
TABLE OF CONTENTS - Continued
P-0443 EVAP PURGE SOLENOID CIRCUIT................................143
P-0460 FUEL LEVEL UNIT NO CHANGE OVER MILES.......................148
P-0462 FUEL LEVEL SENDING UNIT VOLTS TOO LOW......................149
P-0463 FUEL LEVEL SENDING UNIT VOLTS TOO HIGH......................151
P-0500 NO VEHICLE SPEED SENSOR SIGNAL.............................153
P-0505 IDLE AIR CONTROL MOTOR CIRCUITS.............................159
P-0505B IDLE AIR CONTROL MOTOR CIRCUIT.............................164
P-0505C IDLE AIR CONTROL MOTOR CIRCUIT.............................165
P-0505D IDLE AIR CONTROL MOTOR CIRCUIT.............................166
P-0505E IDLE AIR CONTROL MOTOR CIRCUIT.............................167
P-0600 PCM FAILURE SPI COMMUNICATIONS.............................168
P-0601 INTERNAL CONTROLLER FAILURE................................169
P-0645 A/C CLUTCH RELAY CIRCUIT.....................................170
P-0703 BRAKE SWITCH STUCK PRESSED OR RELEASED..................172
P-1195 SLOW 1/1 O2S DURING CATALYST MONITOR.......................175
P-1281 ENGINE IS COLD TOO LONG.....................................177
P1282 FUEL PUMP RELAY CONTROL CIRCUIT.............................178
P-1294 TARGET IDLE NOT REACHED....................................180
P-1297 NO CHANGE IN MAP FROM START TO RUN........................183
P-1388 AUTO SHUTDOWN RELAY CONTROL CIRCUIT......................186
P-1389 NO ASD RELAY OUTPUT VOLTAGE AT PCM........................188
P-1391 INTERMITTENT LOSS OF CMP OR CKP............................191
P-1398 MISFIRE ADAPTIVE NUMERATOR AT LIMIT.........................198
P-1486 EVAP LEAK MONITOR PINCHED HOSE FOUND.....................200
P-1491 RADIATOR FAN CONTROL RELAY CIRCUIT.........................203
P-1494 LEAK DETECTION PUMP PRESSURE SWITCH......................206
P-1495 LEAK DETECTION PUMP SOLENOID CIRCUIT.......................209
P-1496 5 VOLT SUPPLY OUTPUT TOO LOW...............................212
P-1598 A/C PRESSURE SENSOR VOLTS TOO HIGH........................214
P-1599 A/C PRESSURE SENSOR VOLTS TOO LOW.........................217
P-1695 NO CCD MESSAGE FROM BODY CONTROLLER....................220
P-1696 PCM FAILURE EEPROM WRITE DENIED...........................222
P-1697 PCM FAILURE SRI MILE NOT STORED.............................222
P-1698 NO CCD MESSAGES FROM TCM..................................224
CHECKING 5 VOLT SUPPLY CIRCUIT.....................................226
* CHECKING EGR SYSTEM.............................................228
* CHECKING ENGINE VACUUM..........................................231
* CHECKING EVAPORATIVE EMISSION SYSTEM...........................232
* CHECKING FOR OXYGEN SENSOR SWITCHING..........................234
* CHECKING FUEL DELIVERY...........................................237
* CHECKING IDLE AIR CONTROL MOTOR.................................242
* CHECKING INTAKE AIR TEMPERATURE SENSOR.........................244
* CHECKING MAP SENSOR CALIBRATION................................245
* CHECKING MINIMUM IDLE AIR FLOW...................................246
* CHECKING OXYGEN SENSOR HEATER.................................247
* CHECKING PARK/NEUTRAL POSITION SWITCH..........................249
* CHECKING PCM POWER AND GROUND CIRCUITS.......................251
* CHECKING SECONDARY IGNITION.....................................252
* CHECKING THE ENGINE MECHANICAL SYSTEMS........................253
* CHECKING THROTTLE POSITION SENSOR CALIBRATION.................254
* CHECKING THE A/C PRESSURE SENSOR SIGNAL........................255
iii
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TABLE OF CONTENTS - Continued
SPEED CONTROL
