SECTION 6C2-2B - SYMPTOMS –

V6 SUPERCHARGED ENGINE

IMPORTANT

Before p erf orming any Service O p eratio n o r ot her p roced ure describ ed in t his Sect ion , refer t o Sect ion 00

CAUTIONS AND NOTES for correct workshop practices with regard to safety and/or property damage.

W hen no diagnostic trouble codes have been set and the Tec h 2 data values are within typical ranges, you should

diagnose the condition based on the symptoms of the complaint.

This Symptom Section starts with preliminary checks that must be performed in order to diagnose by symptom.

Then, intermittent conditions are discussed. These preliminary pages provide important information to assist you

with symptom diagnosis. Next, the contents of this Section presents the various symptoms and lists a series of

checks for each.

Many of the s ymptom diagnostic s st art with a very important pr ocedur e, a vis ual/physical inspection. Always look for

the obvious first. Some situations may warrant observing the driver. Is the driver using the correct shift lever position

or riding the brake pedal? Visually check the engine, transmission and PCM connectors. Are there any

disconnected wires or incorrectly installed components? Finally, are there obvious signs that someone may have

performed incorrect repairs? These check s take very little time; they can eliminate the time spent on a broad-base

systematic diagnos is by direct ing you to the problem . If they do not reveal the problem , proceed to chec k the other

suspect systems, as shown.

The last pages of this Sec tion contain PCM connector symptom Tables. If you are diagnosing a problem , scan the

right-most column for the symptom(s) and check for the correct wire and voltage at the designated connector cavity.

CONTENTS

PCM AND PROM

IMPORTANT PRELIMINARY CHECKS

BEFORE USING THIS SECTION

SYMPTOM

VISUAL/PHYSICAL CHECK

INTERMITTENTS

HARD START

PRELIMINARY CHECKS

SENSORS

IGNITION SYSTEM

FUEL SYSTEM

ADDITIONAL CHECKS

SURGES AND/OR CHUGGLES

PRELIMINARY CHECKS

SENSOR CHECKS

IGNITION SYSTEM CHECKS

FUEL SYSTEM CHECKS

ADDITIONAL CHECKS

LACK OF POWER, SLUGGISH OR SPONGY

PRELIMINARY CHECKS

SENSOR CHECKS

ENGINE MECHANICAL CHECKS

IGNITION SYSTEM CHECKS

FUEL SYSTEM CHECKS

ADDITIONAL CHECKS

DETONATION/SPARK KNOCK

PRELIMINARY CHECKS

IGNITION SYSTEM CHECKS

ENGINE MECHANICAL CHECKS

COOLING SYSTEM CHECKS

FUEL SYSTEM CHECKS

ADDITIONAL CHECKS

HESITATION, SAG, STUMBLE

PRELIMINARY CHECKS

SENSOR CHECKS

IGNITION SYSTEM CHECKS

FUEL SYSTEM CHECKS

ADDITIONAL CHECKS

CUTS OUT, MISSES

PRELIMINARY CHECKS

IGNITION SYSTEM CHECKS

ENGINE MECHANICAL CHECKS

FUEL SYSTEM CHECKS

ADDITIONAL CHECKS

ROUGH, UNSTABLE, OR INCORRECT IDLE, STALLING

PRELIMINARY CHECKS

ENGINE MECHANICAL CHECKS

FUEL SYSTEM CHECKS

ADDITIONAL CHECKS

POOR FUEL ECONOMY

PRELIMINARY CHECKS

IGNITION SYSTEM CHECKS

COOLING SYSTEM CHECKS

ENGINE MECHANICAL CHECKS

ADDITIONAL CHECKS

FUEL SYSTEM CHECKS

BACKFIRE

PRELIMINARY CHECKS

IGNITION SYSTEM CHECKS

ENGINE MECHANICAL CHECKS

FUEL SYSTEM CHECKS

EXCESSIVE EXHAUST EMISSIONS OR ODOURS

PRELIMINARY CHECKS

IGNITION SYSTEM CHECKS

COOLING SYSTEM CHECKS

FUEL SYSTEM CHECKS

ADDITIONAL CHECKS

DIESELING, RUN-ON

PRELIMINARY CHECKS

FUEL SYSTEM CHECKS

IGNITION SYSTEM CHECKS

RICH/LEAN SYMPTOM CHART

CIRCUIT DESCRIPTION

TEST DESCRIPTION

DIAGNOSTIC AIDS

RICH/LEAN SYMPTOM CHART

AUTOMATIC TRANSMISSION SYMPTOM TABLES

OIL PRESSURE HIGH OR LOW

HARSH SHIFTS / INACCURATE SHIFT POINTS

1ST GEAR RANGE ONLY – NO UPSHIFTS

SLIPS IN 1ST GEAR

SLIPPING OR ROUGH 1–2 SHIFT

NO 2-3 SHIFT OR 2-3 SHIFT SLIPS, ROUGH

OR HUNTING

2ND/3RD GEARS ONLY OR 1ST/4TH

GEARS ONLY

THIRD GEAR ONLY

3-2 FLARE OR TIE-UP

NO 3-4 SHIFT, SLIPS OR ROUGH 3-4 SHIFT

NO REVERSE OR SLIPS IN REVERSE

NO PART THROTTLE OR DELAYED

DOWNSHIFTS

HARSH GARAGE SHIFT

NO OVERRUN BRAKING - MANUAL 3-2 - 1

NO TCC APPLY

TORQUE CONVERTER CLUTCH SHUDDER

NO TCC RELEASE

DRIVES IN NEUTRAL

2ND GEAR START (DRIVE RANGE)

NO PARK

RATCHETING NOISE

FLUID OUT THE VENT

VIBRATION IN REVERSE AND WHINING

NOISE IN PARK

NO DRIVE IN ALL RANGES

NO DRIVE IN DRIVE RANGE

FRONT OIL LEAK

DELAY IN DRIVE AND REVERSE

PCM CONNECTOR SYMPTOM TABLES

TESTING GROUNDS

BASICS

GROUND CIRCUITS

PARALLEL GROUNDS

CHECKING GROUNDS

SOLID STATE CIRCUIT VOLTAGE DROP

SPECIFICATIONS

GROUND CREDIBILITY CHECK

CIRCUIT DESCRIPTION

TEST DESCRIPTION

DIAGNOSTIC AIDS

CORRECTING PROBLEMS IN GROUND

CIRCUITS

PCM AND PROM

Since the PCM can have a failure which may affect only one circuit, following the Diagnostic Procedures in this

section will determine which circuit has a problem and where it is.

If a diagnostic T able indicates that the PCM connections or PCM is the cause of a problem, and the PCM is

replaced, but does not correct the problem, one of the following may be the reason:

• There is a problem with the PCM terminal connections. The diagnostic Table will say "PCM connections or

PCM." The terminals may have to be removed from the connector in order to check them properly.

• The PCM or PROM is not correct for the application. The incorrect PCM or PROM may cause a malfunction

and may or may not set a code.

• The problem is intermittent. This means that the problem is not present at the time the system is being

checked. In this c as e, ref er to the "Symptoms" Tables and m ake a carefu l phys ical inspec tion of all com ponents

of the system involved.

• Shorted solenoid, relay coil, or harness. Solenoids and relays are turned "ON" and "OFF" by the PCM, using

internal electronic switches called "Drivers." Each "driver" is part of a group of four (called "Quad drivers").

Failure of one driver may cause other drivers in the set to m alfunction. Solenoid and relay coil resis tance must

measure more than 20 ohms, in most cases. Less resistance may cause early failure of the PCM "driver."

Before r eplacing a PCM, be sure to c heck the c oil resistance of all solenoids and re lays controlled by the PCM.

See PCM wiring diagram for the solenoid(s) and relay(s) and the coil terminal identification.

• The PROM m ay be faulty. Although these rar ely fail, they operate as par t of the PCM. T heref ore, it could be the

cause of the problem. Substitute a known good PROM.

• The replacement PCM may be faulty. After the PCM is replaced, the system should be rechecked for proper

operation. If the diagnostic Table again indicates the PCM is the problem, substitute a known good PCM.

Although this is an extremely rare condition, it could happen.

Figure 6C2-2B-1 – Supercharged Engine – Powertrain Wiring Harness to Engine Assembly Ground Locations.

Legend

1. Engine Ground Terminal.

2. Nut. 3. Engine Ground Terminal.

4. Bolt.

4288

IMPORTANT P RELIMINARY CHECKS

BEFORE USING THIS SECTION:

Before using this Symptoms Section you should have performed the "On Board Diagnostic System Check" as

detailed in Section 6C2-2A and determined that:

1. The "Check Powertrain" Malfunction Indicator Lamp (MIL) icon is operating correctly.

2. There are no diagnostic trouble codes stored.

3. There is a diagnostic trouble code stored in the PCM memory and the "Check Powertrain” MIL is not activated.

4. The diagnostic table for the diagnostic trouble code indicates that the trouble is intermittent.

5. You are familiar with the Powertrain wiring harness to engine assembly ground locations, illustrated in Figure

6C2-2B-1 and as described in the various "SYMPTOM TABLES" in this Section.

SYMPTOM:

Verify the customer complaint, and locate the correct symptom in the table of contents. Check all the items

indicated under that symptom.

If the “ENGINE CRANKS BUT WILL NOT RUN”, refer to Table A 3.1 in 6C2-2A DIAGNOSTIC TABLES – V6 S/C

ENGINE.

VISUAL/PHYSICAL CHECK:

Several of the symptom procedures call for a “Careful Visual/Physical Check”. The importance of this step cannot

be stressed too strongly, as it can lead to the correction of a problem without further check s, saving valuable time.

This check should include the checking of:

• Service records for any recent repairs that may indicate a related problem, or the current need for scheduled

maintenance.

• PCM sensors for being in their proper location.

• PCM ground circuits terminate at 2 separate eyelet terminals. On a V6 Supercharged engine, these attach to

the engine at two separate locations: the rear of the left cylinder head, and on the by-pass tube and drive belt

tensioner attaching s tud, below the generator (ref er Figure 6C2-2B-1). T hey must be c lean and tight. Check for

ground terminals that may be loose under the retaining nuts/bolts, or for terminals that may have been left off

after engine repair. Any repair of the wire to terminal connection m ust include soldering with resin core solder.

(NEVER use acid core solder for any wiring repairs.)

• Vacuum hoses for splits, kinks, and proper connections. Check thoroughly for any type of leak or restriction.

• Air leaks at throttle body mounting area and intake manifold sealing surfaces.

• Ignition wires for cracking, hardness, proper routing and carbon tracking.

• Wiring for proper connections, pinches and cuts.

• Check for any non genuine Holden's options or accessories that may have been fitted to the vehicle that may

cause or exaggerate the problem.

INTERMITTENTS

DEFINITION: Problem may or m ay not turn "ON" the Check Powertr ain Malfunction Indic ator Lam p (MIL) or store a

DTC. DO NOT use the Diagnostic Trouble Code (DTC) Tables for intermittent problems. When using the code

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

tables may result in replacement of good parts.

• Most inter mittent problem s are caused by faulty electrical connections or wiring. Perform car eful visual/physical

check as described at the start of this Section - "IMPORTANT PRELIMINARY CHECKS".

CHECK FOR:

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

• Improperly formed or damaged terminals. All connector terminals in the problem circuit should be carefully

reformed or replaced to insure proper contact tension.

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

outlined in service operations.

• PCM ground circuit terminals being loose at the engine. On a V6 engine these attach to the engine at two

separate locations : the rear of the lef t cylinder head, and on the by-pass tube and drive belt tensioner attaching

stud, below the generator, refer Figure 6C2-2B-1.

