDITIONING - ECC

- REMOVAL &

INSTALLATION.

• Move Air mix door by

hand

• Is door physically

jammed or broken

Repair air mix door

as necessary.

Recheck and verify

repair.

Go to Step 18.

18 • Replace air mix motor

assembly, refer to

Section 2E AIR

CONDITIONING - ECC

- REMOVAL &

INSTALLATION.

• Did new Motor fix the

problem ?

System okay. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC - REMOVAL

& INSTALLATION.

DTC 24 - AIR MIX MOTOR PASSENGER SIDE (DZ)

Figure 2F-34

CIRCUIT DESCRIPTION:

The air m ix motor is actually an electric m otor used

to operate the air m ixing door. T he electr ic m otor is

sent a voltage signal of 12.5 volts from the ECC

control module which causes the motor to turn,

which moves the air mix door towards or away

from the heater core, the direction change takes

place by reversing the polarity of this motor.

A potentiometer (PBR) is housed in the air mix

motor circuit which feeds signals (3.6 ± 0.18 volts)

back to the ECC control module as to the

positioning of the motor and consequently the air

mix door.

DTC 24 will set: if the passenger’s PBR feedback

signal fails to reach the requested value. This will

occur if the PBR or motor is open or shor t c irc uited,

or it the air mix door is jammed or sticking.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. This test checks that the DTC is current.

3. This test checks if the motor is moving

4. This test checks that the m otor is stopping within

the correct range @ full cold.

5. This test checks that the m otor is stopping within

the correct range @ full hot.

6. Attempts to re-calibrate & check DTC is still

current

7. Determines if a if a m otor fault is m ore likely the

a PBR fault to be the cause of the fault.

8. Checks fault has been rectified.

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

DIAGNOSTIC AIDS:

An air mix motor or door problem will always be

associated with non-regulated or incorrect

temperatures from mode positions.

The ECC control module, during calibration, sets a

minimum and a maximum PBR value for the air mix

motor in it’s memory. It is these values which

determine the operating range of the air mix motor

and against which all movements of the air mix

adjustm ent are scaled. Any PBR signal value outside

the minimum or maximum vale are considered a

motor fault.

The ECC c ontrol module m onitors the rate of change

of PBR signal during air mix motor movement. If this

rate of change falls to 0 (such as a broken air mix

motor wire or physical jam b), the ECC contr ol m odule

will recognise the stoppage and set the fault code.

If DTC 24 was present before turning the ignition off,

when the ignition is turned on again, the ECC control

m odule will autom atically try to re-c alibrate the air m ix

door. This takes approxim ately 15 seconds. If the re-

calibration fails, then DTC 24 will be set again.

DTC 24 - AIR MIX MOTOR PASSENGER’S SIDE

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Turn ignition OFF.

• Connect TECH 2 to

DLC.

• Turn ignition ON when

instructed by TECH 2.

• Select Body /

Electronic Climate

Control / Diagnostic

Trouble Codes / Read

Current DTC

Information.

• Is DTC 24 displayed as

a current DTC?

Go to Step 3. Go to Step 8.

3• With TECH 2 still

connected, select Body

/ Electronic Climate

Control /

Miscellaneous Tests /

Passenger Side Air

Mix Motor - Door

Movement and

increase to maximum

then decrease to

minimum.

• Does the Passenger

Air Mix Door feedback

(voltage) on TECH 2

change?

Go to Step 4. Go to Step 7.

4• With Passengers Side

Air Mix Motor - Door

Movement test still

selected, decrease air

mix door to minimum.

• Does Tech 2 display

Drivers Air Mix Door

feedback within the

specified range?

0.6 to

0.9 Volts Go to Step 5. Go to following

chart

PASSENGER

MOTOR TEST in

this Section.

STEP ACTION VALUE YES NO

5• With Passengers Side

Air Mix Motor - Door

Movement test still

selected increase air

mix door to maximum.

• Does Tech 2 display

Passengers Air Mix

Door feedback within

the specified range?

2.6 to

2.9 Volts Go to Step 6. Go to following

chart

PASSENGER

MOTOR TEST in

this Section.

6• With TECH 2 still

connected, select Body

/ Electronic Climate

Control / Program /

Calibrate Air Mix Door

and reprogram air mix

doors.