P-1595 SPEED CONTROL SOLENOID CIRCUITS...........................256
P-1683 SPEED CONTROL POWER RELAY OR S/C 12V DRIVER..............256
SPEED CONTROL BRAKE SWITCH OUTPUT..............................261
SPEED CONTROL DENIED MESSAGE....................................263
SPEED CONTROL ON/OFF SWITCH......................................264
* CHECKING SPEED CONTROL OPERATION..............................266
STARTING
*9NO RESPONSE9CONDITION..........................................272
* CHECKING THE CAM AND CRANK SENSORS............................276
* CHECKING THE ENGINE MECHANICAL SYSTEMS........................277
* CHECKING THE FUEL SYSTEM........................................278
* CHECKING THE IDLE AIR CONTROL MOTOR.............................287
* CHECKING THE SECONDARY IGNITION SYSTEM.........................288
* NO CRANK CONDITION...............................................296
* START AND STALL CONDITION.........................................301
TRANSMISSION
P-0740 TORQUE CONV CLUTCH, NO RPM DROP AT LOCKUP...............302
P-0743 TORQUE CONVERTER CLUTCH SOLENOID CIRCUIT................304
P-1899 PARK/NEUTRAL SWITCH STUCK IN PARK OR IN GEAR..............307
ANTENNA FAILURE....................................................310
COP FAILURE.........................................................310
EEPROM FAILURE.....................................................310
INTERNAL FAULTS.....................................................310
RAM FAILURE.........................................................310
SERIAL LINK INTERNAL................................................310
STACK OVERFLOW FAILURE............................................310
SENTRY KEY IMMOBILIZER SYSTEM
PCM STATUS FAILURE.................................................311
ROLLING CODE FAILURE...............................................311
SERIAL LINK EXTERNAL FAULT..........................................311
TRANSPONDER COMMUNICATION FAILURE..............................313
TRANSPONDER ID MISMATCH..........................................313
TRANSPONDER RESPONSE MISMATCH..................................313
VIN MISMATCH........................................................315
VERIFICATION TESTS
VERIFICATION TESTS..................................................317
8.0 COMPONENT LOCATIONS..............................................323
8.1CONTROL MODULES AND PDC.....................................323
8.2CONTROLS & SOLENOIDS.........................................323
8.3DATA LINK CONNECTOR..........................................327
8.4SENSORS.......................................................327
8.5FUEL SYSTEM...................................................330
8.6SWITCHES......................................................331
8.7SPECIFICATIONS.................................................332
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TABLE OF CONTENTS - Continued
9.0 CONNECTOR PINOUTS................................................333
A/C COMPRESSOR CLUTCH - BLACK 2 WAY..............................333
AMBIENT TEMPERATURE SENSOR - GRAY 2 WAY.........................333
AMBIENT TEMPERATURE SENSOR (SENSOR SIDE) 2 WAY..................333
BRAKE LAMP SWITCH - GRAY 6 WAY....................................333
BRAKE SHIFT INTERLOCK SOLENOID (EXCEPT BUILT-UP EXPORT)-2WAY ..334
CAMSHAFT POSITION SENSOR - BLACK 3-WAY...........................334
CLOCKSPRING C1 - YELLOW 2 WAY.....................................334
CLOCKSPRING C2 - NATURAL 5 WAY....................................334
CLOCKSPRING C3 - BLACK 2 WAY.......................................335
CLUTCH INTERLOCK SWITCH (MTX) - BLACK 2 WAY.......................335
CLUTCH INTERLOCK SWITCH JUMPER (EATX) - BLACK 2 WAY..............335
