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
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3.2.3 OTHER CONTROLS
CHARGING SYSTEM
The charging system is turned on when the
engine is started and ASD relay energized. When
the ASD relay is on, ASD output voltage is supplied
to the ASD sense circuit at the PCM. This voltage is
connected in some cases, through the PCM and
supplied to one of the generator field terminals
(Gen Source +). All others, the Gen field is con-
nected directly to the ASD output voltage. The
amount of current produced by the generator is
controlled by the Electronic Voltage Regulator
(EVR) circuitry, in the PCM. A battery temperature
sensor, located either in the battery tray, using the
ambient sensor, or in the PCM itself, is used to
sense battery temperature. This temperature along
with sensed line voltage, is used by the PCM to vary
the battery charging rate. This is done by cycling
the ground path to the other generator field termi-
nal (Gen field driver).
SPEED CONTROL SYSTEM
The PCM controls vehicle speed by operation of
the speed control servo vacuum and vent solenoids.
Energizing the vacuum solenoid applies vacuum to
the servo to increase throttle position. Operation of
the vent solenoid slowly releases the vacuum allow-
ing throttle position to decrease. A special dump
solenoid allows immediate release of throttle posi-
tion caused by braking, cruise control switch turned
off, shifting into neutral, excessive RPM (tires spin-
ning) or ignition key off.
3.2.4 PCM OPERATING MODES
As input signals to the powertrain control module
(PCM) change, the PCM adjusts its response to
output devices. For example, the PCM must calcu-
late a different injector pulse width and ignition
timing for idle than it does for wide open throttle.
There are several different modes of operation that
determine how the PCM responds to the various
input signals.
There are two types of engine control operation:
open loopandclosed loop.
In open loop operation, the PCM receives input
signals and responds according to preset program-
ming. Inputs from the heated oxygen sensors are
not monitored.
In closed loop operation, the PCM monitors the
inputs from the heated oxygen sensors. This input
indicates to the PCM whether or not the calculated
injector pulse width results in the ideal air-fuel
ratio of 14.7 parts air to 1 part fuel. By monitoring
the exhaust oxygen content through the oxygen
sensor, the PCM can fine tune injector pulse width.
Fine tuning injector pulse width allows the PCM toachieve the lowest emission levels while maintain-
ing optimum fuel economy.
The engine start-up (crank), engine warm-up,
and wide open throttle modes are open loop modes.
Under most operating conditions, closed loop modes
occur with the engine at operating temperature.
IGNITION SWITCH ON (ENGINE OFF) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
1. The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic
fuel strategy.
2. The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input.
The PCM modifies fuel strategy based on this
input.
When the key is in the ªonº position and the
engine is not running (zero rpm), the auto shut-
down relay and fuel pump relay are not energized.
Therefore, voltage is not supplied to the fuel pump,
ignition coil, and fuel injectors.
Engine Start-up Mode -This is an open loop
mode. The following actions occur when the starter
motor is engaged:
1. The auto shutdown and fuel pump relays are
energized. If the PCM does not receive the cam-
shaft and crankshaft signal within approxi-
mately one second, these relays are de-
energized.
2. The PCM energizes all fuel injectors until it
determines crankshaft position from the cam-
shaft and crankshaft signals. The PCM deter-
mines crankshaft position within one engine
revolution. After the crankshaft position has
been determined, the PCM energizes the fuel
injectors in sequence. The PCM adjusts the in-
jector pulse width and synchronizes the fuel
injectors by controlling the fuel injectors' ground
paths.
3. Once the engine idles within 64 rpm of its target
engine speed, the PCM compares the current
MAP sensor value with the value received dur-
ing the ignition switch on (zero rpm) mode. A
diagnostic trouble code is written to PCM mem-
ory if a minimum difference between the two
values is not found.