• Turn ignition OFF.

• Turn ignition ON.

• Is DTC-24 set as a

current DTC?.

Go to following

chart

PASSENGER

MOTOR TEST in

this Section.

Go to Step 8.

7. • In Step 3, did TECH 2

display Passengers Air

mix door feedback

within the specified

range?

0.3 to

3.4 volts Go to following

chart

PASSENGER

MOTOR TEST in

this Section.

Go to following

chart

PASSENGER

PBR TEST in this

Section.

8• With TECH 2 still

connected, select Body

/ Electronic Climate

Control /

Miscellaneous Tests /

Passengers Side Air

Mix Motor- Door

Movement and

increase to maximum

then decrease to

minimum.

• Is DTC-24 set as a

current DTC?.

Go to Step 3. Re-calibration of

Air mix door may

have corrected

fault or DTC 24 is

intermittent.

(Carry out air mix

door calibration if

not already done

so, refer to 1.2

TECH 2 TEST

MODES AND

DISPLAYS FOR

ECC DIAGNOSIS

and/or refer to

INTERMITTENT

in this section.

PASSENGER’S MOTOR TEST

STEP ACTION VALUE YES NO

1• Disconnect ECC wiring

harness connector

YB89.

• Connect TECH 2 to

DLC.

• Select Body /

Electronic Climate

Control / Data Display /

Data List and scroll to

Passengers Air Mix

Door Feedback.

• Does Tech 2 display

Passengers Air Mix

Door Feedback above

the specified value?

3.4 Volts Go to step 2. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

2• With ECC connector

YB89 disconnected,

measure the

resistance between

harness terminals 3 &

4 (circuits 223 & 224)

on connector YB89.

• Is resistance less than

specified value ?

Ohms Go to Step 3. Go to step 8.

3• In step 2, was

resistance less than

specified value

between terminals 3 &

4 (circuits 223 & 224)

on connector YB89?

Ohms Go to step 7. Go to Step 4.

4• With ECC connector

YB89 disconnected,

measure the

resistance between

terminal 3 (circuit 224)

on connector YB89

and chassis ground.

• Does the meter

indicate a short to

ground ?

NOTE: (Any resistance

measured here

qualifies as a short)

Ohms Repair short in

circuit 186.

Recheck and

verify repair.

Go to Step 4.

5• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 3 & 15

(circuits 224 & 62) on

connector YB89.

• Does the meter

indicate a short?

NOTE: (Any resistance

measured here

qualifies as a short)

Ohms Repair short in

circuits 186 and/or

62. Recheck and

verify repair.

Go to Step 5.

STEP ACTION VALUE YES NO

6• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 3 & 5

(circuits 224 & 367) on

connector YB89.

• Does the meter

indicate a short?

NOTE:(Any resistance

measured here

qualifies as a short)

Ohms Repair short in

circuits 186 and/or

367. Recheck and

verify repair.

Go to Step 10.

7• Disconnect passenger

air mix door motor

connector YB94.

• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 3 & 4

(circuits 224 & 223) on

connector YB89.

• Does the meter

indicate a short ?

NOTE: (Any resistance

measured here

qualifies as a short)

Ohms Repair short in

circuits 184 and/or

186. Recheck and

verify repair.

Replace

passenger air mix

door motor, refer

to Section 2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

8• Inspect wiring harness

connectors YB89 and

YB94 for an

intermittent or loose

terminal.

• Are connectors okay?

Go to Step 9. Repair connectors

as necessary.

Recheck and

verify repair.

9• Check for open in

circuits 223 & 224.

• Was an open or faulty

connection found?

Repair circuits

184 and/or 186.

Recheck and

verify repair.

Replace air mix

door motor, refer

to Section 2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

STEP ACTION VALUE YES NO

10 • Inspect wiring harness

connectors YB89 and

YB94 for an

intermittent or loose

terminal, or for

terminals shorted

together.

• Are connectors okay?

Go to Step 11. Repair connectors

as necessary.

Recheck and

verify repair.

11 • Has the PASSENGER

PBR TEST been

performed ?

Go to Step 12 Go to following

chart PBR TEST

in this Section.

12 • Remove passenger’s

air mix motor

assembly, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL &

INSTALLATION.

• Move Air mix door by

hand

• Is door physically

jammed or broken

Repair air mix

door as

necessary.