CRANKSHAFT POSITION SENSOR - BLACK 3 WAY.........................335
DATA LINK CONNECTOR - BLACK 16 WAY................................336
EGR SOLENOID - GRAY 2 WAY..........................................336
ENGINE COOLANT TEMPERATURE SENSOR - BLACK 2 WAY................336
ENGINE OIL PRESSURE SWITCH - GREEN 2 WAY.........................336
EVAP/PURGE SOLENOID - BLACK 2 WAY.................................337
DUTY CYCLE EVAP/PURGE SOLENOID...................................337
FUEL INJECTOR NO. 1 (2.0L/2.4L) - BLACK 2 WAY..........................337
FUEL INJECTOR NO. 1 (3.3L/3.8L) - BLACK 2 WAY..........................338
FUEL INJECTOR NO. 2 (2.OL/2.4L) - BLACK 2 WAY.........................338
FUEL INJECTOR NO. 2 (3.3L/3.8L) - BLACK 2 WAY..........................338
FUEL INJECTOR NO. 3 (3.3L/3.8L)- BLACK 2 WAY..........................338
FUEL INJECTOR NO. 3 (2.0L/2.4L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 4 (3.3L/3.8L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 4 (2.0L/2.4L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 5 (3.3L/3.8L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 6 (3.3L/3.8L) - BLACK 2 WAY..........................340
FUEL TANK MODULE - LIGHT GRAY 4 WAY...............................340
GENERATOR (GENERATOR SIDE).......................................340
GENERATOR - BLACK 3 WAY...........................................340
IDLE AIR CONTROL MOTOR - BLACK 4 WAY..............................341
IGNITION COIL PACK (2.0L/2.4L) - BLACK 3 WAY...........................341
IGNITION COIL PACK (3.3L/3.8L) - BLACK 4 WAY...........................341
INSTRUMENT CLUSTER - BLACK 13 WAY.................................341
INTAKE AIR TEMPERATURE/MANIFOLD ABSOLUTE PRESSURE SENSOR (2.0L) -
GRAY4 WAY..........................................................342
INTAKE AIR TEMPERATURE SENSOR (2.4L) - GRAY 2 WAY..................342
KNOCK SENSOR - GRAY 2 WAY.........................................342
LEAK DETECTION PUMP - LT. GRAY 4 WAY...............................342
MANIFOLD ABSOLUTE PRESSURE SENSOR (2.4L/3.3L/3.8L) - BLACK 3 WAY. . .343
OUTPUT SPEED SENSOR - GRAY 2 WAY.................................343
OXYGEN SENSOR (SENSOR SIDE)......................................343
OXYGEN SENSOR 1/1 UPSTREAM - GRAY 4 WAY..........................343
OXYGEN SENSOR 1/2 DOWNSTREAM - BLACK 4 WAY.....................344
PARK/NEUTRAL POSITION SWITCH (ATX) - BLACK 3 WAY...................344
FUSES...............................................................346
A/C COMPRESSOR CLUTCH RELAY......................................346
AUTOMATIC SHUT DOWN RELAY (GAS)..................................346
CIGAR LIGHTER/ACCESSORY RELAY....................................346
DIESEL POWER RELAY................................................347
v
ProCarManuals.com

CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING O2S HEATER
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING ENGINE ME-
CHANICAL SYSTEMS
CHECKING EVAP EMISSION
SYSTEM
CHECKING EGR SYSTEM
CHECKING IAT SENSOR
CHECKING PNP SWITCH
3.4 USING THE DRBIIIT
Refer to the DRBIIItuser 's guide for instructions
and assistance with reading trouble codes, erasing
trouble codes, and other DRBIIItfunctions.
3.5 DRB ERROR MESSAGES AND BLANK
SCREEN
Under normal operation, the DRBIIItwill dis-
play one of only two error messages:
± User-Requested WARM Boot or User-
Requested COLD Boot.
This is a sample of such an error message display:
ver: 2.14
date: 26 Jul93
file: key_itf.cc
date: Jul 26 1993
line: 548
err: 0x1
User-Requested COLD Boot
Press MORE to switch between this display
and the application screen.
Press F4 when done noting information.
