PARK ASSIST SYSTEM
The Park Assist System display activates an audi-
ble tone that changes from intermittent to continu-
ous as the final two Light Emitting Diodes (LED's)
are illuminated on one side or both sides of the dis-
play.
The system detection length from the rear of the
vehicle is 0.3 meters to 1.5 meters. This area extends
around the rear side of the vehicle. The system detec-
tion height from the ground is 0.2 meters to about
1.5 meters. The radio mutes when the system acti-
vates its audible tone.
When the driver selects Reverse the system scans
for objects behind the vehicle using four sensors
located in the rear bumper. A warning display above
the rear window provides both visible and audible
warnings indicating the range of the object.
The system is active only when the transmission
gear selector is in reverse for vehicle speeds less than
16 Km/h (10 mph). If the vehicle's Parking/Emer-
gency Brake is applied, the system is deactivated.
The display contains two sets of yellow and red
Light Emitting Diode's (LED's) that the driver can
see as they look over their shoulder while backing
up. Each side of the vehicle has its own warning
LED's. The system provides a visual warning by illu-
minating one or more yellow LED's as the vehicle
gets closer to the object. As the vehicle continues to
approach the object, one red LED is illuminated and
the system emits a series of short beeps. The tone
will remain constant and both red LED's are illumi-
nated once the vehicle is within 12 inches (30.5 cm)
of the object.
The system can be turned ON or OFF through the
Electronic Vehicle Information Center (EVIC) when
the vehicle is in PARK. If the park assist system is
turned OFF, a single chime will sound and the EVIC
will display the following message ªREAR PARK
ASSIST OFFº, when the vehicle is in reverse.
²Ensure that the rear bumper is free of dirt and
debris to keep the system operating properly.
²Jackhammers, large trucks, and other vibrations
could affect the performance of the system.
²Ensure that the parking brake is not applied.
If ªService Park Assist Systemº appears in the
EVIC after making sure the rear bumper is clean,
proceed to diagnose the system using a scan tool and
the appropriate diagnostic information.
WARNING
On vehicles equipped with airbags, disable
the airbag system before attempting any steer-
ing wheel, steering column, or instrument
panel component diagnosis or service. Discon-
nect and isolate the battery negative (ground)
cable, then wait two minutes for the airbag sys-
tem capacitor to discharge before performing
further diagnosis or service. This is the only
sure way to disable the airbag system. Failure
to take the proper precautions could result in
accidental airbag deployment, personal injury,
or death.
DIAGNOSIS AND TESTING - CHIME SYSTEM
Refer to the proper Body Diagnostic Procedures
manual for complete Diagnosis and Testing of the
Chime System.
NO TONE WHEN IGNITION SWITCH IS TURNED ON
AND DRIVER'S SEAT BELT IS NOT BUCKLED.
(1) Using a DRB llltscan tool, actuate chime
(BCM actuates).
(2) Using a voltmeter, check for voltage:
(a) BCM has two battery feeds at pin 1 and pin
5 of the 6±way connector.
(b) Pin 5 of the (BX2) 32 way connector of the
BCM for ignition feed.
(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to
the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, further details on
wire harness routing and retention, as well as pin-
out and location views for the various wire harness
connectors, splices and grounds.
(3) Check drivers seat belt buckle switch input
(from Occupant Restraint Controller (ORC) for a
closed circuit when not buckled. If input not seen,
look for open in wiring or switch. The switch is
grounded when belt is not buckled.
(4) Verify Programmable Communication Interface
(PCI) data bus communication between ORC and
BCM.
8B - 2 CHIME/BUZZERRS
CHIME/BUZZER (Continued)
²System diagnostics - diagnosis and error han-
dling (sensors, display, module).
²Data exchange over the Programmable Commu-
nication Interface (PCI) data bus.
OPERATION
The module has a number of functions:
²Supply voltage to the sensors and display.
²Disconnection of the display with bus idle and
over voltage Vmax.
²Triggering the sensors.
²Analyze echo delay times and calculate obstacle
distances.
²Bi-directional data communication to the display
for diagnosis.
²System diagnostics - diagnosis and error han-
dling (sensors, display, module).
²Data exchange over the Programmable Commu-
nication Interface (PCI) data bus.
The system detection length from the rear of the
vehicle is 0.3 meters to 1.5 meters. This area extends
around the rear side of the vehicle. The system detec-
tion height from the ground is 0.2 meters to about
1.5 meters. The radio mutes when the system acti-
vates its audible tone.When the driver selects Reverse, the system scans
for objects behind the vehicle using four sensors
located in the rear bumper. Objects can be detected
from up to 1.5 meters. A warning display above the
rear window provides both visible and audible warn-
ings indicating the range of the object.