Recheck and

verify repair.

Go to 13.

13 • Replace air mix motor

assembly, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL &

INSTALLATION.

• Did new Motor fix the

problem ?

System okay. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

PASSENGER’S PBR TEST

STEP ACTION VALUE YES NO

1• Disconnect ECC wiring

harness connector

YB89.

• Connect TECH 2 to

DLC.

• Select Body /

Electronic Climate

Control / Data Display /

Data List and scroll to

Passengers Air Mix

Door Feedback.

• Does Tech 2 display

Air Mix Door Feedback

above the specified

value?

3.4 Volts Go to step 2. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

2• Re-connect drivers air

mix motor (if

disconnected from

Motor Testing).

• With ECC connector

YB89 disconnected,

measure the

resistance between

terminal 11 (circuit

188) on connector

YB89 and chassis

ground.

• Does the meter

indicate a short to

ground ?

NOTE: (Any resistance

measured here qualifies

as a short).

Ohms Repair short in

circuit 188.

Recheck and

verify repair.

Go to Step 3.

3• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 1 & 3

(circuits 186 & 224) on

connector YB89.

• Does the meter

indicate a short ?

NOTE: (Any resistance

measured here qualifies

as a short).

Ohms Repair short in

circuit 186 and/or

188. Recheck and

verify repair.

Go to Step 4.

4• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 5 & 11

(circuits 367 & 188) on

connector YB89.

• Does the meter

indicate a short ?

NOTE: (Any resistance

measured here qualifies

as a short).

Ohms Repair short in

circuit 367 and/or

188. Recheck and

verify repair.

Go to Step 5.

STEP ACTION VALUE YES NO

5• Disconnect

passengers air mix

motor connector YB94.

• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 11 & 15

(circuits 188 & 62) on

connector YB89.

• Is resistance less than

specified values ?

<12K

Ohms Go to Step 6. Go to Step 14.

6• In Step 5, was the

measured resistance

at terminals 11 & 15

(circuits 62 & 188)

above the specified

value?

>8K

Ohms Go to Step 7. Go to Step 11.

7• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 11 & 17

(circuits 188 & 222) on

connector YB89

• Is resistance less than

specified value?

<8.5K

Ohms Go to Step 8. Go to Step 14.

8• In Step 7, was the

measured resistance

at terminals 11 & 17

(circuits 222 & 188)

above the specified

value?

>1.5K

Ohms Go to Step 9. Go to Step 11.

9• Inspect ECC wiring

harness connector

YB89 or air mix motor

connector YB94 for an

intermittent or loose

terminal.

• Are connectors okay?

Repair connectors

as necessary.

Recheck and

verify repair.

Go to Step10.

10 • Re-connect ECC

connectors YB89 &

YB87 to ECC control

module.

• Disconnect drivers air

mix motor connector

YB94.

• Turn ignition ON

• Measure voltage at

driver’s air mix motor

connector YB94

between circuits 62

(Tan wire) & 188

(White wire).

• Is the voltage as

specified?

3.4 volts

to 3.8

volts

Go to Step 16. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

STEP ACTION VALUE YES NO

11 • Disconnect air mix

motor connectors

YB94 (both if fitted).

• With ECC connector

YB89 disconnected,

measure the

resistance between

terminals 11 & 15

(circuits 188 & 62 ) on

connector YB89.

• Does the meter

indicate a short ?

NOTE: (Any resistance

measured here qualifies

as a short).

Ohms Repair short in

circuit 62 and/or

188. Recheck and

verify repair.

Go to Step 12.

12 • With ECC connectors

YB89 and YB94

disconnected,

measure the

resistance between

terminals 15 & 17

(circuits 62 & 222) on

connector YB89.

• Does the meter

indicate a short ?

NOTE: (Any resistance

measured here qualifies

as a short).

Ohms Repair short in

circuit 62 and/or

187. Recheck and

verify repair.

Go to step 13.

13 • With ECC connectors

YB89 and YB94

disconnected,

measure the

resistance between

terminals 11 & 17

(circuits 188 & 222) on

connector YB89.

• Does the meter

indicate a short ?

NOTE: (Any resistance

measured here qualifies

as a short).

Ohms Repair short in

circuit 187 and/or

188. Recheck and

verify repair.