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

connected to a s uspec ted c irc uit. A T ec h 2 c an als o be used to help detec t inter mittent conditions . An abnor mal

voltage, or Tech 2 reading, when the problem occurs, indicates the problem m ay be in that circuit. If the wiring

and connectors check OK, and a diagnostic trouble code was stored for a circuit having a sensor, except for

DTC's 44 or 64 and 45 or 65, substitute a known good sensor and recheck.

• Loss of diagnostic code memory. To check, disconnect TP sensor and idle engine until the Check Powertrain

Malfunction Indicator Lamp (MIL) activates. DTC 22 should be stored, and kept in memory when ignition is

turned "OFF." If not, the PCM is faulty.

• With the V6 Supercharged engine m anagem ent s ystem, an interm ittent Chec k Powertr ain Malfunc tion Indicator

Lamp (MIL) with no stored diagnostic trouble code may be caused by:

– Ignition coil shorted to ground and arcing at spark plug wires or plugs.

– Interm ittent short to + 12 volts on 0 – 5 volt input, c ircuits 448 (diagnostic r equest), 410 (ECT sens or), 492

(MAF sensor), 411 (TP sensor), and 5089 (IAT sensor).

• Check for an electrical system interference caused by a defective relay, PCM 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.

• EST wires should be routed away from spark plug wires, ignition wires, ignition module assembly and

generator. The wire from PCM to ignition should have a good connection.

• Check f or an open diode, acr os s A/C c ompres s or c lutch and for other open diodes ( ref er to the wiring diagrams

with TABLE A-11.1 or TABLE A-11.3 in 6C2-2A in this Section).

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

HARD START

DEFINITION: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but

immediately dies.

PRELIMINARY CHECKS:

• Perform the careful visual/physical checks as described at the start of this Section - "IMPORTANT

PRELIMINARY CHECKS".

• Make sure the driver is using the correct starting procedure. Do not depress accelerator pedal during cranking.

• TABLE A-3.1 for V6 S/C Engine "ENGINE CRANKS BUT WILL NOT RUN" in 6C2-2A DIAGNOSTIC

CHARTS. Although this table may not exactly describe the problem, most all of the causes of a "no start" can

also cause a "hard start".

• Time or distance travelled since a normal engine tune-up has been performed, refer to time/distance intervals

specified in the MY 2003 VY and V2 Series Owner’s Handbook.

• PCM ground circuit terminals being loose at the engine. On a V6 engine these attach to the engine at two

separate locations : the rear of the lef t cylinder head, and on the by-pass tube and drive belt tensioner attaching

stud, below the generator, refer Figure 6C2-2B-1.

SENSORS:

CHECK:

• Engine Coolant Temperature (ECT) sensor using Tech 2, compare coolant temperature with ambient

temperature on cold engine.

• If coolant temper ature r eading is 5° C greater than or less than ambient air temperature on a cold engine, check

resistance in coolant sensor circuit or sensor itself. Compare ECT resistance value to the "Diagnostic Aids"

table on DTC 15 table in 6C2-2A DIAGNOSTIC CHARTS, in this Section.

• MAF sensor for a shifted sensor calibration, refer TABLE A-6.1 "MAF OUTPUT CHECK" in 6C2-2A

DIAGNOSTIC CHARTS, in this Section

• TP Sensor for binding or a high TP sensor voltage with the throttle closed.

IGNITION SYSTEM:

CHECK:

• Spark plug leads being misrouted at the coils or at the spark plugs.

• For proper ignition voltage output with spark tester, Tool No. 7230 (also released as ST-125).

• Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, incorrect gap, burned electrodes, or

heavy deposits. Repair or replace as necessary.

• Bare or shorted wires.

FUEL SYSTEM:

CHECK:

• Fuel pump relay operation; pump should turn "ON" for 2 seconds when ignition is turned "ON." Use

TABLE A-4.1 for Supercharged Engine.

• Fuel pressure, refer to TABLE A-4.3 in 6C2-2A DIAGNOSTIC CHARTS, in this Section.

• Contaminated fuel or incorrect fuel.

• If the problem occurs worse with hotter temperatures, check for leaking injectors, refer TABLE A-4.3 in 6C2-2A

DIAGNOSTIC CHARTS, in this Section.

NOTE: A faulty in-tank f uel pum p check valve will allow the fuel in the lines to drain back to the tank after engine is

stopped. To check for this condition, perform fuel system diagnosis, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC

CHARTS, in this Section.

ADDITIONAL CHECKS:

CHECK:

• Exhaust back pressure, refer TABLE A-13 "RESTRICTED EXHAUST CHECK" in 6C2-2A DIAGNOSTIC

CHARTS, in this Section.

• IAC Operation, refer to TABLE A-7.1 in 6C2-2A DIAGNOSTIC CHARTS, in this Section.

• Basic engine problem. Camshaft timing chain for being stripped or slipped, causing valve timing to be retarded.

• Compression. Remove relays ‘X4’ (engine control – EFI) and ‘X16’ (fuel pump) from the underhood electrical

centre, before performing test.

• Service Bulletins for updates.

SURGES AND/OR CHUGGLES

DEFINITION: Engine power variation under steady throttle or cruise, feels like the vehicle speeds up and slows

down with no change in the accelerator pedal.

PRELIMINARY CHECKS:

• Perform the careful visual checks as described at the start of this Section - "IMPORTANT PRELIMINARY

CHECKS".

• Make sure driver understands transmission torque converter clutch, and A/C compressor operation as

explained in the Owner’s Handbook.

• Time or distance travelled since normal engine tune-up has been performed. Refer to time/distance intervals

specified in the MY 2003 VY and V2 Series Owner’s Handbook.

SENSOR CHECKS:

• Each heated Oxygen Sensor (HO 2S) should respond quic kly to different thr ottle positions. If they do not, chec k

each Oxygen Sensor (HO2S) for silicon or other contamination from fuel, or the use of improper RTV sealant.

The sensor may have a white, powdery coating and result in a high but false signal voltage (rich exhaust

indication). The PCM will then reduce the amount of fuel delivered to the engine, causing a severe driveability

problem. Also, look for coolant additive contamination or cracking. Also check the LTFT values with Tech 2.

• MAF sensor for proper operation, refer TABLE A-6.1 “MAF OUTPUT CHECK” in 6C2-2A DIAGNOSTIC

TABLES in this Section.

IGNITION SYSTEM CHECKS:

• For proper ignition voltage output using spark tester, Tool No. 7230 (also released as ST-125).

• Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or

heavy deposits. Repair or replace as necessary. Also, check spark plug wires.

• Ignition secondary coil or wiring shorting to ground.

FUEL SYSTEM CHECKS:

• Contaminated or incorrect fuel.

NOTE: To determine if the condition is caused by a rich or lean system, the vehicle should be driven at the

speed of the c om plaint. Monitoring Long T erm F uel Tr im and Short T erm Fuel T rim values with Tech 2 will help

to identify a problem.

Lean – Long Term Fuel Trim near +25%. Refer to "Diagnostic Aids" with DTCs 44 or 64 in 6C2-2A

DIAGNOSTIC TABLES in this Section.

Rich – Long Term Fuel Trim near - 22%. Refer to "Diagnostic Aids" with DTCs 45 or 65 in 6C2-2A

DIAGNOSTIC TABLES in this Section.

• Fuel pressure while condition exists, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• In line fuel filter. Replace if dirty or plugged.

• Restricted fuel injectors. Perform an Injector Balance Test, using Tech 2 to check flow rate.

ADDITIONAL CHECKS:

• PCM ground circuits for being clean, tight and in their proper location.

• Vacuum lines for splits, kinks, leaks and proper connections.

• Generator output voltage. Repair if less than 9 or more than 16 volts.

• Speedometer reading with the speed on Tech 2 are equal.

• Service Bulletins for updates.

• Correct PROM being installed into the PCM.

• Excessive exhaust back pressure, refer TABLE A-13 "RESTRICTED EXHAUST CHECK" in 6C2-2A

DIAGNOSTIC TABLES in this Section.

• TCC operation for proper operation.

LACK OF POWER, SLUGGISH, OR SPONGY

DEFINITION: Engine delivers less than expected power. Little or no increase in speed when accelerator pedal is

pushed down part way.

PRELIMINARY CHECKS:

• Perform the careful visual/physical checks as described at the start of this Section – "IMPORTANT

PRELIMINARY CHECKS".

• Compare customer's car to similar unit. Make sure the customer has an actual problem.

• Remove air filter and check air filter for dirt, or for being plugged. Replace as necessary.

• Tim e or distanc e travelled since norm al engine tune-up has been perform ed. Refer to time/distance intervals in

MY 2003 VY and V2 Series Owner’s Handbook.

SENSOR CHECKS:

• MAF sensor for proper operation, refer TABLE A-6.1 "MAF OUTPUT CHECK" in 6C2-2A DIAGNOSTIC

TABLES in this Section.

ENGINE MECHANICAL CHECKS:

• Engine valve timing.

• Engine for correct or worn camshaft.

• Compression. Remove relays ‘X4’ (engine control – EFI) and ‘X16’ (fuel pump) from the underhood electrical

centre, before performing test.

• Check Supercharger system. Refer to functional check TABLE 2-6 for "Boost Control System Check" in 6C2-2A

DIAGNOSTIC TABLES in this Section.

IGNITION SYSTEM CHECKS:

• Secondary voltage using a shop oscilloscope or a spark tester ST-125 or 7230.

• For ignition misfire under heavy engine load. Check each spark plug lead for excessive resistance (or open

circuit), or for faulty or cracked spark plugs.

FUEL SYSTEM CHECKS:

• Restricted fuel filter, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Fuel pressure, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Contaminated fuel, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Fuel Pump Control Module check. Refer to TABLE 4.1 in 6C2-2A DIAGNOSTIC TABLES in this Section.

ADDITIONAL CHECKS:

• PCM ground circuit for being clean, tight and in their proper locations.

• Generator output voltage. Repair if less than 9 or more than 16 volts.

• Exhaust system for possible restriction, refer TABLE A-13 in 6C2-2A DIAGNOSTIC TABLES in this Section.

– Inspect exhaust system for damaged or collapsed pipes.

– Inspect muffler for heat distress or possible internal failure.

• Torque Converter Clutch (TCC) for proper operation.

DETONATION/SPARK KNOCK

DEFINITION: A mild to severe ‘ping’, usually worse under acceleration. The engine makes sharp metallic knocks

that change with throttle opening.

PRELIMINARY CHECKS:

• Perform the careful visual/physical checks as described at the start of this Section – "IMPORTANT

PRELIMINARY CHECKS".

NOTE: If Tech 2 r eadings ar e nor mal (r ef er inf ormation with "On-Board Diagnostic System Check" in 6C2-2A

DIAGNOSTIC TABLES in this Section) and there are no engine mechanical faults, fill the fuel tank with a

premium unleaded fuel and re-evaluate vehicle performance.

IGNITION SYSTEM CHECKS:

• Spark plugs for proper heat range.

ENGINE MECHANICAL CHECKS:

• Combustion chambers for excessive carbon build up. Remove carbon with top engine cleaner and follow

instructions on can. If the problem re-occurs and top engine cleaner corrects it again, look for possible causes

of high oil consumption.

• For excessive oil in the combustion chamber – Valve stem oil seals leaking.

• Combustion chamber pressure by performing a compression test. Remove relays ‘X4’ (engine control – EFI)

and ‘X16’ (fuel pump) from the underhood electrical centre, before performing test.

• For incorrect basic engine parts such as camshaft, heads, pistons, etc.

COOLING SYSTEM CHECKS:

• Check for obvious overheating problems:

– Low engine coolant.

– Defective engine thermostat.

– Loose water pump belt.

– Restricted air flow to radiator, or restricted coolant flow through radiator.

