TABLE OF CONTENTS - Continued
AMBIENT TEMPERATURE SENSOR - BLACK 2 WAY........................291
AMBIENT TEMPERATURE SENSOR (SENSOR SIDE)-2WAY................292
BRAKE LAMP SWITCH - BLACK 6 WAY...................................292
BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID - BLACK 2 WAY.......292
CAMSHAFT POSITION SENSOR - BLACK 3 WAY...........................292
CLOCKSPRING C1 - WHITE 6 WAY.......................................292
CRANKSHAFT POSITION SENSOR - BLACK 3 WAY.........................293
DATA LINK CONNECTOR - WHITE 16 WAY................................293
DIAGNOSTIC JUNCTION PORT - BLACK 16 WAY...........................293
EGR SOLENOID - GRAY 2 WAY..........................................294
ENGINE COOLANT TEMPERATURE SENSOR - BLACK 2 WAY................294
ENGINE OIL PRESSURE SWITCH - LT. GREEN 2 WAY......................294
EVAP/PURGE SOLENOID - BLACK 2 WAY.................................294
FUEL INJECTOR NO. 1 - BLACK 2 WAY...................................295
FUEL INJECTOR NO. 2 - BLACK 2 WAY...................................295
FUEL INJECTOR NO. 3 - BLACK 2 WAY...................................295
FUEL INJECTOR NO. 4 - BLACK 2 WAY...................................295
FUEL INJECTOR NO. 5 (3.3L/3.8L) - BLACK 2 WAY..........................296
FUEL INJECTOR NO. 6 (3.3L/3.8L) - BLACK 2 WAY..........................296
FUEL TANK MODULE - LT. GRAY 4 WAY...................................296
GENERATOR - BLACK 2 WAY...........................................296
GENERATOR (GENERATOR SIDE).......................................297
MANIFOLD ABSOLUTE PRESSURE SENSOR - BLACK 3 WAY................297
OXYGEN SENSOR 1/1 UPSTREAM - BLACK 4 WAY.........................297
OXYGEN SENSOR 1/2 DOWNSTREAM - BLACK 4 WAY.....................297
FUSES (IPM)..........................................................299
A/C COMPRESSOR CLUTCH RELAY......................................299
ACCESSORY RELAY...................................................299
AUTOMATIC SHUTDOWN RELAY........................................300
ENGINE STARTER MOTOR RELAY.......................................300
FUEL PUMP RELAY....................................................300
POSITIVE TEMPERATURE COEFFICIENTS................................300
TRANSMISSION SAFETY SHUTDOWN RELAY.............................300
POWERTRAIN CONTROL MODULE C1 - GRAY/BLACK 40 WAY...............301
POWERTRAIN CONTROL MODULE C2 - GRAY/GRAY 40 WAY................302
10.0 SCHEMATIC DIAGRAMS................................................303
10.12001 RG 2.4L....................................................303
10.22001 RG 3.3L/3.8L................................................304
11.0 CHARTS AND GRAPHS................................................305
11.1SPECIFICATION..................................................305
v
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. Battery temperature is
determined from IAT. 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 terminal
(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 off.
LEAK DETECTION PUMP SYSTEM (IF EQUIPPED)
The leak detection pump is a device that pressur-
izes the evaporative system to determine if there
are any leaks. When certain conditions are met, the
PCM will activate the pump and start counting
pump strokes. If the pump stops within a calibrated
number of strokes, the system is determined to be
normal. If the pump does not stop or stops too soon,
a DTC will be set.
3.2.4 PCM OPERATING MODES
As input signals to the PCM change, the PCM
adjusts its response to output devices. For example,
the PCM must calculate 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.
Inopen loopoperation, the PCM receives input
signals and responds according to preset program-
ming. Inputs from the heated oxygen sensors are
not monitored.Inclosed loopoperation, 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 to
achieve 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 on position and the engine
is not running (zero rpm), the auto shutdown 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 ModeÐ 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 camshaft position has been
determined, the PCM energizes the fuel injectors
in sequence. The PCM adjusts the injector 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.
4
GENERAL INFORMATION
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
The PCM determines the spark advance based on
the following:
± engine coolant temperature
± crankshaft position
± intake air temperature
± manifold absolute pressure
± throttle position
Engine Warm-Up Modeþ 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.
Cruise or Idle Modeþ When the engine is at
normal operating temperature, this is a closed loop
mode.
Acceleration Modeþ 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.
Decelerationþ 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 Modeþ 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 20 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 couldcause an oxygen sensor, fuel system, or misfire
monitor trouble code to be stored in the PCM.