Once the auto shutdown and fuel pump relays
have been energized, the PCM determines the fuel
injector pulse width based on the following:
± engine coolant temperature
± manifold absolute pressure
± intake air temperature
± engine revolutions
± throttle position
4
GENERAL INFORMATION
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The PCM determines the spark advance based on
the following:
± engine coolant temperature
± crankshaft position
± camshaft position
± intake air temperature
± manifold absolute pressure
± throttle position
Engine Warm-Up Mode -This is an open loop-
mode. The PCM adjusts injector pulse width and
controls injector synchronization by controlling the
fuel injectors' ground paths. The PCM adjusts igni-
tion timing and engine idle speed. The PCM adjusts
the idle speed by controlling the idle air control
motor and spark advance.
Cruise or Idle Mode -When the engine is at
normal operating temperature, this is a closed loop
mode.
Acceleration Mode -This is a closed loop mode.
The PCM recognizes an increase in throttle position
and a decrease in manifold vacuum as engine load
increases. In response, the PCM increases the in-
jector pulse width to meet the increased load. The
A/C compressor may be de-energized for a short
period of time.
Deceleration -This is a closed loop mode. The
PCM recognizes a decrease in throttle position and
an increase in manifold vacuum as engine load
decreases. In response, the PCM decreases the
injector pulse width to meet the decreased load.
Full injector shut off may be obtained during high
speed deceleration.
Wide Open Throttle Mode -This is an open
loop mode. The throttle position sensor notifies the
PCM of a wide open throttle condition. Once a wide
open throttle is sensed, the PCM de-energizes the
A/C compressor clutch relay for 15 seconds.
3.2.5 NON-MONITORED CIRCUITS
The PCM does not monitor the following circuits,
systems, and conditions even though they could
have malfunctions that result in driveability prob-
lems. A diagnostic code may not be displayed for the
following conditions. However, problems with these
systems may cause a diagnostic code to be displayed
for other systems. For example, a fuel pressure
problem will not register a diagnostic code directly,
but could cause a rich or lean condition. This could
cause an oxygen sensor, fuel system, or misfire
monitor trouble code to be stored in the PCM.
Engine Timing -The PCM cannot detect an
incorrectly indexed timing chain, camshaft
sprocket, or crankshaft sprocket. The PCM also
cannot detect an incorrectly indexed distributor.(*)
Fuel Pressure -Fuel pressure is controlled by
the fuel pressure regulator. The PCM cannot detecta clogged fuel pump inlet filter, clogged in-line filter,
or a pinched fuel supply.(*)
Fuel Injectors -The PCM cannot detect if a fuel
injector is clogged, the pintle is sticking, or the
wrong injectors are installed.(*)
Fuel Requirements -Poor quality gasoline can
cause problems such as hard starting, stalling, and
stumble. Use of methanol-gasoline blends may re-
sult in starting and driveability problems. See indi-
vidual symptoms and their definitions in Section
6.0 (Glossary of Terms)
PCM Grounds -The PCM cannot detect a poor
system ground. However, a diagnostic trouble code
may be stored in the PCM as a result of this
condition.
Throttle Body Air Flow -The PCM cannot
detect a clogged or restricted air cleaner inlet or
filter element.(*)
Exhaust System -The PCM cannot detect a
plugged, restricted, or leaking exhaust system.(*)
Cylinder Compression -The PCM cannot de-
tect uneven, low, or high engine cylinder compres-
sion.(*)
Excessive Oil Consumption -Although the
PCM monitors the exhaust stream oxygen content
through the oxygen sensor when the system is in a
closed loop, it cannot determine excessive oil con-
sumption.
(*)NOTE: ANY OF THESE CONDITIONS
COULD RESULT IN A RICH OR LEAN
CONDITION CAUSING AN OXYGEN SENSOR
TROUBLE CODE TO BE STORED IN THE
PCM, OR THE VEHICLE MAY EXHIBIT ONE
OR MORE OF THE DRIVEABILITY
SYMPTOMS LISTED IN THE TABLE OF
CONTENTS.