– Inoperative electric cooling fan circuit, refer to TABLE A-12.1 in 6C2-2A DIAGNOSTIC TABLES in this

Section.

– Correct coolant solution should be a 50/50 mix of antifreeze coolant and water.

FUEL SYSTEM CHECKS:

• Fuel quality and proper octane rating.

NOTE: To determine if the condition is caused by a rich or lean system, the car should be driven at the speed of

the complaint. Monitoring Long Term Fuel Trim values with Tech 2 will help identify the problem.

Lean – Long Term Fuel Trim near +25%. Refer to "Diagnostic Aids" with DTCs 44 or 64 in 6C2-2A

DIAGNOSTIC TABLES in this Section.

Rich – Long Term Fuel Trim near –22%. Refer to "Diagnostic Aids" with DTCs 45 or 65 in 6C2-2A

DIAGNOSTIC TABLES in this Section.

• Fuel Control Module operation. Refer to TABLE A-4.1 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Fuel pressure, refer to TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this Section.

ADDITIONAL CHECKS:

• Vacuum leaks.

• TCC operation (TCC applying too soon).

• For correct PROM being installed into the PCM.

• Service Bulletins for updates.

HESITATION, SAG, STUMBLE

DEFINITION: A momentary lack of response as the accelerator is pushed down. Can occur at all vehicle speeds.

Usually most sever e when fir st tr ying to mak e the c ar move, as f r om a s top sign. May cause engine to s tall if severe

enough.

PRELIMINARY CHECKS:

• Perform the careful visual/physical checks as described at the start of this Section - "IMPORTANT

PRELIMINARY CHECKS".

• Time or distance interval since normal engine tune-up has been performed. Refer to time/distance intervals

specified in Owner’s Handbook.

• Vacuum hoses for splits, kinks, and proper connections.

• For vacuum leaks at throttle body mounting and intake manifold.

SENSOR CHECKS:

• TP Sensor - Check TP Sensor for binding or sticking. Voltage should increase at a steady rate as throttle is

moved toward Wide Open Throttle (WOT), refer TABLE A-6.2 in 6C2-2A DIAGNOSTIC TABLES in this

Section.

• MAF sensor, refer to TABLE A-6.1 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Engine coolant temperature sensor resistance. Refer to DTC 14 in 6C2-2A DIAGNOSTIC TABLES in this

Section, for engine coolant temperature sensor temperature versus resistance table.

IGNITION SYSTEM CHECKS:

• Spark plugs for being fouled, or for there being faulty secondary wiring.

• Ignition system ground, circuit 453.

FUEL SYSTEM CHECKS:

• Fuel pressure, refer to TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Contaminated or incorrect fuel.

• Canister purge sy stem for proper operation.

• Fuel injectors. Perform injector balance test.

ADDITIONAL CHECKS:

• Service Bulletins for updates.

• Exhaust system back pressure, refer TABLE A-13 "RESTRICTED EXHAUST SYSTEM TEST" in 6C2-2A

DIAGNOSTIC TABLES, in this Section.

• Engine thermostat functioning correctly and proper heat range.

• Generator output voltage. Repair if less than 9 or more than 16 volts.

CUTS OUT, MISSES

DEFINITION: Steady pulsation or jerking that follows engine speed, usually more pronounced as engine load

increases. The exhaust has a steady spitting sound at idle or under load.

PRELIMINARY CHECKS:

• Perfor m the caref ul visual/phys ical checks as described at st art of this Sec tion - "IM PORTANT PRELIM INARY

CHECKS".

IGNITION SYSTEM CHECKS:

• If ignition system is suspected of causing a miss at idle or cutting out under load.

• If the previous checks did not find the problem, visually inspect ignition system for moisture, dust, cracks, burns,

etc. Spray plug wires with fine water mist to check for shorts.

• Check for a misfiring cylinder at idle by:

1. Start engine and perform a cylinder balance test, using Tech 2.

2. If there is an engine speed drop on all cylinders (equal to within 50 rpm), go to ROUGH, UNSTABLE, OR

INCORRECT IDLE, STALLING symptom, in this Section.

3. If there is no engine speed drop on one or more cylinders, or excessive variation in drop, check for spark on

the suspected c ylinder(s) with Spark Chec k ing Tool No. 7230 ( also released as ST -125). If no spark , check

plug lead for excessive resistance (or possibly ‘open'). If there is spark, remove spark plug(s) in those

cylinders and check for:

– Cracks – Wear.

– Improper Gap – Burned Electrodes.

– Heavy Deposits.

ENGINE MECHANICAL CHECKS:

• Compression. Perform compression check on questionable cylinder(s) found above. If compression is low,

repair as necessary. Remove relays ‘X4’ (engine control – EFI) and ‘X16’ (fuel pump) from the underhood

electrical centre, before performing test.

• Base engine. Remove rocker covers. Check for bent pushrods, worn rocker arms, broken valve springs, worn

camshaft lobes and valve timing, repair as necessary.

FUEL SYSTEM CHECKS:

• Fuel system – Blocked fuel filter, low pressure, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this

Section.

• Contaminated or incorrect fuel.

• Performance of injector. If there is good spark and compression on all cylinders, check for restricted or non-

operating fuel injectors. To check for a non-operating injector, perform an Injector Balance test, using Tech 2,

or:

W ith the engine idling, check for click ing sound at each injec tor with a stethoscope or long screwdriver held on

the body of each injector. If any injector fails to make the clicking sound, disconnect the electrical connector,

and connect an injector node light tester such as Tool No. J34730-2C (also released as BT-8329), across the

harness connector terminals. If the test light blinks with the engine idling, replace the injector. If there is no

blinking light, check for an "open" wire leading to that injector. Refer to Fuel Injector Circuit Diagnosis

TABLE 3.1 in 6C2-2A DIAGNOSTIC TABLES in this Section.

ADDITIONAL CHECKS:

• For EMI interference. A missing condition can be caused by Electromagnetic Interference (EMI) on the

reference circuit. EMI can usually be detected by monitoring engine RPM with Tech 2. A sudden increase in

engine speed with little change in actual engine RPM, is indicative that EMI is present. If the problem exists,

check routing of secondary wires and also check ground circuit.

• Intake and exhaust manifold passage for casting flash.

ROUGH, UNSTABLE, OR INCORRECT IDLE , S TALLING

DEFINITION: Engine runs unevenly at idle. If bad enough, the vehicle may shake. Also, the idle may vary in RPM

(called "hunting"). Either condition may be bad enough to cause stalling. Engine idles at incorrect speed.

PRELIMINARY CHECKS:

• Perform the careful visual/physical checks as described at the start of this Section – "IMPORTANT

PRELIMINARY CHECKS".

• For vacuum leaks, they will cause a fluctuating unstable idle.

• PCM grounds are clean, tight and in there correct location(s). Refer to PCM wiring diagrams.

• Idle Air Control (IAC) system for proper operation, refer TABLE A-7.1 IDLE AIR CONTROL in 6C2-2A

DIAGNOSTIC TABLES in this Section.

• For proper ignition voltage output using spark tester, Tool No. 7230 (also released as ST-125).

• Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or

heavy deposits.

ENGINE MECHANICAL CHECKS:

• Perform a cylinder compression check. Remove relays ‘X4’ (engine control – EFI) and ‘X16’ (fuel pump) from

the underhood electrical centre, before performing test.

• For correct camshaft valve lift and timing or weak valve springs.

FUEL SYSTEM CHECKS:

• For contaminated or incorrect fuel.

• For injectors that are restricted or not operating. Perform an Injector Balance Test, using Tech 2.

• For injectors leaking, or incorrect fuel pressure, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this

Section.

• Monitoring Long term fuel trim will help identify the cause of the problem. If the system is running lean (Long

Ter m Fuel T rim near +25%), refer to "Diagnostic Aids " with DT C 44 or 64 in 6C2-2A DIAGNOST IC TABLES in

this Section. If the system is running rich (Long Term Fuel Trim near –22%), refer to "Diagnostic Aids" with

DTC 45 or 65 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• For fuel in pressure regulator hose. If fuel is present, replace regulator assembly.

• The Oxygen Sensors (HO2S) should respond quickly to different throttle positions, if they do not, check the

Oxygen Sensors (HO2S) for silicon contamination from fuel, or use of improper RTV sealant. The sensor will

have a white, powdery coating, and will result in a high but false signal voltage (rich exhaust indication). The

PCM will then reduce the amount of fuel delivered to the engine, causing a severe driveability problem.

ADDITIONAL CHECKS:

• MAF sensor, refer to TABLE A-6.1 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Throttle linkage for sticking or binding.

• IAC operation, refer TABLE A-7.1 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• A/C signal to PCM, Tech 2 should indicate A/C is being requested whenever A/C is selected and the blower

switch is "ON." If problem exists with A/C "ON," check A/C system operation TABLE A-11.1 or TABLE A-11.3 in

6C2-2A DIAGNOSTIC TABLES in this Section.

• PCV valve for pr oper operation. Refer 2.1 POSITIVE CRANKCASE VENTILAT ION VALVE, in 6E2 EMISSION

CONTROL V6 S/C ENGINE, in the MY 2003 VY and V2 Series Service Information.

• Service Bulletins for updates.

• For broken engine support mounts.

• Generator output voltage. Repair if less than 9 or more than 16 volts.

• Battery cables and ground straps should be clean and secure. Erratic voltage will cause IAC to change its

position resulting in poor idle quality.

POOR FUEL ECONOMY

DEFINITION: Fuel ec onomy, as m easur ed by an actual road test, is notic eably lower than expected. Also, economy

is noticeably lower than it was on this vehicle at one time, as previously shown by an actual road test.

IMPORTANT: A m isfiring engine will have excessive unburned oxygen in the exhaust, and the "Closed-Loop" fuel

control system oxygen sensor will interpret a lean exhaust. The PCM will cause an increase in fuel injector

pulsewidth in attempts to overcome the lean exhaust indication.

PRELIMINARY CHECKS:

• Perform the careful visual checks as described at the start of this Section – "IMPORTANT PRELIMINARY

CHECKS".

• Visually/physically check: Vacuum hoses for splits, kinks, and proper connections.

• Check owner's driving habits.

– Is A/C "ON" full time (Defroster mode "ON")?

– Are tyres at correct pressure?

– Are excessively heavy loads being carried?

– Is acceleration too much, too often?

• Check air cleaner element (filter) for dirty or being blocked.

• Check for correct size tyres. Oversize tyres will cause speedometer/odometer to be "slow," and indicated fuel

usage may increase.

IGNITION SYSTEM CHECKS:

• Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or

heavy deposits. Repair or replace as necessary.

COOLING SYSTEM CHECKS:

• Engine coolant level.

• Engine thermostat for faulty part (always open) or for wrong heat range.

ENGINE MECHANICAL CHECKS:

• Compression. Remove relays ‘X4’ (engine control – EFI) and ‘X16’ (fuel pump) from the underhood electrical

centre, before performing test.

ADDITIONAL CHECKS:

• TCC operation. Tech 2 should indicate an rpm drop, when the TCC is commanded "ON."

• For dragging brakes.

• For exhaust system restriction, refer to TABLE A-13 in 6C2-2A DIAGNOSTIC TABLES in this Section..

• For proper calibration of speedometer.

• Induction system and crankcase for air leaks.

• Exhaust system for air leaks before the oxygen sensor(s).

FUEL SYSTEM CHECKS:

• For leaking injectors or high fuel pressure or an external fuel leak.

• Long Term Fuel Trim values using Tech 2, for an abnormally high reading; i.e. greater than 10% (possibly

caused by engine misfiring).

BACKFIRE

DEFINITION: Fuel ignites in intake manifold, or in exhaust system, making loud popping noise.