Engine Timingþ The PCM cannot detect an
incorrectly indexed timing chain, camshaft
sprocket, or crankshaft sprocket. The PCM also
cannot detect an incorrectly indexed distributor.(*)
Fuel Pressureþ Fuel pressure is controlled by
the fuel pressure regulator. The PCM cannot detect
a clogged fuel pump inlet filter, clogged in-line filter,
or a pinched fuel supply.(*)
Fuel Injectorsþ The PCM cannot detect if a fuel
injector is clogged, the pintle is sticking, or the
wrong injectors are installed.(*)
Fuel Requirementsþ 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 Groundsþ 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 Flowþ The PCM cannot
detect a clogged or restricted air cleaner inlet or
filter element.(*)
Exhaust Systemþ The PCM cannot detect a
plugged, restricted, or leaking exhaust system.(*)
Cylinder Compressionþ The PCM cannot de-
tect uneven, low, or high engine cylinder compres-
sion.(*)
Excessive Oil Consumptionþ 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
designed to prevent unauthorized vehicle opera-
tion. The system consists of a Sentry Key Immobi-
lizer Module (SKIM), ignition key(s) equipped with
a transponder chip and PCM. When the ignition
switch is turned on, the SKIM interrogates the
ignition key. If the ignition key is Valid or Invalid,
the SKIM sends a PCI Bus message to the PCM
indicating ignition key status. Upon receiving this
5
GENERAL INFORMATION
message the PCM will terminate engine operation,
or 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
PCI Bus messages. This monitoring is called On
Board Diagnosis.
Certain criteria must be met for a diagnostic
trouble code to be entered into the SKIM memory.
The criteria may be a range of; Input voltage, PCI
Bus message, or coded messages to the SKIM. If all
of the criteria for monitoring a circuit or function
are met and a fault is sensed, a diagnostic trouble
code will be stored in the SKIM memory.
3.2.8 SKIS OPERATION
When ignition power is supplied to the SKIM, the
SKIM performs an internal self-test. After the self-
test is completed, the SKIM energizes the antenna
(this activates the transponder chip) and sends a
challenge to the transponder chip. The transponder
chip responds to the challenge by generating an
encrypted response message using the following:
Secret Key -This is an electronically stored
value (identification number) that is unique to each
SKIS. The secret key is stored in the SKIM, PCM
and all ignition key transponders.
Challenge- This is a random number that is
generated by the SKIM at each ignition key cycle.
The secret key and challenge are the two vari-
ables used in the algorithm that produces the
encrypted response message. The transponder uses
the crypto algorithm to receive, decode and respond
to the message sent by the SKIM. After responding
to the coded message, the transponder sends a
transponder I.D. message to the SKIM. The SKIM
compares the transponder I.D. to the available valid
key codes in the SKIM memory (8 key maximum at
any one time). After validating the key ignition the
SKIM sends a PCI Bus message called a Seed
Request to the engine controller then waits for a
PCM response. If the PCM does not respond, the
SKIM will send the seed request again. After three
failed attempts the SKIM will stop sending the seed
request and store a trouble code. If the PCM sends
a seed response, the SKIM sends a valid/invalid key
message to the PCM. This is an encrypted message
that is generated using the following:
VIN -Vehicle Identification Number
Seed -This is a random number that is generated
by the PCM at each ignition key cycle.
The VIN and seed are the two variables used in
the rolling code algorithm that encrypts the valid/
invalid key message. The PCM uses the rolling code
algorithm to receive, decode and respond to the
valid/invalid key message sent by the SKIM. Aftersending the valid/invalid key message the SKIM
waits 3.5 seconds for a PCM status message from
the PCM. If the PCM does not respond with a valid
key message to the SKIM, a fault is detected and a
trouble code is stored.
The SKIS incorporates a VTSS LED located on
the instrument panel upper cover. The LED re-
ceives switched ignition voltage and is hardwired to
the body control module. The LED is actuated when
the SKIM sends a PCI Bus message to the body
controller requesting the LED on. The body control-
ler then provides the ground for the LED. The
SKIM will request VTSS LED operation for the
following:
± bulb checks at ignition on
± to alert the vehicle operator to a SKIS mal-
function
± customer key programming mode
For all faults except transponder faults and VTSS
LED remains on steady. In the event of a transpon-
der fault the LED flashes at a rate of 1 Hz (once per
second). If a fault is present the LED will remain on
or flashing for the complete ignition cycle. If a fault
is stored in SKIM memory which prevents the
system from operating properly, the PCM will allow
the engine to start and run (for 2 seconds) up to six
times. After the sixth attempt, the PCM disables
the starter relay until the fault is corrected.
3.2.9 PROGRAMMING THE POWERTRAIN
CONTROL MODULE
Important Note:Before replacing the PCM for a
failed driver, control circuit or ground circuit, be
sure to check the related component/circuit integ-
rity for failures not detected due to a double fault in
the circuit. Most PCM driver/control circuit failures
are caused by internal failure to components (i.e.
12-volt pull-ups, drivers and ground sensors). These
failures are difficult to detect when a double fault
has occurred and only one DTC has set.
NOTE: IF THE PCM AND THE SKIM ARE
REPLACED AT THE SAME TIME, PROGRAM
THE VIN INTO THE PCM FIRST. ALL VEHICLE
KEYS WILL THEN NEED TO BE REPLACED
AND PROGRAMMED TO THE NEW SKIM.