3.5.1 DRB IIITDOES NOT POWER UP
If the LED's do not light or no sound is emitted at
start up, check for loose cable connections or a bad
cable. Check the vehicle battery voltage (data link
connector cavity 16). A minimum of 11 volts is
required to adequately power the DRBIIIt.
If all connections are proper between the
DRBIIItand vehicle or other devices, and the
vehicle battery is fully charged, an inoperative
DRBIIItmay be the result of a faulty cable or
vehicle wiring. For a blank screen, refer to the
appropriate body diagnostics manual.
3.5.2 DISPLAY IS NOT VISIBLE
Low temperatures will affect the visibility of the
display. Adjust the contrast to compensate for this
condition.
4.0 DISCLAIMERS, SAFETY,
WARNINGS
4.1 DISCLAIMERS
All information, illustrations, and specifications
contained in this manual are based on the latest
information available at the time of publication.
The right is reserved to make changes at any time
without notice.
4.2 SAFETY
4.2.1 TECHNICIAN SAFETY INFORMATION
WARNING: ENGINES PRODUCE CARBON
MONOXIDE THAT IS ODORLESS, CAUSES
SLOWER REACTION TIME, AND CAN LEAD
TO SERIOUS INJURY. WHEN THE ENGINE IS
OPERATING, KEEP SERVICE AREAS WELL
VENTILATED OR ATTACH THE VEHICLE
EXHAUST SYSTEM TO THE SHOP EXHAUST
REMOVAL SYSTEM.
Set the parking brake and block the wheels before
testing or repairing the vehicle. It is especially impor-
tant to block the wheels on front-wheel drive vehicles;
the parking brake does not hold the drive wheels.
When servicing a vehicle, always wear eye pro-
tection, and remove any metal jewelry such as
watchbands or bracelets that might make an inad-
vertent electrical contact.
When diagnosing a powertrain system problem,
it is important to follow approved procedures where
11
GENERAL INFORMATION
ProCarManuals.com

4.3.3 ELECTRONIC PINION FACTOR
WARNING
The pinion factor must be set for all new trans-
mission control modules. If the pinion factor is not
set or if it is set incorrectly, any speed-related
accessories will not operate or will operate inaccu-
rately. This includes the speedometer, speed con-
trol, rolling door locks, and other devices that are
operated by the powertrain and body control mod-
ules. For instructions on setting the pinion factor,
see the appropriate transmission diagnostic man-
ual or the service manual.
5.0 RECOMMENDED TOOLS
AND EQUIPMENT
DRBIIIt(diagnostic readout box) scan tool
fuel pressure adapter (C-6631) or #6539
fuel pressure kit (C-4799-B) or #5069
fuel release hose (C-4799-1)
MinAir flow fitting #6457
jumper wires
ohmmeter
oscilloscope
vacuum gauge
voltmeter
12 volt test light minimum 25 ohms resistance
with probe #8382
CAUTION: A 12 VOLT TEST LIGHT SHOULD
NOT BE USED FOR THE FOLLOWING
CIRCUITS, DAMAGE TO THE POWERTRAIN
CONTROLLER WILL OCCUR.
²5 Volt Supply
²8 Volt Supply
²J1850 PCI Bus
²CCD Bus
²CKP Sensor Signal
²CMP Sensor Signal
²Vehicle Speed Sensor Signal
²O2 Sensor Signal
6.0 GLOSSARY OF TERMS
ABSantilock brake system
backfire,
popbackfuel ignites in either the intake or
the exhaust system
CKPcrank position sensor
CMPcamshaft position sensor
cuts out,
missesa steady pulsation or the inability of
the engine to maintain a consistent
rpmDLCdata link connector (previously
called ªengine diagnostic connectorº)
detona-
tion,
spark
knocka mild to severe ping, especially un-
der loaded engine conditions
ECTengine coolant temperature sensor
EGRexhaust gas recirculation valve and
system
genera-
torpreviously called ªalternatorº
hard
startThe engine takes longer than usual
to start, even though it is able to
crank normally.
hesita-
tion, sag,
stumble
There is a momentary lack of response
when the throttle is opened.