PRELIMINARY CHECKS:

• Perform the careful visual/physical checks as described at the start of this Section – "IMPORTANT

PRELIMINARY CHECKS".

IGNITION SYSTEM CHECKS:

• Proper ignition coil output voltage with spark tester, Tool No. 7230 (also released as ST-125).

• Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or

heavy deposits. Repair or replace as necessary.

• Spark plug wires for proper routing to avoid cross-fire and correct resistance.

ENGINE MECHANICAL CHECKS:

• Compression - Look for sticking or leaking valves. Remove relays ‘X4’ (engine control – EFI) and ‘X16’ (fuel

pump) from the underhood electrical centre, before performing test.

• Valve timing.

• Intake and exhaust manifold passages for casting flash.

FUEL SYSTEM CHECKS:

• Perform "Fuel S ystem Diagnosis Check", refer TABLE A-4.3. in 6C2-2A DIAGNOSTIC TABLES in this Section.

EXCESSIVE EXHAUST EMISSIONS OR ODOURS

DEFINITION: Vehicle fails an emission test. Vehicle has excessive "rotten egg" smell. Excessive odours do not

necessarily indicate exce ssive emissions.

PRELIMINARY CHECKS

• Perform "On-Board Diagnostic System Check" in 6C2-2A DIAGNOSTIC TABLES in this Section.

IGNITION SYSTEM CHECKS:

• Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or

heavy deposits. Repair or replace as necessary.

COOLING SYSTEM CHECKS:

• If the Tech 2 indicates a very high engine coolant temperature and the system is running lean, check:

– Engine coolant level.

– Engine thermostat for faulty part (always open) or for wrong heat range.

– Cooling fan operation.

FUEL SYSTEM CHECKS:

• For contaminated or incorrect fuel.

NOTE: If the system is running RICH (Long T erm F uel Tr im near –22%) - Refer to "Diagnostic Aids" with DT Cs

45 or 65 in 6C2-2A DIAGNO ST IC TABLES in this Section. If the system is running LEAN ( Long T e rm F uel T r im

near +25%) - Refer to "Diagnostic Aids" with DTCs 44 or 64 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• For properly installed fuel tank cap.

• Fuel pressure, refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• Canister for fuel loading.

ADDITIONAL CHECKS:

• For vacuum leaks.

• Burnt valves.

• For lead contamination of catalytic converter (look for the removal of the fuel filler neck restriction).

• Carbon build-up. Remove carbon with top engine cleaner. Follow instructions on can.

• For exhaust system restriction, refer TABLE A-13 in 6C2-2A DIAGNOSTIC TABLES in this Section.

• PCV valve for being plugged or stuck, or fuel in the crankcase.

• Service Bulletins for updates.

DIESELING, RUN-ON

DEFINITION: Engine continues to run after ignition is turned "OFF," but runs very roughly.

PRELIMINARY CHECKS:

• Perform the careful visual/physical checks as described at the start of this Section – "IMPORTANT

PRELIMINARY CHECKS".

FUEL SYSTEM CHECKS:

• Injectors for leaking. Perform "Fuel System Diagnosis Check", refer TABLE A-4.3 in 6C2-2A DIAGNOSTIC

TABLES in this Section.

IGNITION SYSTEM CHECKS:

• If engine runs smoothly, check ignition switch and adjustment.

RICH/LEAN SYMPTOM CHART

CIRCUIT DESCRIPTION:

The Rich/Lean Symptom Chart is an organised appr oach to identifying a driveability com plaint that may be caused

by an over rich or over lean operating condition. Under standing the Chart and us ing it corr ectly will reduce diagnostic

time and improve customer satisfaction. Start at the left side of the Chart and work to the right.

TEST DESCRIPTION:

NOTE: Number(s) below refer to step number(s) on the diagnostic chart.

1. This is a partial list of possible customer complaints and what the air/fuel mixture must be to cause such a

condition.

2. A lean exhaust m eans that there is a lot of ox ygen in the ex haust str eam . Lots of oxygen in the exhaust stream

means a low oxygen sensor signal voltage. Lean = lots of oxygen = low oxygen sensor signal voltage. A rich

exhaust means that there is some fuel and very little oxygen in the exhaust stream.

3. The oxygen sensor signal to the PCM determines what the PCM should do to compensate for the present

condition. Depending upon the severity of the problem , the PCM will compensate f or the condition by changing

the shor t term f uel trim and long term fuel trim values either higher or lower. A short term f uel trim value above

0% m eans the PCM will add m ore fuel to the engine, by increasing the injec tor pulsewidth, thus mak ing a lean

engine run r icher . A shor t ter m f uel trim value below 0% means the PCM will decr eas e the amount of f uel to the

engine, by decreasing the injector pulse width, thus making a rich engine run leaner.

4. This list represents areas where you should look to find the root cause of the customer complaint. Not every

cause of the symptom is listed here, however, the items listed provide a good general description of areas to

look at.

DIAGNOSTIC AIDS:

Driveability complaints may be caused by the PCM, system components or electrical faults, however, a basic engine

problem may also present a symptom sim ilar to an electr ical failure. Rem em ber to check the air cleaner and all the

basic engine components, there could be worn rings, worn camshaft lobes, collapsed lifters, misaligned timing

chain, vacuum leaks etc.

RICH/LEAN SYMPTOM CHART

VEHICLE OPERATION OXYGEN SENSOR

OPERA TION SHORT AND LONG TERM

FUEL TRIM OPERATION POSSIBLE CAUSES

CUSTOMER

DRIVEABILITY

COMPLAINT/SYMPTOM

EXHAUST

STREAM

STATUS

OXYGEN

SENSOR

VOLTAGE

LEAN Air/Fuel Mi xture

Short Term Fuel Trim and Long Term

Fuel Trim are numeric al ly i ncreasing

High (above 0%) possible DTC 44 or

LEAN Air/Fuel Mixture

– High NOx Emissi ons

– Stumbles/Stalls

– Surges

– Poor Perform ance

High

Oxygen

Content

LEAN

EXHAUST

0 mV

+ 25 %

RICH COM MAND

ADD FUEL

DTC 64. Oxygen Sensor voltage

between 450 mV and 0 mV.

Cause: Fuel s ys t em not i n control.

Check For:

• Poor PCM grounds.

• Intak e manif ol d vacuum l eak.

• Restricted fuel filter.

• Low fuel pressure.

• Water c ontami nation in fuel .

• Lean (restricted flow), f uel

injector(s).

16 to 1 Air/Fuel Mixture

Increas e I nj ector Pul se

Width

Oxygen Sensor being “Trick ed” Lean.

Cause: Too much air in exhaust

stream above oxygen sensor.

• Cylinders not firing (misfire),

sending unburned air/fuel mixture

into exhaust.

• Cracked or leaking exhaust

manifold.

• Oxygen sens or mounting is loose,

dirty or has no sealing washer.

14.7:1 Air/Fuel Mixture 450 mV 0 % NO

CHANGE

RICH Air/Fuel Mixture

Short Term Fuel Trim and Long Term

Fuel Trim are numeric al ly decreasing

low (below 0%) possible DTC 45 or

DTC 65.

Oxygen Sensor voltage between 450

mV and 1,000 mV.

13 to 1 Air/Fuel Mixture

RICH Air/Fuel Mixture

– High HC, CO

Emissions

– Black Smoke

– Catalytic Converter

Odour

Decrease I nj ector Pul se

Width

REMOVE FUEL

LEAN COMMAND

Cause: Fuel s ys t em not i n control.

Check For:

• Restricted (dirt y) air filter.

• Leaking injector(s).

• High fuel pres sure.

• Restricted fuel ret urn l i ne.

• ECT tem perature value low.

• Oxygen Sensor contaminated

(covered w/ foreign s ubstance).

• Engine oil c ontami nated with fuel.

• Cani ster purge c ont i nuously

purging.

– Fouled Spark Plugs RICH

EXHAUST 1, 000 mV –22% Oxygen Sensor being “Trick ed” Ri ch.

Cause: Not enough air i n exhaust .

Low

Oxygen

Content

• Restricted exhaust system.

• Oxygen Sensor ground, wire

open, or has a poor c onnection.

• Oxygen Sens or poi soned

(impregnated with foreign

substance).

• When using Tech 2 to observe Short Term Fuel Trim and Long Term Fuel Trim values, remember that, if the system is in

control, no action is required unless there is a driveabilit y s ymptom present.

AUTOMATIC TRANSMISSION SYMPTOM TABLES

OIL PRESSURE HIGH OR LOW

Checks Causes

Oil Pump Assembly • Pressure regulator valve stuck

• Pressure regulator valve spring

• Rotor guide omitted or disassembled

• Rotor cracked or broken

• Reverse boost valve or sleeve stuck, damaged or incorrectly assembled

• Orifice hole in pressure regulator valve plugged

• Sticking slide or excessive rotor clearance

• Pressure relief ball not seated or damaged

• Porosity in pump cover or body

• Wrong pump cover

• Pump faces not flat

• Excessive rotor clearance

Oil Filter • Intake pipe restricted by casting flash

• Cracks in filter body or intake pipe

• O-ring seal missing, cut or damaged

• Wrong grease used on rebuild

Valve Body • Manual valve scored or damaged

• Spacer plate or gaskets incorrect, misassembled or damaged

• Face not flat

• 2-3 Shift valve stuck

• Checkballs omitted or misassembled

Pressure Control

Solenoid Valve • Damage to pins

• Contamination

• Damaged seals

Case • Case to valve body face not flat

HARSH SHIFTS/INACCURATE SHIFT POINTS

Checks Causes

Throttle Position

Sensor • Open or shorted circuit

Vehicle Speed Sensor • Open or shorted circuit

TFP Manual Valve

Position Switch • Contamination

• Damaged seals

Trans Fluid

Temperature Sensor • Open or shorted circuit

Engine Coolant

Temperature Sensor • Open or shorted circuit

Pressure Control

Solenoid Valve • Damage to pins

• Contamination

Oil Pump Assembly • Stuck pressure regulator valve

• Sticking pump slide

Valve Body Assembly • Spacer plate or gaskets misassembled, damaged or incorrect

Case • Porous or damaged valve body pad

• 2-4 Servo Assembly :

– 2-4 accumulator porosity

– Damaged servo piston seals

– Apply pin damaged or improper length

• 2-4 Band Assembly:

– Burned

– Anchor pin not engaged

TP Sensor • Disconnected

• Damaged

Vehicle Speed Sensor • Disconnected

• Damaged

• Bolt not tightened

1ST GEAR RANGE ONLY - NO UPSHIFT

Checks Causes

Valve Body • The 1-2 Shift valve is sticking

• The spacer plate or gaskets are mispositioned or damaged

Case • The case to valve body face is damaged or is not flat

Shift Solenoid Valves • Stuck or damaged

• Faulty electrical connection

2-4 Servo Assembly • The apply passage in the case is restricted or blocked

• Nicks or burrs on the servo pin or on the pin bore in the case

• Fourth servo pistons installed backwards

2-4 Band Assembly • The 2-4 band is worn or damaged

• The band anchor pin is not engaged

Vehicle Speed Sensor • No signal.