3.2.6 SKIS OVERVIEW
The Sentry Key Immobilizer System (SKIS) is an
immobilizer system design to prevent unauthorized
vehicle operation. The system consists of a Sentry
Key Immobilizer Module (SKIM), ignition key(s)
equipped with a transponder chip and engine con-
troller. When the ignition switch is turned on, the
SKIM interrogates the ignition key. If the ignition
key is ``Valid'', the SKIM sends a CCD Bus message
to the engine controller indicating the presence of a
valid igntion key. Upon receiving a ``Valid'' key
signal the PCM will allow the engine to continue to
operate.
3.2.7 SKIM ON-BOARD DIAGNOSTICS
The SKIM has been programmed to transmit and
monitor many different coded messages as well as
CCD Bus messages. This monitoring is called ``On
Board Diagnosis''.
5
GENERAL INFORMATION
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TEST ACTION APPLICABILITY
3 Turn Ignition On (Engine Off).
During the following voltage drop measurement, wiggle wires between O2S Connec-
tor and PCM Connector.
Using a voltmeter, backprobe O2S (Signal) Circuit between O2S Connector (O2S
Signal) and PCM Connector (O2S Signal).
While wiggling wires, is the voltage drop reading below 0.10 VDC?All
Ye s®Go To 4
No®Repair poor connection (high resistance) on O2S Signal Circuit.
Perform VERIFICATION TEST VER-5A3.
4 At this time the 1/1 O2S SLOW RESPONSE does not exist or is an intermittent
problem.
With the DRB, read the FREEZE FRAME DATA.
With this screen, attempt to duplicate the condition that has set this fault.
While using FREEZE FRAME pay particular attention to the fault setting condi-
tions, such as speed, temp, load, and map vacuum.
Does the 1/1 O2S SLOW RESPONSE reoccur?All
Ye s®Go To 5
No®The 1/1 O2S SLOW RESPONSE no longer exists.
Perform VERIFICATION TEST VER-5A3.
5 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Start the Engine.
NOTE: Check the exhaust for excessive smoke caused by oil or coolant
consumption.
Is there an oil or coolant consumption condition present?All
Ye s®Repair engine mechanical as necessary and replace O2 Sensor.
Perform VERIFICATION TEST VER-5A3.
No®Go To 6
6 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Start the Engine.
Check the Exhaust System for leaks between the Engine and the catalyst.
Are there any leaks?All
Ye s®Repair or replace leaking Exhaust System as necessary.
Perform VERIFICATION TEST VER-5A3.
No®Go To 7
7 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Turn Ignition On (Engine Off).
Using a voltmeter, backprobe O2S (Signal) Circuit between O2S Connector (O2S
Signal) and PCM Connector (O2S Signal).
Is the voltage drop reading below 0.10 VDC?All
Ye s®Go To 8
No®Repair poor connection (high resistance) on O2S Signal Circuit.
Perform VERIFICATION TEST VER-5A3.
58
DRIVEABILITY
P-0133 1/1 O2S SLOW RESPONSE ÐContinued
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Turn Ignition On (Engine Off).
During the following voltage drop measurement, wiggle wires between O2S Connec-
tor and PCM Connector.
Using a voltmeter, backprobe O2S (Signal) Circuit between O2S Connector (O2S
Signal) and PCM Connector (O2S Signal).
While wiggling wires, is the voltage drop reading below 0.10 VDC?All
Ye s®Go To 4
No®Repair poor connection (high resistance) on O2S Signal Circuit.
Perform VERIFICATION TEST VER-5A3.
4 At this time the 1/2 O2S SLOW RESPONSE does not exist or is an intermittent
problem.
With the DRB, read the FREEZE FRAME DATA.
With this screen, attempt to duplicate the condition that has set this fault.
While using FREEZE FRAME DATA pay particular attention to the fault setting
conditions, such as speed, temp, load, and map vacuum.