This can
occur at all vehicle speeds. If it is se-
vere enough, the engine may stall.
IATintake air temperature sensor
IACidle air control valve
JTECCombined engine and transmission
control module
lack of
power,
sluggish
The engine has less than expected
power, with little or no increase in vehi-
cle speed when the throttle is opened.
LDPLeak Detection Pump
MAPmanifold absolute pressure sensor
MILmalfunction indicator lamp
MTVmanifold tuning valve
O2Soxygen sensor
PCIProgrammable Communication In-
terface
PCMpowertrain control module
PCMpowertrain control module
PCVpositive crankcase ventilation
PEPPeripheral Expansion Port
poor fuel
economyThere is significantly less fuel mile-
age than other vehicles of the same
design and configuration
rough,
unstable,
or er-
ratic idle
stallingThe engine runs unevenly at idle
and causes the engine to shake if it
is severe enough. The engine idle
rpm may vary (called ªhuntingº).
This condition may cause stalling if
it is severe enough.
SKIMSentry Key Immobilizer Module
SKISSentry Key Immobilizer System
start and
stallThe engine starts but immediately
dies.
13
GENERAL INFORMATION
ProCarManuals.com

TEST ACTION APPLICABILITY
11 Check for any of the following conditions/mechanical problems.
ENGINE VACUUM Ð must be at least 13 inches in neutral
ENGINE VALVE TIMING Ð must be within specifications
ENGINE COMPRESSION Ð must be within specifications
ENGINE EXHAUST SYSTEM Ð must be free of any restrictions or leaks
ENGINE PVC SYSTEM Ð must flow freely
TORQUE CONVERTER STALL SPEED Ð must be within specifications
POWER BRAKE BOOSTER Ð no internal vacuum leaks
FUEL- must be free of contamination
FUEL INJECTOR Ð plugged or restricted injector; control wire not connected to
correct injector.
Are there any engine mechanical problems?All
Ye s®Repair as necessary.
Perform FUEL SYSTEM/MISFIRE MONITOR VERIFICATION
TEST
No®Go To 12
12 Turn ignition off.
Warning: The fuel system is under constant pressure (even with the engine
off). Before testing or servicing any fuel system hose, fitting or line, the fuel
system pressure must be released.
Disconnect the fuel supply line at the fuel rail.
Connect fuel line adapter #6539(5/169) or #6631 (3/89) to the disconnected fuel supply
line. Insert the other end of the adapter into a graduated container.
Caution: Do not operate the fuel pump for more than 7 seconds in the next
step. Fuel pump module reservoir may run empty and damage to the fuel
pump may result.
Specification: A good fuel pump will deliver at least 1/4 liter of fuel in 7
seconds.
With the DRB, actuate the ASD Fuel System test for 7 seconds.
Is the fuel pump capacity within specification?All
Ye s®Test Complete.
No®Check for a kinked/damaged fuel supply line between the fuel
tank and fuel rail. If OK, replace the fuel filter/pressure regulator.
Caution: Stop ALL Actuations.
13 The conditions required to set the DTC are no longer present.
With the DRB read and record the freeze frame data and the ªFuel System Similar
Conditions Windowº data.
Utilize the data and try to duplicate the operating conditions at which the DTC was
set. Pay particular attention to the ECT and RPM for added diagnostics.
Note: Refer to any TSB's that may apply to the symptom.
Test Complete
Repair
Test Complete.
78
DRIVEABILITY
P-0171±1/1 FUEL SYSTEM LEAN ÐContinued
ProCarManuals.com

TEST ACTION APPLICABILITY
8 Turn ignition off.
Warning: The fuel system is under a constant pressure (even with the engine
off). Before testing or servicing any fuel system hose, fitting or line, the fuel
system pressure must be released.