SLIPS IN 1ST GEAR

Checks Causes

Forward Clutch

Assembly • Clutch plates worn

• Porosity or damage in forward clutch piston

• Forward clutch piston inner and outer seals missing, cut or damaged

• Damaged forward clutch housing

• Forward clutch housing retainer and ball assembly not sealing or damaged

Forward Clutch

Accumulator • Piston seal missing, cut or damaged

• Piston out of its bore

• Porosity in the piston or valve body

• Stuck abuse valve

Input Housing and

Shaft Assembly • Turbine shaft seals missing, cut or damaged

Valve Body • 1-2 Accumulator valve stuck

• Face not flat, damaged lands or interconnected passages

• Spacer plate or gaskets incorrect, mispositioned or damaged

Low Roller Clutch • Damage to lugs to inner ramps

• Rollers not free moving

• Inadequate spring tension

• Damage to inner splines

• Lube passage plugged

Torque Converter • Stator roller clutch not holding

1-2 Accumulator

Assembly • Porosity in piston or 1-2 Accumulator cover and pin assembly

• Damaged ring grooves on piston

• Piston seal missing, cut or damaged

• Valve body to spacer plate gasket at 1-2 Accumulator cover, missing or damaged

• Leak between piston and pin

• Broken 1-2 Accumulator spring

Line Pressure • Refer to Oil Pressure High or Low

2-4 Servo Assembly • 4th Servo piston in backward

SLIPPING OR ROUGH 1-2 SHIFT

Checks Causes

Valve Body Assembly • 1-2 Shift valve train stuck

• Gaskets or spacer plate incorrect, mispositioned or damaged

• 1-2 Accumulator valve stuck

• Face not flat

2-4 Servo Assembly • Apply pin too long or too short

• 2nd servo apply piston seal missing, cut or damaged

• Restricted or missing oil passages

• Servo bore in case damaged

2nd Accumulator • Porosity in 1-2 accumulator housing or piston

• Piston seal or groove damaged

• Nicks or burrs in 1-2 accumulator housing

• Missing or restricted oil passage

2-4 Band • Worn or mispositioned

Oil Pump Assembly or

Case • Faces not flat

NO 2-3 SHIFT OR 2-3 SHIFT SLIPS, ROUGH OR HUNTING

Checks Causes

Torque Converter • Internal damage.

Valve Body Assembly • 2-3 Shift valve train stuck.

• Accumulator valve stuck.

• Gaskets or spacer plate incorrect, mispositioned or damaged.

2-4 Servo Assembly • 2nd apply servo piston seals missing, cut or damaged.

Input Housing

Assembly • Clutch plates worn (3-4 or forward).

• Excessive clutch plate travel.

• Cut or damaged 3-4 or forward clutch seals.

• Porosity in input clutch housing or piston.

• 3-4 Piston checkball stuck, damaged or not seating.

• Restricted apply passages.

• Forward clutch piston retainer and ball assembly not seating.

• Sealing balls loose or missing.

Oil Pump Assembly • Stator shaft sleeve scored or off location.

Transmission Case • 3rd accumulator retainer and ball assembly not sealing.

2ND/3RD GEARS ONLY OR 1ST/4TH GEARS ONLY

Checks Causes

Shift Solenoid Valves • Sediment is in the valves.

• The electrical connection is faulty .

• Damaged seal.

THIRD GEAR ONLY

Checks Causes

DTC 81 • The electrical connection is faulty .

• Shorted or damaged.

3-2 FLARE OR TIE-UP

Checks Causes

3-2 Shift Solenoid • Shorted or damaged.

• Contamination.

• Damaged Seal.

NO 3-4 SHIFT, SLIPS OR ROUGH 3-4 SHIFT

Checks Causes

Oil Pump Assembly • Pump cover retainer and ball assembly omitted or damaged.

• Faces not flat.

Valve Body Assembly • Valves stuck:

– 2-3 Shift valve train.

– Accumulator valve.

– 1-2 Shift valve train.

– 3-2 Shift valve.

• Spacer plate or gasket incorrect, mispositioned or damaged.

2-4 Servo Assembly • Incorrect band apply pin.

• Missing or damaged servo seals.

• Porosity in piston, cover or case.

• Damaged piston seal grooves.

• Plugged or missing orifice cup plug.

Case • 3rd Accumulator retainer and ball assembly leaking.

• Porosity in 3-4 accumulator piston or bore.

• 3-4 Accumulator piston seal or seal grooves damaged.

• Plugged or missing orifice cup plug.

• Restricted oil passage.

Input Housing

Assembly • Refer to Slipping 2-3 Shift

2-4 Band Assembly • Worn or Disassembled

NO REVERSE OR SLIPS IN REVERSE

Checks Causes

Input Housing

Assembly • 3-4 Apply ring stuck in applied position.

• Forward clutch not releasing.

• Turbine shaft seals missing, cut or damaged.

Manual Valve Link • Disconnected.

Valve Body Assembly • 2-3 Shift valve stuck.

• Manual linkage not adjusted.

• Spacer plate and gaskets incorrect, mispositioned or damaged.

• Lo overrun valve stuck.

• Orificed cup plug restricted, missing or damaged.

Reverse Input Clutch

Assembly • Clutch plate worn.

• Reverse input housing and drum assembly cracked at weld.

• Clutch plate retaining ring out of groove.

• Return spring assembly retaining ring out of groove.

• Seals cut or damaged.

• Restricted apply passage.

• Porosity in piston.

• Belleville plate installed incorrectly.

• Excessive clutch plate travel.

• Oversized housing.

Lo and Reverse Clutch • Clutch plates worn.

• Porosity in piston.

• Seals damaged.

• Return spring assembly retaining ring mispositioned.

• Restricted apply passage.

NO PART THROTTLE OR DELAYED DOWNSHIFTS

Checks Causes

2-4 Servo Assembly • Servo cover retaining ring omitted or misassembled.

• 4th Apply piston damaged or misassembled.

• Servo inner housing damaged or misassembled.

Valve Body Assembly • 3-2 Downshift valve stuck.

• 4-3 Sequence valve body channel blocked.

HARSH GA RAGE SHIFT

Checks Causes

Valve Body Assembly • Orifice cup plug missing.

• Checkball missing.

NO OVERRUN BRAKING - MANUAL 3-2-1

Checks Causes

External Linkage • Not adjusted properly.

Valve Body Assembly • 4-3 Sequence valve stuck.

• Checkball mispositioned.

• Spacer plate and gaskets incorrect, damaged or mispositioned.

Input Clutch Assembly • Turbine shaft oil passages plugged or not drilled.

• Turbine shaft seal rings damaged.

• Turbine shaft sealing balls loose or missing.

• Porosity in forward or overrun clutch piston.

• Overrun piston seals cut or damaged.

• Overrun piston checkball not sealing.

NO TCC APPLY

Checks Causes

Electrical • 12 Volts not supplied to transmission.

• Outside electrical connector damaged.

• Inside electrical connector, wiring harness or solenoid damaged.

• Electrical short (pinched solenoid wire).

• Solenoid not earthed.

Converter • Internal damage.

Oil Pump Assembly • Converter clutch valve stuck or assembled backwards.

• Converter clutch valve retaining ring mispositioned.

• Pump to case gasket mispositioned.

• Orifice cup plug restricted or damaged.

• Solenoid O-ring seal cut or damaged.

• High or uneven bolt torque (pump body to cover).

Input Housing and

Shaft • Turbine shaft O-ring seal cut or damaged.

• Turbine shaft retainer and ball assembly restricted or damaged.

TFP Manual Valve

Position Switch • Contamination.

• Damaged seals.

Valve Body Assembly • TCC signal valve stuck.

• Solenoid O-ring leaking.

Solenoid Screen • Blocked.

TCC Solenoid Valve • Valve stuck.

Engine Speed Sensor • Incorrect or no signal.

Engine Coolant

Temperature Sensor • Temperature reading too low or too high.

DTCs 19, 21, 22, 28,

67, 81, 83, 84 –

Transmission Fluid

Temperature Sensor • Temperature reading incorrect

TORQUE CONVERTER CLUTCH SHUDDER

Checks Causes

Converter • Internal damage.

Oil Pump Assembly • Converter clutch valve stuck or assembled backwards.

• Restricted oil passage.

Input Housing and

Shaft • Turbine shaft O-ring seal cut or damaged.

• Turbine shaft retainer and ball assembly restricted or damaged.

Fluid Filter • Crack in filter body.

• Casting flash restricting filter neck.

• O-ring seal cut or damaged.

Miscellaneous • Low fluid pressure.

• Engine not tuned correctly.

Input Housing and

Shaft Assembly • Turbine shaft O-ring cut or damaged.

• Turbine shaft retainer and ball assembly restricted or damaged.

NO TCC RELEASE

Checks Causes

TCC Solenoid Valve • Internal ground

• Clogged exhaust orifice

Converter • Internal damage

Valve Body Assembly • The converter clutch apply valve is stuck in the apply position

Oil Pump Assembly • The converter clutch valve is stuck

PCM • External ground

DRIVES IN NEUTRAL

Checks Causes

Forward Clutch • The clutch does not release

Manual Valve Link • Disconnected

Case • The face is not flat

• Internal leakage exists

2ND GEAR START (DRIVE RANGE)

Checks Causes

Forward Clutch Sprag

Assembly • The sprag assembly is installed backwards.

NO PARK

Checks Causes

Parking Linkage • Actuator rod assembly bent or damaged.

• Actuator rod spring binding or improperly crimped.

• Actuator rod not attached to inside detent lever.

• Parking lock bracket damaged or not torqued properly.

• Inside detent lever not torqued properly.

• Parking pawl binding or damaged.

RATCHETING NOISE

Checks Causes

Parking Pawl • The parking pawl return spring is weak, damaged, or misassembled

FLUID OUT THE VENT

Checks Causes

Oil Pump • Chamber in pump body rotor pocket.

Miscellaneous • Fluid level – overfilled.

VIBRATION IN REVERSE AND WHINING NOISE IN PARK

Checks Causes

Oil Pump • Chamber in pump body rotor pocket.

Miscellaneous • Fluid level – overfilled.

NO DRIVE IN ALL RANGES

Checks Causes

Torque Converter • The converter to flex plate bolts are missing.

NO DRIVE IN DRIVE RANGE

Checks Causes

Torque Converter • The stator roller clutch is not holding.

• The converter to flex plate bolts are missing.

FRONT OIL LEAK

Checks Causes

Torque Converter • The welded seam is leaking.

• The converter hub is damaged.

Torque Converter Seal • The seal assembly is damaged.

• The garter spring is missing.

DELAY IN DRIVE AND REVERSE

Checks Causes

Torque Converter • Converter drainback

PCM CONNECTOR SYMPTOM TABLES

The following Powertrain Control Module (PCM) connector Symptoms Tables identifies the function of each pin of

the PCM connector, the c irc uit number, the wire colour , and the c avity of the com ponent to which the wire connects.

The left column in these table lists the PCM connector pins in ascending order. The tables may also be entered

from the r ight-m ost colum n, which lis ts poss ible symptom s that m ay be caused by a fault in each of the cir cuits. If a

problem in any of these circuits will cause a Diagnostic Trouble Code to be set, the DTC's are identified in the

second column from the right edge of the Table. (However, if a DTC has been s et, you should attem pt to diagnose

the condition using 6C2-2A DIAGNOSTIC TABLES - V6 ENGINE in this Section before diagnosing by symptom.)

The expected normal voltage for each circuit is shown for two conditions. Check the voltage with the ignition "ON"

but the engine not running, and with the engine running. Both checks are required for accurate diagnosis.

Reference notes are made for some circuits. These notes state conditions that cause varying voltages or mention

unique characteristics of the circuit. To measure the voltages, backprobe the PCM connector. Whenever

backprobing, be careful not to damage the connector. Careless backprobing may damage the connector seal

and/or terminal. Damaged pins will provide incorrect readings and cause additional system problems.

PCM CONNECTOR A84 X1

POWERTRAIN CONTROL MODULE CONNECTOR “A84 X1” SYMPTOMS TABLE

PINK 24 PIN – ROW ‘A’

PIN FUNCT ION CKT # WIRE

COLOUR COMPONENT/

CONNECTOR CAVITY NORMAL

VOLTAGES DTCs

AFFECTED POSSIBLE SYMPTOMS

FROM FAULTY CIRCUIT

IGN “ON” ENG RUN

A1 SYSTEM

GROUND 450 BK/RD OXYGEN SENSOR AND

ENGINE GROUND “E ” * * NONE NO START I F ALL

GROUND CIRCUITS ARE

OPEN.