Does the 1/2 O2S SLOW RESPONSE reoccur?All
Ye s®Go To 5
No®The 1/2 O2S SLOW RESPONSE no longer exists.
Perform VERIFICATION TEST VER-5A3.
5 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Start the Engine.
NOTE: Check the exhaust for excessive smoke caused by oil or coolant
consumption.
Is there an oil or coolant consumption condition present?All
Ye s®Repair engine mechanical as necessary and replace O2 Sensor.
Perform VERIFICATION TEST VER-5A3.
No®Go To 6
6 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Start the Engine.
Check the Exhaust System for leaks between the Engine and the catalyst.
Are there any leaks?All
Ye s®Repair or replace leaking Exhaust System as necessary.
Perform VERIFICATION TEST VER-5A3.
No®Go To 7
7 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Turn Ignition On (Engine Off).
Using a voltmeter, backprobe O2S (Signal) Circuit between O2S Connector (O2S
Signal) and PCM Connector (O2S Signal).
Is the voltage drop reading below 0.10 VDC?All
Ye s®Go To 8
No®Repair poor connection (high resistance) on O2S Signal Circuit.
Perform VERIFICATION TEST VER-5A3.
69
DRIVEABILITY
P-0139 1/2 O2S SLOW RESPONSE ÐContinued
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POSSIBLE CAUSES
OTHER POSSIBLE CAUSES FOR MIS-FIRE
CAM, CRANK, VALVE TIMING, OR VACUUM PROBLEM
ELECTRONIC IGNITION COIL OUTPUT LOW
ENGINE MECHANICAL PROBLEM
SECONDARY IGNITION PATTERN IRREGULAR
FUEL CONTAMINATION
FUEL PRESSURE LEAK DOWN OUT OF SPECIFICATION
FUEL PUMP AMPERAGE OUT OF SPECIFICATION
FUEL PUMP CAPACITY OUT OF SPECIFICATION
FUEL PUMP PRESSURE OUT OF SPECIFICATION
MIS-FIRE DOES NOT REOCCUR
TEST ACTION APPLICABILITY
1 With the DRB, read the DTCs.
Is the MIS-FIRE GOOD TRIP counter displayed and equal to zero?All
Ye s®Go To 2
No®Go To 3
2 At this time the conditions that set this fault are present.
With the DRB, read the FREEZE FRAME and SIMILAR CONDITIONS WINDOWS.
Attempt to operate the vehicle in the similar conditions.
When the vehicle is operating in the SIMILAR CONDITIONS WINDOW, go to the
WHICH CYLINDER IS MISFIRING screen.
Is the DRB counting mis-fires at this time?All
Ye s®Go To 4
No®Go To 3
3 At this time the mis-fire does not exist or is an intermittent problem.
With the DRB, read the FREEZE FRAME and SIMILAR CONDITIONS WINDOW.
With these screens, attempt to duplicate the condition that has set this fault.
While using FREEZE FRAME pay particular attention to the fault setting condi-
tions, such as speed, temp, load, and map vacuum.
Does the mis-fire reoccur?All
Ye s®Go To 4
No®Mis-fire no longer exists.
Perform VERIFICATION TEST VER-5A2.
4 With the DRB, read the FREEZE FRAME DATA.
Use the freeze frame data and attempt to determine the cause.
In the FREEZE FRAME, are the adaptive fuel percentages greater than +/- 15%?All
Ye s®Go To 5
No®Go To 10
101
DRIVEABILITY
P-0300 MULTIPLE CYLINDER MIS-FIRE ÐContinued
ProCarManuals.com
TEST ACTION APPLICABILITY
12 Engine Off.
Connect a suitable engine analyzer to the engine.
Allow the Engine to idle.
NOTE: If the Engine will not idle, maintain a constant RPM above idle.
NOTE: Set the scope to read display or parade pattern.
Remove any spark plug wire.
Observe the Secondary KV Line.