The SKIS Secret Key is an I.D. code that is
unique to each SKIS. This code is programmed and
stored in the SKIM, engine controller and transpon-
der chip (ignition key). When replacing the PCM it
is necessary to program the secret key into the
PCM.
1. Turn the ignition on (transmission in park/
neutral).
2. Use the DRB and select THEFT ALARM, SKIM
then MISCELLANEOUS.
6
GENERAL INFORMATION
Symptom:
P0622-GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored and Set Condition:
P0622-GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored: With the ignition on. Engine running.
Set Condition: When the PCM tries to regulate the generator field with no result during
monitoring.
POSSIBLE CAUSES
WIRING HARNESS INTERMITTENT
INSPECT WIRING HARNESS
ASD RELAY OUTPUT CIRCUIT OPEN
GENERATOR FIELD DRIVER CIRCUIT SHORTED TO GROUND
GENERATOR FIELD DRIVER CIRCUIT OPEN
GENERATOR
POWERTRAIN CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, actuate the Generator Field Driver circuit.
Using a 12-volt test light connected to ground, backprobe the Generator Field Driver
circuit in the back of the Generator.
Does the test light illuminate brightly and flash?All
Ye s®Go To 2
No®Go To 4
2 Turn the ignition on.
With the DRBIIItactuate the Generator Field Driver circuit.
Wiggle the wiring harness from the Generator to PCM.
With the DRBIIIt, read DTC's.
Did the DTC reset?All
Ye s®Repair as necessary .
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 3
3 Turn the ignition off.
Using the schematic as a guide, inspect the Wiring and Connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Test Complete.
16
CHARGING
TEST ACTION APPLICABILITY
4NOTE: Carefully inspect all Connectors for corrosion or spread Terminals
before continuing.
Disconnect the Generator Field harness connector.
Turn the ignition on.
With the DRBIIItactuate the Generator Field Driver circuit.
Using a 12-volt test light connected to ground, probe the ASD Relay Output circuit.
Does the test light illuminate brightly?All
Ye s®Go To 5
No®Repair the ASD Relay Output circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
5 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the Generator Field harness connector.
Measure the resistance of the Generator Field Driver circuit from PCM harness
connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Generator Field Driver circuit for a shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 6
6 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the Generator Field harness connector.
Measure the resistance of the Generator Field Driver circuit from the PCM harness
connector to the Generator Field harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 7
No®Repair the Generator Field Driver circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
7 Turn the ignition off.
Disconnect the Generator Field harness connector.
Measure the resistance across the Generator Field Terminals at the Generator.
Is the resistance below 5.0 ohms?All
Ye s®Repair or replace the Generator as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 8
8 If there is no more possible causes remaining, view repair. All
Repair
Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
17
CHARGING
P0622-GENERATOR FIELD NOT SWITCHING PROPERLY ÐContinued
Symptom:
P1682-CHARGING SYSTEM VOLTAGE TOO LOW
When Monitored and Set Condition:
P1682-CHARGING SYSTEM VOLTAGE TOO LOW
When Monitored: With the ignition on. Engine RPM greater than 1152 RPM. With no
other charging system codes set.
Set Condition: The battery sensed voltage is 1 volt below the charging goal for 13.47
seconds. The PCM senses the battery voltage turns off the field driver and senses the
battery voltage again. If the voltages are the same, the code is set.
POSSIBLE CAUSES
BATTERY TEMPERATURE
B+ CIRCUIT HIGH RESISTANCE
GENERATOR GROUND HIGH RESISTANCE
INTERMITTENT CONDITION
GENERATOR FIELD DRIVER CIRCUIT OPEN
ASD RELAY OUTPUT CIRCUIT OPEN
GENERATOR
TEST ACTION APPLICABILITY
1NOTE: Inspect the vehicle for aftermarket accessories that may exceed the
Generator System output.
Turn the ignition off.
NOTE: The battery must be fully charged.
NOTE: The Generator belt tension and condition must be checked before
continuing.
Start the engine.
Allow the idle to stabilize.
With the DRBIIIt, read the Target Charging Voltage.
Is the Target Charging Voltage above 15.1 volts?All
Ye s®Go To 2
No®Go To 3
20
CHARGING
TEST ACTION APPLICABILITY
6 Disconnect the Generator Field harness connector.
Turn the ignition on.
With the DRBIIItactuate the Generator Field Driver.
Using a 12-volt test light connected to ground, probe the ASD Relay Output circuit.
Does the test light illuminate brightly?All
Ye s®Go To 7
No®Repair the ASD Relay Output circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
7 If there is no possible causes remaining, view repair. All
Ye s®Repair or replace the Generator as necessary..
Perform POWERTRAIN VERIFICATION TEST VER - 3.
8WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Test Complete.
22
CHARGING
P1682-CHARGING SYSTEM VOLTAGE TOO LOW ÐContinued