A2 SYSTEM

GROUND 450 BK / RD ENGINE GROUND “F” * * NONE NO START IF ALL

GROUND CIRCUITS ARE

OPEN.

A3 PRIMARY

SERIAL DATA 800 RD/BK “DLC” 9 & B CM 3-5 3-5 31 NO SERIAL DATA .

NO CRANKING.

NO START.

A4 FUSED IGNITION

FEED 300 OG FUSE F10 12 13 NONE NO NO SERIAL DATA.

NO START.

A5 NOT USED - - - - - - -

A6 FUEL PUMP

RELAY

CONTROL

465 GN/WH FUEL PUMP RELA Y “2” (4)

(2) 13 NONE HARD TO ST ART, LONG

CRANK TIME, SEE

TABLE A-1.

A7 TP SENSOR

REFERENCE

VOLTAGE

416 GY TP SE NS OR “A” 5 5 21, 22 ROUGH IDLE.

HESITATION ON

ACCELERATION.

A8 BATTERY

VOLTAGE FEED 740 OG/BK FUSE F29 12 13 NONE NO START.

A9 NOT USED - - - - - - -

A10 NOT USED - - - - - - -

A11 NOT USED - - - - - - -

A12 NOT USED - - - - - - -

REFERE NCES IN ‘NORMA L V O LT A G ES’ COLUMNS:

(2) 12 VOLTS FOR FIRST TWO SECONDS AFTER IGNITION IS TURNED “ON” WI THOUT CRANKING THE ENGINE.

(4) 12 VOLTS WHEN FUEL P UMP IS RUNNING.

* LESS THAN 0. 50 VOLT.

** REFER TO WIRING DI A G RA MS .

PCM CONNECTOR A84 X1

POWERTRAIN CONTROL MODULE CONNECTOR “A84 X1” SYMPTOMS TABLE

PINK 24 PIN – ROW ‘B’

NORMAL

VOLTAGES

PIN FUNCT ION CKT # WIRE

COLOUR COMPONENT/

CONNECTOR CAVITY IGN “ON” ENG RUN

DTCs

AFFECTED POSSIBLE SYMPTOMS

FROM FAULTY CIRCUIT

B1 SYSTEM

GROUND 450 BK/RD * * NONE NO START IF ALL

GROUND CIRCUITS ARE

OPEN.

B2 SYSTEM

GROUND 450 BK/RD * * NONE NO START IF ALL

GROUND CIRCUITS ARE

OPEN.

B3 A/C PRESSURE

SENSOR S IGNAL 380 GN/BK A/C PRESSURE

SENSOR B18,

TERMINAL X1-C

1-2 1-2 95 INOP A/C SYSTEM.

B4 INTAKE AIR

TEMPERATURE

SENSOR

5089 BN IA T S ENSOR “A” 1.0

(6) 1.0

(6) 23, 25, 26 NONE.

B5 ECT SENSOR

SIGNAL 410 YE ECT SENSOR “A” 1.9

(6) 1.9

(6) 14, 15, 16 HARD START.

LONG CRANK TIME.

B6 TFT SENSOR

SIGNAL 1227 BK/YE TRANSMISSION PASS-

THRU-CONNECTOR “L”

TFT SENSOR

1.8

(6) 1.8

(6) 58

59 MAXIMU M L INE

PRESSURE, T ORQUE

CONVERTE R CLUT CH IN

SECOND, THIRD AND

FOURTH GEAR.

B7 A/C

REFRIGERANT

PRESSURE

SENSOR

REFERENCE

VOLTAGE

2700 PU/WH A/C PRESSURE

SENSOR B 18

TERMINAL “X1-B”

5 5 96 A/C INOP.

B8 BATTERY

VOLTAGE FEED 740 OG/BK FUSE F29 12 13 NONE NO START.

B9 NOT USED - - - - - - -

B10 NOT USED - - - - - - -

B11 TP SENSOR

SIGNAL 411 BU THROTTLE POSITION

SENSOR “C” (5) (5) 21, 22 POOR PERFORMANCE,

HIGH IDLE.

B12 INJECTOR

VOLTAGE

MONITOR LINE

639 RD FUEL INJECTOR

MONITOR 12 13 57 NONE

REFERE NCES IN ‘NORMA L V O LT A G ES’ COLUMNS:

(5) 0.25 - 1.25 VOLTS MEASURED BETWEEN TERMINALS “B11” AND “B1” OR ABOUT 4.0 VOLTS AT WIDE OPEN

THROTTLE.

(6) VARIES WITH TEMPERATURE.

* LESS THAN 0.50 V OLT.

** REFER TO WIRING DIAGRAMS.

PCM CONNECTOR A84 X2

POWERTRAIN CONTROL MODULE CONNECTOR “A84 X2” SYMPTOMS TABLE

PINK 32 PIN – ROW “C”

NORMAL

VOLTAGES

PIN FUNCT ION CKT # WIRE

COLOUR COMPONENT/

CONNECTOR CAV ITY IGN “ON” ENG RUN

DTCs

AFFECTED POSSIBLE SYMPTOMS

FROM FAULTY CIRCUIT

C1 TCC SOLENOID

“ON-OFF”

CONTROL

422 GY/RD TORQUE CONVERTER

CLUTCH SOLENOID “B” 12 13 67

(9) NO TCC AND NO

FOURTH GEAR IF IN

HOT MODE.

C2 1-2 SHIFT

SOLENOID ‘A’

CONTROL

1222 L-GN 1-2 SHIFT SOLENOID ‘ A ’

TERMINAL “B” 12 * 82

(9) 2nd and 3rd GEAR ONLY

OR 1st AND 4th GEAR

ONLY AN D MAXIMUM

LINE PRESSURE.

C3 2-3 SHIFT

SOLENOID ‘B’

CONTROL

1223 YE/BK 2-3 SHIFT SOLENOID ‘B ’

TERMINAL “B” 12 * 81

(9) POSSIBLY THIRD GEAR

ONLY, NO TCC

OPERA TION, MAXIMUM

LINE PRESSURE.

C4 CANISTER

PURGE

SOLENOID

428 L-GN/YE CANISTER PURGE

SOLENOID TERMINAL

“B”

12 13 97 RICH EXHAUST.

C5 VEHICLE SPEED

SENSOR S IGNAL

SPEEDOMETER

5197 PU/WH INSTRUMENT

CONNECTOR “5” (1) (1) NONE INOPERATIVE

SPEEDOMETER.

C6 VEHICLE SPEED

SENSOR S IGNAL

HIGH

1231 D-BU/WH VEHICLE SPEED

SENSOR (1) (1) 24, 72,

94 MAXIMUM L INE

PRESSURE.

C7 IAC COIL “A”

HIGH 444 L-GN/BK IDLE AIR CONTROL

VALVE “C” NOT USEABLE 35 STALLING, ROUGH,

UNSTABLE OR

INCORRECT I DLE .

C8 IAC COIL “A”

LOW 1749 L-GN/WH IDLE AI R CONTROL

VALVE “D” NOT USEABLE 35 STALLING, ROUGH,

UNSTABLE OR

INCORRECT I DLE .

C9 IAC COIL “B”

LOW 1748 L-BU/ BK IDLE AI R CONTROL

VALVE “B” NOT USEABLE 35 STALLING, ROUGH,

UNSTABLE OR

INCORRECT I DLE .

C10 IAC COIL “B”

HIGH 1747 L-BU/WH IDLE AI R CONTROL

VALVE “A” NOT USEABLE 35 STALLING, ROUGH,

UNSTABLE OR

INCORRECT I DLE .

C11 TORQUE

REQUEST (MMR) 463 OG/WH ABS/TCS MODULE “13” 10-12 10-12 - -

C12 KNOCK SENSOR

(ESC) SIGNAL

INPUT

496 WH/RD KNOCK SENSOR 1.3 mm

Vacuum 25.5 mm

Vacuum 43

(9) LACK OF

PERFORMANCE, P OOR

FUEL ECONOMY.

C13 3-2 CONTROL

SOLENOID 898 GN/WH 3-2 CONTROL

SOLENOID 12 * 66 SOFT LANDING INTO

THIRD GEAR STAY IN

THIRD GEA R

C14 3-2 CONTROL

FEEDBACK 898 GN/WH CONTROL CIRCUIT 12 * 66 S O FT LA NDING INTO

THIRD GEAR STAY IN

THIRD GEA R

C15 TCC SOLENOID

PWM FEEDBACK 418 BN TCC CONTROL

CIRCUIT 12 13 83 TCC INOP.

C16 TCC SOLENOID

PWM 418 BN TCC CONTROL

CIRCUIT 12 13 83 TCC INOP.

REFERENCES IN ‘NORMAL VOLTAGES/DTCs AFFECTED’ COLUMNS:

(1) VARIES FROM 0.10 TO ABOUT 13 V, DEPENDING ON POSITION OF DRIVE WHEELS W HEN VEHICLE IS MOVING.

(9) OPEN/EARTHED CIRCUIT.

* LESS THAN 0.50 VOLT.

** REFER TO WIRING DI AGRAMS.

PCM CONNECTOR A84 X2

POWERTRAIN CONTROL MODULE CONNECTOR “A84 X2” SYMPTOMS TABLE

PINK 32 PIN – ROW ‘D”

NORMAL

VOLTAGES

PIN FUNCT ION CKT # WIRE

COLOUR COMPONENT/

CONNECTOR CAVITY IGN “ON” ENG RUN

DTCs

AFFECTED POSSIBLE SYMPTOMS

FROM FAULTY CIRCUIT

D1 MAF SENSOR 492 B N/ WH MASS AI R FLOW

SENSOR TERMINAL “A” 4.8 4.2 32 RICH EXHAUST.

D2 NOT USED - - - - - - -

D3 CAMSHAFT

POSITION

SENSOR SIGNAL

630 BK IGNITION MODULE “F” 4.8 4.4 48, 49 V-6 ONLY, NO

SEQUENTIAL FUEL

INJECTION.

D4 CRANKSHAFT

18X SIGNAL 647 L-BU/BK IGNITION MODULE “C” 5 2.7

3.0

(9) NO START.

D5 VEHICLE SPEED

SENSOR SIGNAL

LOW

1230 TN VEHICLE SPEED

SENSOR * * 24, 72

94 MAXIMUM L INE

PRESSURE SE COND

GEAR ONLY.

D6 NOT USED - - - - - - -

D7 NOT USED - - - - - - -

D8 NOT USED - - - - - - -

D9 BYPASS

CONTROL 424 TN/BK IGNITION MODULE “B” 0 4. 7 42 POOR PERFORMANCE.

D10 ELECTRONIC

SPARK TIMING

OUTPUT

423 WH IGNITION MODULE “A ” 0 2.0 41, 42 HARD TO ST A RT,

STALLS.

D11 REFERENCE

SIGNAL LOW 453 BK / RD IGNITION MODULE “L” * * NONE POOR PERFORMANCE.

D12 REFERENCE

SIGNAL HIGH 430 PU IGNITION MODULE “D” 4.8 2.3 12 NO ST A RT.

D13 RH O2 SENSOR

SIGNAL 1666 GY OXYGEN SENSOR 450

mv (4) 63, 64, 65 NO “CLOSED LOOP”

OPERATION (9).

D14 RH O2 SENSOR

GROUND 1667 GY/BK OXYGEN SENSOR AND

ENGINE GROUND * * 63, 64 NO “CLOS ED LOOP”

OPERATION (8).