Replace air mix

door motor, refer

to Section 2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

STEP ACTION VALUE YES NO

14 • Inspect wiring harness

connectors YB89 and

YB94 for an

intermittent or loose

terminal.

• Are connectors okay?

Go to Step 15 Repair connectors

as necessary.

Recheck and

verify repair.

15 • Check for open in

circuits 62, 222 & 188.

• Was an open or faulty

connection found?

Repair circuits as

necessary.

Recheck and

verify repair.

Replace air mix

door motor, refer

to Section 2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

16 • Has the

PASSENGER’S

MOTOR TEST been

performed ?

Go to Step 17. Go to previous

chart

PASSENGER’S

MOTOR TEST

in this Section.

17 • Remove passenger’s

air mix motor

assembly, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL &

INSTALLATION.

• Move Air mix door by

hand

• Is door physically

jammed or broken

Repair air mix

door as

necessary.

Recheck and

verify repair.

Go to Step 18.

18 • Replace air mix motor

assembly, refer to

Section 2E AIR

CONDITIONING -

ECC - REMOVAL &

INSTALLATION.

• Did new Motor fix the

problem ?

System okay. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

DTC 36 - SERIAL DATA COMMUNICATIONS ERROR

Figure 2F-41

CIRCUIT DESCRIPTION:

When investigating any complaint of an ECC

problem or malfunction, always begin diagnosis

with the following diagnostic circuit check. This

check is a preliminary procedure that checks to

ensure the SDM is communicating on the serial

data line as well as helping to identify a problem or

malfunction and directing the reader to the

appropriate diagnostic chart in this section.

With TECH 2 connected to the DLC and ignition

switched on, TECH 2 should display serial data

communication.

If TECH 2 does not display serial data, the serial

data circuit maybe open or shorted.

There are several other control modules that are

connected to the serial data line (PCM, BCM,

ABS/ASR, instruments and SDM. Any of these

control modules could cause a fault on the serial

data line. This fault could result in TECH 2 not

being able to display serial data.

DTC will set if set if the serial data line (circuits

1220 or 1221) are interrupted and the ECC does

not receive data from the PCM or BCM for 10

seconds.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart

1. Ensures the Diagnostic Circuit Check has been

performed.

2. Determines if there is a fault in the serial data

circuit (1221) between the BCM and PCM by

starting the engine. If serial data was lost while

the engine was running, the engine will restart

but there will be a one second delay.

3. Checks if fault is common with other control

modules connected to the serial data circuit.

4. Checks internal switch in BCM for open circuit.

5. Checks circuit 1220 and determines if fault is in

wiring or a control module.

6. Checks circuit 1220 for open circuit.

7. Checks integrity of earth circuits for the BCM,

PCM and ECC control module

DIAGNOSTIC AIDS:

A fault with the serial data circ uit could be caused by

one or more of the several control modules

connected to this serial data circuit. Isolate the fault

by disconnecting each control module, one at a time

until serial data communication is restored.

NOTES ON DIAGNOSTIC CHART:

1. Refer to Section 12P WIRING DIAGRAMS for

procedures on checking wiring faults.

2. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

3. To check the integrity of the ECC control module

earth circuit; turn ignition and ECC system ON

and check for a voltage drop across circuit 155

(Black/Yellow wire), between ECC control

module connector YB87, terminal 2, and earth

point E3.

To check the integrity of the BCM earth circuit;

turn ignition ON and check for a voltage drop

across circuit 155 (Black/Yellow wire), between

BCM connector YB176, terminal A1 and earth

point E3

To check the integrity of the PCM earth circuit,

refer to Earth Credibility Check in Section 6C1

POWERTRAIN MANAGEMENT - V6 ENGINE

or Section 6C2 POWERTRAIN

MANAGEMENT - V8 ENGINE.

STEP ACTION VALUE YES NO

1• Was the Diagnostic

Circuit Check

performed?

Go to Step 2. Go to Chart A -

DIAGNOSTIC

CIRCUIT CHECK

in this Section.

2• Connect TECH 2 to

the DLC.

• Select Body / DTC

Check / DTC Check.

• Can TECH 2

communicate with the

BCM and PCM?

NOTE: If “No Data” is

displayed next to the BCM

or PCM, then there is no

communication between

TECH and these control

modules.