Is the open secondary voltage at least 25 KV?All
Ye s®Go To 13
No®Replace the Ignition Coil.
Perform VERIFICATION TEST VER-5A2.
13 Engine Off.
Connect a suitable engine analyzer to the engine.
Allow the Engine to idle.
NOTE: If the Engine will not idle, maintain a constant RPM above idle.
NOTE: Set the scope to read display or parade pattern.
Follow the equipment manufacturer's procedure for pattern analysis.
Is the secondary ignition pattern OK?All
Ye s®Go To 14
No®Repair the indicated component in the Secondary Ignition Sys-
tem.
Perform VERIFICATION TEST VER-5A2.
14 The following are possible causes for mis-fire:
Injector harness connectors, ignition coil circuit, spark plug, mechanical engine
problem, PCM power grounds, irregular cam and crank signal, injectors, restricted
exhaust, intake restriction, PCM, Evap System, EGR System, damaged trigger
wheel, and
accessory drive belts.
Do any of the above causes exist?All
Ye s®Repair as necessary.
Perform VERIFICATION TEST VER-5A2.
No®Go To 15
15The following additional items should be checked as possible mechanical
problems:
ENGINE VACUUM - must be at least 13 inches in neutral
ENGINE VALVE TIMING - must be within specifications
ENGINE COMPRESSION - must be within specifications
ENGINE EXHAUST SYSTEM - must be free of any restrictions
ENGINE PCV SYSTEM - must flow freely
ENGINE DRIVE SPROCKETS - must be properly positioned
TORQUE CONVERTER STALL SPEED - must be within specifications
POWER BRAKE BOOSTER - no internal vacuum leaks
FUEL - must be free of contamination
FUEL INJECTOR - plugged or restricted injector; control wire not connected to
correct injector
Are there any engine mechanical problems?All
Ye s®Repair as necessary.
Perform VERIFICATION TEST VER-5A2.
No®Test Complete.
103
DRIVEABILITY
P-0300 MULTIPLE CYLINDER MIS-FIRE ÐContinued
ProCarManuals.com
Symptom List:
P-0305 CYLINDER #5 MIS-FIRE
P-0306 CYLINDER #6 MIS-FIRE
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P-0305 CYLINDER #5 MIS-FIRE.
When Monitored and Set Condition:
P-0305 CYLINDER #5 MIS-FIRE
When Monitored: With the engine running, after successfully performing Crank Sensor
learn.
Set Condition: When more than a 2% misfire rate is measured during two trips, or with
a 10% to 30% misfire rate during one trip.
P-0306 CYLINDER #6 MIS-FIRE
When Monitored: With the engine running, after successfully performing Crank Sensor
learn.
Set Condition: When more than a 2% misfire rate is measured during two trips, or with
a 10% to 30% misfire rate during one trip.
POSSIBLE CAUSES
OTHER POSSIBLE CAUSES FOR MIS-FIRE
CAM, CRANK, VALVE TIMING, OR VACUUM PROBLEM
ELECTRONIC IGNITION COIL OUTPUT LOW
ENGINE MECHANICAL PROBLEM
SECONDARY IGNITION PATTERN IRREGULAR
FUEL CONTAMINATION
FUEL PRESSURE LEAK DOWN OUT OF SPECIFICATION
FUEL PUMP AMPERAGE OUT OF SPECIFICATION
FUEL PUMP CAPACITY OUT OF SPECIFICATION
FUEL PUMP PRESSURE OUT OF SPECIFICATION
MIS-FIRE DOES NOT REOCCUR
TEST ACTION APPLICABILITY
1 With the DRB, read the DTCs.
Is the MIS-FIRE GOOD TRIP counter displayed and equal to zero?ENGINE - 3.0L V6
and/or ENGINE -
3.3L V6 and/or EN-
GINE - 3.8L V6
and/or ENGINE -
3.3L V6 FFV Ye s®Go To 2
No®Go To 3
104
DRIVEABILITY
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