D15 LH O2 SENSOR

SIGNAL 1665 PU OXYGEN SENSOR 450

mv (4) 13, 44, 45 NO “CLOSED LOOP”

OPERATION (9).

D16 LH O2 SENSOR

GROUND 1664 L-BU/BK OXYGEN SENSOR AND

ENGINE GROUND * * 13, 44 NO “CLOS ED LOOP”

OPERATION (8).

REFERENCES IN ‘NORMAL VOLTAGES/DTCs AFFECTED’ COLUMNS:

(1) VARIES FROM 0.10 V TO ABOUT 8.5 V, DEPENDING ON POSITION OF DRIVE WHEELS WHEN VEHICLE IS MOVING.

(4) VOLTAGE SHOULD VARY B ETWE E N 100 mV – 1, 000 mV.

(8) EARTHED CIRCUIT.

(9) OPEN/EARTHED CIRCUIT.

* LESS THAN 0.50 VOLT.

** REFER TO WIRING DI AGRAMS

PCM CONNECTOR A84 X3

POWERTRAIN CONTROL MODULE CONNECTOR “A84 X3” SYMPTOMS TABLE

PINK 32 PIN – ROW ‘E”

NORMAL

VOLTAGES

PIN FUNCT ION CKT # WIRE

COLOUR COMPONENT/

CONNECTOR CAVITY IGN “ON” ENG RUN

DTCs

AFFECTED POSSIBLE SYMPTOMS

FROM FAULTY CIRCUIT

E1 BOOST

CONTROL

SOLENOID

1724 BK/OG BOOST CONTROL

SOLENOID TERMINAL

“A”

12 13 NONE FULL BOOST, B OOS T

SYSTEM INOP.

E2 FUEL INJECTOR

#3 CONTROL 1746 PU FUEL INJECTOR #3 12 13 NONE ROUGH IDLE , HARD TO

START.

E3 FUEL INJECTOR

#2 CONTROL 1745 GN FUEL I NJ ECTOR #2 12 13 NONE ROUGH IDLE, HARD TO

START.

E4 FUEL INJECTOR

#5 CONTROL 845 BN/YE FUEL INJE CTOR #5 12 13 NONE ROUGH I DLE , HARD TO

START.

E5 FUEL PUMP

CONTROL

MODULE (PWM)

DRIVER

260 L-BU FUEL PUMP CONTROL

MODULE TERMINA L “7” * 3.0–3.4 V NONE POOR PERFORMANCE .

E6 PRNDL “A” 771 BU/WH PRNDL SWITCH

TERMINAL “A’ * * NONE IMPROPER GEAR

INDICA T E D ON

INSTRUMENT PANEL (9).

E7 PRNDL “B” 772 YE PRNDL SWITCH

TERMINAL “D” 12 13 NONE IMPROPER GEAR

INDICA T E D ON

INSTRUMENT PANEL (9)

E8 PRNDL “C” 773 GY PRNDL SWITCH

TERMINAL “B” 12 13 NONE IMPROPER GEAR

INDICA T E D ON

INSTRUMENT PANEL (9).

E9 NOT USED – – – – – – –

E10 NOT USED – – – – – – –

E11 NOT USED – – – – – – –

E12 231 BU OIL PRESSURE

SWITCH, TERMINAL ‘ A’ * 13 NONE

E13 NOT USED – – – – – – –

E14 PRESSURE

CONTROL

SOLENOID LOW

1229 GY/BU TRANSMISSION PASS-

THRU CONNECTOR “E ”,

PRESS URE CONTROL

SOLENOID.

* 6.8 73 (8) MAXIMUM LINE

PRES S URE, HARD

SHIFT.

E15 PRESSURE

CONTROL

SOLENOID HIGH

1228 RD TRANSMISSION PASS-

THRU CONNECTOR “C”,

PRESS URE CONTROL

SOLENOID.

1.1 1.3 73 MAXIMUM LINE

PRES S URE, HARD

SHIFT.

E16 ECT/TP SENSOR

GROUND 2752 BK/YE ECT SENSOR “B”

TP SENSOR “B” * * 15, 21 (8) HARD S T ART, HIGH

IDLE.

REFERENCES IN ‘NORMAL VOLTAGES/DTCs AFFECTED’ COLUMNS:

(2) 12 VOLTS WHILE ENGINE IS CRANKING. LESS THAN 0.05 VOLTS WHEN STARTER IS NOT OPERATING.

(3) WITH A IR CONDITI ONING “ON” 0 VOLTS , WIT H AIR CONDITIONING “OFF” 13 V O LT S .

(6) VARIES WITH TEMPERATURE.

(7) WITH ENGI NE COOLING FAN “ON”; 0 VOLTS, WI TH ENGINE COOLING FA N “OFF”; 13 VOLTS.

(8) OPEN.

(9 OPEN/EARTHED CIRCUIT.

* LESS THAN 0.50 VOLT.

** REFER TO WIRING DI AGRAMS

A84 V6 S/C – X3

PCM CONNECTOR A84 X3

POWERTRAIN CONTROL MODULE CONNECTOR “A84 X3” SYMPTOMS TABLE

PINK 32 PIN – ROW ‘F”

NORMAL

VOLTAGES

PIN FUNCT ION CKT

No. WIRE

COLOUR COMPONENT/

CONNECTOR CAVITY IGN “ON” ENG RUN

DTCs

AFFECTED POSSIBLE SYMPTOMS

FROM FAULTY CIRCUIT

F1 FUEL INJECTOR

#4 CONTROL 844 BN/ WH FUEL INJECTION #4 12 13 NONE ROUGH IDLE , HARD TO

START.

F2 FUEL INJECTOR

#1 CONTROL 1744 BU FUEL INJECTOR #1 12 13 NONE ROUGH IDLE, HA RD TO

START.

F3 FUEL INJECTOR

#6 846 YE FUEL INJ E CTOR #6 12 13 NONE ROUGH IDLE, HARD TO

START.

F4 A/C RELAY

CONTROL 459 L-GN/B K A/C RELA Y “2” 12 (3) NONE ROUGH IDLE, NO AIR

CONDITIONING.

F5 START RELAY

CONTROL 275 GY/ B U STA RT RELAY “86” * * 91 NO START.

F6 ENGINE COOLING

FAN RELA Y HIGH

SPEED CONTROL

335 BU/WH COOLING FAN RELAY

“86” 12 (7) NONE HIGH ENGINE

TEMPERATURE

OVERHEATING.

F7 TORQUE

ACHIEVED (MMI) 464 BK /WH ABS/TCS MODULE “27” 0.9 3.6 – –

F8 NOT USED – – – – – – –

F9 RANGE SIGNAL

“A” 1224 BN/YE TRANSMISSION PASS-

THRU CONNECTOR “N”

AND PRE S SURE

SW ITCH ASSEMBLY

12 13 28 MAXIMUM LINE

PRESSURE, NO 4TH

GEAR IF IN HOT MODE,

NO TCC OPERA T I O N.

F10 RANGE SIGNAL

“B” 1225 YE TRANSMISSION PASS-

THRU CONNECTOR “R”

AND PRE S SURE

SW ITCH ASSEMBLY

0 0 27

(8) NONE.

F11 RANGE SIGNAL

“C” 1226 GY TRANSMISSION PASS-

THRU CONNECTOR “P ”

AND PRE S SURE

SW ITCH ASSEMBLY

12 13 28

(8)

MAXIMUM L INE

PRESSURE, NO

FOURTH GEAR IF IN

HOT MODE, NO TCC

OPERATION.

F12 POWER/

ECONOMY

SWITCH

553 BU NORMAL/POWER

SWITCH 12 13 NONE NO POWE R SHIFTING.

F13 NOT USED – – – – – – –

F14 NOT USED – – – – – – –

F15 PRNDL P 776 WH PRNDL SWITCH

TERMINAL “C” * * IMPROPER GEAR

INDICA T E D ON

INSTRUMENT PANEL (9).

F16 IAT, TFT, A/C

REFRIGERANT

PRESSURE

SENSOR GROUND

2573 BK IAT SENS OR “B ”

TFT SENSOR “B”

PRESSURE SENSOR “A”

* * 23, 59,

(8)

SLIGHT HIGH IDLE TCC

APPLY EARLY.

REFERENCES IN ‘NORMAL VOLTAGES/DTCs AFFECTED’ COLUMNS:

(2) 12 VOLTS WHILE ENGINE IS CRANKING. LESS THAN 0.05 VOLTS WHEN STARTER IS NOT OPERATING.

(3) WITH A IR CONDITI ONING “ON” 0 VOLTS , WIT H AIR CONDITIONING “OFF” 13 V O LT S .

(6) VARIES WITH TEMPERATURE.

(7) WITH ENGI NE COOLING FAN “ON” 0 VOLTS, WITH E NGI NE COOLING FAN “OFF” 13 VOLTS.

(8) OPEN.

* LESS THAN 0.50 VOLT.

** REFE R T O WIRING DI AGRAMS.

A84 V6 S/C – X3

TESTING GROUNDS

Unusual displays in the instrument,

lamps that are dim or flash unexpectedly, stop lamps that come on when the indicators are used, are all classic

symptoms of ground problems.

This section discusses the importance of good ground circuits and starts by explaining some basic theory. Then, the

diagnosis of a solid-state circuit ground condition is detailed, to help show how to correct a problem, should it occur.

BASICS

For a circuit to operate properly, three things are

needed:

a. A good power supply to components;

b. Good components and,

c. Sound ground circuits.

Circuits are complete systems; current must flow

from beginning to end as designed, not hinder ed by

unexpected resistance anywhere in the circuit.

While some Technicians realise that the power

supply to a circuit must be free of unwanted

resistance, they can have difficulty in visualising

why a ground cir cuit mus t also be fr ee of unwanted

resistance.

For current to flow, the circuit must be complete; it

must pass through and out of a component like

water flowing thr ough a bathtub. With a f ree f lowing

tub (no plug inserted), the water can flow out as

freely as it flows in. In electrical term s , current m ust

also enter and leave components freely, if they are

to perform as they are designed.

Figure 6C2-2B-2

Sensitive, solid-s tate systems have their own ground points; high c urrent devic es (e.g. m otor s) do not ground at the

same location. High current devices can cause voltage spikes (sudden changes in voltage) when turned "ON" or

"OFF." To prevent these spikes from affecting sensitive solid-state circuits, two different types of different ground

location s ystem s are used. An exam ple is the use of a dedic ated wir e to connect an isolated ground junc tion block

to the battery negative terminal. This wire reduces the effect of spikes on sensitive circuits at the ground junction

block.

Solid-state circuits are particularly sensitive to poor circuit continuity because, in most cases, they use low current

flow. T his Sec tion on ground c ir cuits , c oncer ns itse lf with one solid-s tate device; the PCM. However, the information

included here can also be applied to all solid-state ground circuits.

Severe restrictions (i.e. resistance) in the ground circuit can cause resets and intermittent codes to set, in solid-state

systems. The PCM operates devic es such as fuel injec tors, idle air control (IAC) , etc., and rec eives inputs from low

voltage sensors, such as the mass air flow (MAF), crankshaft speed/position (CKP). These input and output devices

need good circuitry for correct operation.

Remember that, when maladjusted or defective sensors cause values to shift, they are usually accompanied by

driveability problems. If there is excessive resistance in the ground circuit, then the result will be the sam e; shifted

sensor outputs with corresponding driveability conditions. These conditions may not be severe enough to set

diagnostic trouble codes, but they will reduce vehicle efficiency and performance and may be noticed by the

customer.

Sensor circuit ground sensitivity – an example. Looking at the Throttle Position (TP) sensor circuit will provide an

example of how a little resistance in the ground circuit can cause problems. Figure 6C2-2B-3 shows a throttle

position sensor (1) first with a good ground circuit (‘A’) and then with a poor connection (‘B’) in the ground circuit.