Remove the pressure test port cap at the fuel rail test port. Connect a fuel pressure
gauge to the test port pressure fitting on the fuel rail.
Ignition on. With the DRB, actuate the ASD Fuel System test and observe the fuel
pressure gauge.
Note: Fuel pressure specification is 49.2 psi +/þ 5 psi.
Choose a conclusion that best matches your fuel pressure reading.All
Below Specification
Go To 9
Within Specification
Go To 13
Above Specification
Replace the fuel filter/pressure regulator.
Caution: Stop ALL Actuations.
9 Check for any of the following conditions/mechanical problems.
ENGINE VACUUM Ð must be at least 13 inches in neutral
ENGINE VALVE TIMING Ð must be within specifications
ENGINE COMPRESSION Ð must be within specifications
ENGINE EXHAUST SYSTEM Ð must be free of any restrictions or leaks.
ENGINE PVC SYSTEM Ð must flow freely
TORQUE CONVERTER STALL SPEED Ð must be within specifications
POWER BRAKE BOOSTER Ð no internal vacuum leaks
FUEL - must be free of contamination
FUEL INJECTOR Ð plugged or restricted injector; control wire not connected to
correct injector
Are there any engine mechanical problems?All
Ye s®Repair as necessary.
Perform FUEL SYSTEM/MISFIRE MONITOR VERIFICATION
TEST
No®Go To 10
10 Turn ignition off.
Warning: The fuel system is under a constant pressure (even with the engine
off). Before testing or servicing any fuel system hose, fitting or line, the fuel
system pressure must be released.
Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.
Install special 5/169fuel line adapter tool #6539 between disconnected fuel line and
the fuel pump module.
Attach a fuel pressure test gauge to the ªT'' fitting on tool #6539.
Ignition on. With the DRB, actuate the ASD Fuel System test and observe the fuel
pressure gauge.
Note: Fuel pressure specification is 49.2 psi +/- 5 psi.
Is the fuel pressure within specification now?All
Ye s®Repair the restriction in the chassis fuel supply line between the
fuel tank and fuel rail.
No®Go to 11
Caution: Stop ALL Actuations.
81
P0172 -1/1 FUEL SYSTEM RICH ÐContinued
ProCarManuals.com

TEST ACTION APPLICABILITY
11Warning: The fuel system is under a constant pressure (even with the engine
off). Before testing or servicing any fuel system hose, fitting or line, the fuel
system pressure must be released.
Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.
Is the Fuel Inlet Strainer plugged?All
Ye s®Replace the Fuel Inlet Strainer.
No®Go To 12
12 If there are no potential causes remaining, the Fuel Pump Module is assumed to be
defective.
View repair options.All
Repair
Replace the Fuel Pump Module
13 Check for any of the following conditions/mechanical problems.
ENGINE VACUUM Ð must be at least 13 inches in neutral
ENGINE VALVE TIMING Ð must be within specifications
ENGINE COMPRESSION Ð must be within specifications
ENGINE EXHAUST SYSTEM Ð must be free of any restrictions or leaks.
ENGINE PVC SYSTEM Ð must flow freely
TORQUE CONVERTER STALL SPEED Ð must be within specifications
POWER BRAKE BOOSTER Ð no internal vacuum leaks
FUEL - must be free of contamination
FUEL INJECTOR Ð plugged or restricted injector; control wire not connected to
correct injector
Are there any engine mechanical problems?All
Ye s®Repair as necessary.
Perform FUEL SYSTEM/MISFIRE MONITOR VERIFICATION
TEST
No®Test Complete.
14 The conditions required to set the DTC are no longer present.
With the DRB read and record the freeze frame data and the ªFuel System Similar
Conditions Window'' data.
Utilize the data and try to duplicate the operating conditions at which the DTC was
set. Pay particular attention to the ECT and RPM for added diagnostics.
Note: Refer to any TSB's that may apply to the symptom.
Test Complete
Repair
Test Complete.
82
P0172 -1/1 FUEL SYSTEM RICH ÐContinued
ProCarManuals.com