Go to Step 3. Go to BCM

Serial Data

Communication

diagnostics in

Section 12J-2

HIGH SERIES

BCM.

3• In Step 2, was TECH

able to communicate

with all the other

control modules,

except the ECC control

module, fitted to the

vehicle (ABS,

instruments, SRS)?

NOTE: If “No Data” is

displayed next to a control

module, then there is no

communication between

TECH and that control

module.

Go to Step 6. Go to Step 4.

4• Using an ohmmeter,

check continuity of

circuits 1220

(Green/White wire)

and 1221 (Red/Black

wire) between BCM

connector YB175,

terminals 2 and 9

(refer NOTE 1).

• Does continuity exist?

Go to Step 5. Replace BCM,

refer to Section

12J-2 HIGH

SERIES BCM.

STEP ACTION VALUE YES NO

5• Check circuit 1220 for

open, short to earth or

short to voltage

between BCM and

individual control

modules (refer

NOTE 1).

• Is circuit 1220 okay?

NOTE: Disconnect each

control module in circuit

1220 one at a time to

isolate the fault in the

circuit or to identify the

control module causing

the fault.

Replace faulty

control module as

necessary, refer

to relevant

Section. Recheck

and verify repair.

Repair circuit

1220 as

necessary.

Recheck and

verify repair.

6• Using an ohmmeter,

check for continuity

between BCM

connector YB175,

terminal 9 and ECC

control module

connector YB87,

terminal 6

(Green/White wire)

(refer NOTE 1).

• Does continuity exist?

•

Go to Step 7. Repair open in

circuit 1220.

Recheck and

verify repair.

7• Check the integrity of

the ECC control

module, BCM and

PCM earth circuits by

performing a voltage

drop on each circuit

(refer NOTE 3)

• Are voltage less than

the specified value?

0.15

Volts Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

Repair earth

circuit as

necessary.

Recheck and

verify repair

DTC 37 - ECC CONTROL MODULE - INTERNAL FAILURE

Figure 2F-42

CIRCUIT DESCRIPTION:

When this diagnostic trouble code (DTC) is set, it indicates a failure attributed to the processor within the ECC

Module itself.

If DTC 37 sets, replace the ECC control module. Refer to Section 2E-2 AIR CONDITIONING - ECC - REMOVAL

AND INSTALLATION.

DTC 38 - EEPROM CHECKSUM FAILURE

Figure 2F-43

CIRCUIT DESCRIPTION:

The EEPROM (expandable, erasable program,

read only, memory) is part of the PCB (Printed

Circuit Board) housed within the ECC Module.

The function of the EEPROM is to store data used

to control operating parameters of the ECC

system.

When this DTC is set, it indicates that the

EEPROM has been corrupted or has altered.

DTC 38 will set: if the ECC system calibration is

corrupted or the EEPROM in the ECC control

module fails.

TEST DESCRIPTION:

Number(s) below refer to step numbers in the

following Diagnostic Chart.

1. Determines if ECC control module is faulty by

re-programming the ECC control module.

2. Determines if ECC control module is faulty.

NOTES ON DIAGNOSTIC CHART:

1. Refer to 1.1 TECH 2 DIAGNOSTICS in this

Section for connecting and using TECH 2.

DIAGNOSTIC AIDS:

If the ECC system programming is corrupted, re-

calibration can be carried out via TECH 2. To

calibrate the system refer to 1.2 TECH 2 TEST

MODES AND SCREEN DISPLAYS in this Section.

STEP ACTION VALUE YES NO

1• Reprogram ECC

control module Code

Version using TECH 2,

refer 1.2 TECH 2

TEST MODES AND

SCREEN DISPLAYS

FOR ECC

DIAGNOSIS in this

Section.

• Was programming

successful?

NOTE: If programming is

unsuccessful, repeat the

program at least twice, as

the system may have

crashed during this

process.

Go to Step 2. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.

2• Connect TECH 2 to

DLC (refer NOTE 1

above).

• Select Body /

Electronic Control

Module / Diagnostic

Trouble Codes / Clear

DTC Information and

clear DTC’s.

• Were all DTC’s

cleared?

System okay. Replace ECC

control module,

refer to Section

2E AIR

CONDITIONING -

ECC -

REMOVAL &

INSTALLATION.