Refer to this illustration, as you proceed through the text that follows:

First, the throttle position sensor consists of a resistor and a wiper and, one terminal of the resistor is connected to a

supply voltage (5 V) , while the other is connec ted to ground. As the wiper m oves across the resistor, the voltage of

the wiper terminal progressively changes, with a change in the throttle position. If the wiper is near the supply

voltage end of the resistor, the wiper output will approach the supply voltage (over 4.5 volts at wide open throttle).

As the wiper m oves toward the grounded end of the resistor , the voltage of the wiper output decreases to near zero

(about 0.5 volts for the closed throttle in this example). Note though, that the actual closed and wide open throttle

voltage specifications may vary for different engines. Also, the sensor output should never be greater than reference

supply voltage or less than 0.20 volts. (The PCM would set a DTC, should this situation occur.)

Figure 6C2-2B-3

In the f irst exam ple with a good gr ound circuit (‘A’), the T P sensor (1) is s hown with the wiper in the closed throttle

position. T he total voltage acros s the r esistor in the TP s ensor is 5 volts . The voltage drop f rom the resistor s ource

voltage terminal to the wiper is 4.5 volts. The voltage drop from the wiper to the resistor ground side is 0.5 volts. The

wiper output is 0.5 volts – a good value for this example of a closed throttle.

Now, look at the sensor with the bad signal caused by resistance in the ground circuit. The throttle position stays the

sam e but the sens or output voltage changes . In this exam ple the increas ed resistanc e causes an additional voltage

drop of 0.5 volts. The voltage drop from the wiper to ground is now 1.0 volt (0.5 + 0.5 = 1.0). Because the source

voltage is a constant 5 volts, the voltage drop from the source voltage input to the wiper can now be only 4 volts (5.0

- 1.0 = 4.0). The PCM now receives 1.0 Volt from the TP sensor. This is not a good value (in this example) of a

closed throttle.

Now you can see why good earths are needed and how sensitive some circuits can be.

GROUND CIRCUITS

How do you know which wires are ground wires, which connectors they go through, and whether they are connected

to a ground junction or the body?

Section 12P, WIRING DIAGRAMS in the MY 2003 VY and V2 Series Service Information should be used

whenever you are diagnosing any electrical condition, including earths. The individual circuits show the power and

ground circuits for components in specific systems.

If you suspec t s everal c ircuits are being af f ected by a poor or a back -f eed to ground, look at the circ uits to s ee how

the systems might interact. If they have any common ground wires, that is where you should start diagnosis.

Back -feeding is when current, s eeking ground, f eeds back through inac tive circuits (the r everse direction of normal

current flow) to find a path to ground. This can only happen when the active circuit (needing a ground) shares a

disconnected or poor ground with an inactive circuit and the voltage supply side of the inactive circuit feeds other

components with good earths.

PARALLEL GROUNDS

Some solid-state components use redundant ground circuits. That is, they have more than one wire connecting to

ground. The PCM has more than one ground circuit wire. There are several reasons for redundant earths.

The PCM has many low-current circuits, but the current from all these circuits (when they are active) adds up to a

larger current. Higher current loads are managed more easily with several regular size wires, rather than with one

large diameter wire.

Basic circuit theory shows that the effective

resistance of parallel resistors is less than any of

the individual resistors. The simple example shown,

proves this to be true and holds for even the small

resistance's in wires.

It follows that parallel wires provide the lowest

resistance. Because of them, in many solid-state

systems a problem with one of the ground wires

would not affect the circuit; the redundant wires

could handle the current load. For other solid-state

systems the loss of even one redundant ground

may affect operation, but the remaining ground

wire(s) may allow the vehicle to be driven.

Figure 6C2-2B-4

An example that can be difficult to locate, follows:

Symptom: A vehicle has driveability problems. However, whenever Tech 2 is hooked up and the vehicle tested,

none of the complaint sy mptoms are displayed.

Cause: T he PCM earths ar e not providing a good gr ound, henc e the res ulting dr iveability condition. When Tech 2 is

connected to the vehicle, a good gr ound path is provided for the PCM through the Data Link Connector (DLC). The

DLC uses a dif ferent ground than the PCM. Always test for dr iveability symptom s befor e hooking up T ech 2. If they

disappear when Tech 2 is hooked up, check the ground circuit for continuity.

The severity of the sym ptom (s) is propor tional to the s everity of the problem in the gr ound circuit. A com plete open

in the circuit has the most severe effect. Use the severity of the symptom(s) as an indication of the extent of the

open in the ground circuit.

CHECKING GROUNDS

Once you determine that the cause of the vehicle symptom(s) m ay be caused by a bad ground, it is time to check

for poor ground with one more tool: a high-impedance multimeter set to DC Volts.

The best way to check for poor ground connections in low-current solid-state circuits is to check the voltage drop.

To do this you need a high-impedance digital m ultimeter ( DMM) rated at a minim um of 10 megaohm s (10,000,000

ohms ) per volt. Any DMM with less impedanc e than this c an aff ec t the circuit being tested and also give an incorrec t

reading.

Start by checking the entire suspect ground circuit. With the DMM set on the 2 Volt DC scale, connect the black

negative lead to the battery negative (ground) term inal. (If you are using an auto-ranging m eter, sim ply set it to the

DC volts setting.)

Connect the red positive lead of the DMM to the ground terminal of the component to be tested. With the circuit

activated, check the voltage drop in the circuit. If the voltage reading is within specific ations, look f or a c ause other

than a poor ground at this component.

If the voltage drop reading is too high, proceed by isolating the cause of the high voltage drop. Move the positive

lead to the next connection in the ground circuit, working closer to the source voltage. (Keep the negative lead

connected to the battery negative terminal.) Be sure to check both sides of each in-line connector and both the

eyelet and the stud or screw at ground points. Repeat this process through the ground path until the voltmeter

reading is within specifications. The high resistance causing the ground problem is located between where you

obtained a good reading and the last high reading.

When a circuit uses redundant grounds be sure to check all the ground circuits for excessive voltage drop.

SOLID-STATE CIRCUIT VOLTAGE DROP SPECIFICATIONS

There ar e two ac c eptable maximum voltage dr ops for s olid-s tate c irc uits. If you are measur ing the voltage drop of a

circuit that will pass through a solid-state component before going to ground (such as the ECT sensor circuit

between the ECT sensor and the PCM), measured voltage cannot be higher than 0.060 volts (60 millivolts).

If you are measuring the voltage drop of a solid-state ground circuit anywhere in the ground path at or after the

solid-state component (such as the PCM ground circuit from the PCM to the battery), the maximum allowable

measured voltage is 0.020 volts (20 millivolts). If you measure a voltage above specifications, repair the ground

circuit.

ACCEPTABLE VOLTAGE DROP READINGS

BETWEEN SE NS O R A ND PCM 0.060 V (60 mV)

BETWEEN PCM AND BATTERY

NEGATIV E TE RMINA L 0.020 V (20 mV)

Checking the voltage drop in a solid-state sensor circuit.

Example ‘A’: Look again at an Engine Coolant Te mperatur e (ECT) s ensor circuit. With the voltmeter negative lead

connected to the negative battery terminal and the ignition ON, check the voltages at various points between the

ECT sensor B39, terminal "X1-B" and PCM connector A84, terminal "X3-E16" of the . A voltage reading of 0.060

volts or less with the meter positive lead at the ECT sensor, terminal "X1-B" indicates that the entire ground circuit

from the ECT sensor to the battery is continuous and s uffic iently low in resistanc e. A voltage reading of 0.060 volts

at the “splice" or the PCM connector terminal "X3-E16" would also be within specifications.

Figure 6C2-2B-5 Testing Voltage Drop Before and After the PCM

Legend

A. Voltage Drop Testing Before the PCM

1. Voltage Reading to be 0.060 Volt, Maximum B. Voltage Drop Testing After the PCM

2. Voltage Reading to be 0.020 Volt, Maximum

Example ‘B’ – When voltage measurements are made in the ground circuit after the PCM, the specification

changes. A voltage reading of 0.020 volts (20 millivolts) or less is within specification. If voltage is not within

specif ications chec k the dif ferent connec tors to find where the exc ess voltage is. Be s ure to check both sides of in-

line connectors and both the eyelet and the stud at ground points.

GROUND CREDIBILITY CHECK

Figure 6C2-2B-6 – Intake Air Temperature Sensor

CIRCUIT DESCRIPTION:

The ground c r edibility check can be either us ed at the beginning of all diagnos tic pr oc edures or it can be used when

no diagnostic trouble codes are set, but a symptom still exists.

TEST DESCRIPTION:

NOTE: Number(s) below refer to step number(s) on the diagnostic table.

. To properly test the voltage drop of the Powertrain Control Module (PCM) system ground, a load must be

present on the circuit.

Using Tech 2, select CANISTER PURGE. By turning "ON" the Purge solenoid, this will cause a sufficient

current draw on the system for testing.

2. Check connectors in ground circuit to find where the excessive voltage is. Make sure to check both sides of in-

line connectors.

DIAGNOSTIC AIDS:

Because the PCM operates on such small current even a minor corrosion problem will cause problems with the

system. Make sure the earths are clean and tight. Remember a good ground is about 25% of the total system

circuit. Normally you will check the wiring for; power, continuity, the load, but rarely check the ground. Powertrain

control module system earths are very important to proper operation.

B64 X119_GP5 AND GP6

Figure 6C2-2B-7

GROUND CREDIBILITY CHECK

STEP ACTION VALUE YES NO

1. Was the "On-Board Diagnostic" (OBD) System Check

performed? Go to Step 2. Go to

OBD

System Check

in this Section.

2. 1. Ignition "OFF"

2. Disconnect IAT sensor connector.

3. Using Digital Multimeter (DMM) set to DC voltage

scale, connect negative lead to negative battery

cable at battery and connect positive lead to the

black wire at the IAT sensor connector.

4. Ignition "ON"

5. Using Tec h 2, sele ct CANISTER PURGE.

6. Turn "ON'" Canister Purge, using the Soft keys.

Is voltage measured less than value shown.

0.060 volts

(60 Millivolts) No problem

found, continue

with symptom

diagnosis.

Go to Step 3

3. 1. Remove and thoroughly clean the PCM ground

terminals and connection.

2. Reassemble the PCM Ground terminals.

Is action complete?

Verify Repair –

CORRECTING PROBLEMS IN GROUND CIRCUITS

Once a high resistance condition in a ground circuit has been located, you must determine the actual cause.

If the problem is at a connector, check for bent, corroded, or loose connector terminals. Terminals m ust have a

slight drag when disassembled/assembled. If they slide apart/together without resistance, they will not provide a

good connection.

If the prob lem is at a st ud , bolt, or sheet metal screw, check for corrosion, paint, or loose connections. Paint can

be a very good insulator; good conductors, not insulators are needed for electrical connections.

Corrosion, paint, and other contaminants should be removed using a wire brush and/or emery cloth.

When assem bling ground wire eyelet's to ground points, be sur e an external type star w asher is placed below the

wire eyelet(s). If the system is marginal, you can also place a s tar washer between the nut or the sheet- metal s cr ew

and the top wire eyelet. Tighten the fastener to specification, making sure the star washer digs through any paint

into the mounting surface. Star washers also lock the fastener in place, preventing it from loosening.

All fasteners should be tightened so that the fastener head presses the ground wire eyelet or star washer to the

mounting surface and stops. Repair any stripped ground fasteners.

IMPORTANT: Do not over-tighten sheet-metal screws. Over-tightening can enlarge the hole and create a bad

ground. If the sheet-metal is enlarged, the screw will continue to turn: drill a new correctly sized hole for the screw.