The system is active only when the vehicle is in
reverse for vehicle speeds less than 16 Km/h (10
mph). If the vehicles Parking/Emergency Brake is
applied, the system is deactivated.
The display contains two sets of yellow and red
Light Emitting Diode's (LED's) that the driver can
see as they look over their shoulder while backing
up. Each side of the vehicle has its own warning
LED's. The system provides a visual warning by illu-
minating one or more yellow LED's as the vehicle
gets closer to the object. As the vehicle continues to
approaches the object, one red LED is illuminated
and the system emits a series of short beeps. The
tone will remain constant and both red LED's are
illuminated once the vehicle is within 12 inches (30.5
cm) of the object.
The system can be turned ON or OFF through the
Electronic Vehicle Information Center (EVIC) when
the vehicle is in PARK. If the park assist system is
turned OFF, a single chime will sound and the EVIC
will display the following message ªREAR PARK
ASSIST OFFº, when the vehicle is in reverse.
²Ensure that the rear bumper is free of dirt and
debris to keep the system operating properly.
²Jackhammers, large trucks, and other vibrations
could affect the performance of the system.
²Ensure that the parking brake is not applied.
If ªService Park Assist Systemº appears in the
EVIC after making sure the rear bumper is clean,
proceed to diagnose the system using a scan tool and
the appropriate diagnostic information.
To diagnose the Park Assist Module, use a scan
tool and the appropriate body diagnostic information.
REMOVAL
(1) Open hood.
(2)
Disconnect and isolate the battery negative cable.
(3) Remove the left quarter trim panel (Refer to 23
- BODY/INTERIOR/QUARTER TRIM PANEL -
REMOVAL).
Fig. 3 PARK ASSIST MODULE - LOCATION
1 - RETAINING SCREW J-CLIPS
2 - LEFT QUARTER PANEL/C-PILLAR
3 - MODULE RETAINING SCREWS
4 - PARK ASSIST MODULE
RSCHIME/BUZZER8B-5
PARK ASSIST MODULE (Continued)
(4) Disconnect the Park Assist Module electrical
connector (Fig. 4).
(5) Remove the two attaching screws and separate
the module from vehicle (Fig. 3).
INSTALLATION
(1) Position the Park Assist Module and install the
two attaching screws (Fig. 3). Torque screws to 3.5
N´m (30 in. lbs.).
(2) Connect the Park Assist Module electrical con-
nector (Fig. 4).
(3) Install the left quarter trim panel (Refer to 23 -
BODY/INTERIOR/QUARTER TRIM PANEL -
INSTALLATION).
(4) Connect the battery negative cable.
(5) Close hood.
(6) Verify vehicle and system operation.
PARK ASSIST SENSOR
DESCRIPTION
The Park Assist Sensors are located in the rear
bumper fascia mounted equally apart (Fig. 5). The
sensors generate ultrasonic pulses when triggered by
the park assist module when an obstacle is detected.
The sensors then signal the module when reflected
ultrasonic pulses are received.
The sensors detect objects with an ultrasonic pulse
that reflects off the object and then is sent to the
module to determine the distance of the object.
OPERATION
The Park Assist Sensors:
²Generate ultrasonic pulses when triggered by
the Park Assist Module.
²Reception/filtering of ultrasonic energy received.
²Signalling the module of received ultrasonic
pulses that meet threshold criteria.
The sensors are supplied power by the module. The
sensor supply is enabled when the sensor function is
necessary.
The sensors detection length from the rear of the
vehicle is 0.3 meters to 1.5 meters. This area extends
around the rear side of the vehicle. The sensor detec-
tion height from the ground is 0.2 meters to about
1.5 meters.
²Ensure that the rear bumper (sensors) is free of
dirt and debris to keep the system operating prop-
erly.
²Jackhammers, large trucks, and other vibrations
could affect the performance of the system.
²Ensure that the parking brake is not applied.
If ªService Park Assist Systemº appears in the
EVIC after making sure the rear bumper is clean,
proceed to diagnose the system using a scan tool and
the appropriate diagnostic information.
REMOVAL
(1) Open hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Remove rear fascia (Refer to 13 - FRAME &
BUMPERS/BUMPERS/REAR FASCIA - REMOVAL).
(4) Unsnap Park Assist Sensor from the retaining
housing and remove from fascia.
INSTALLATION
(1)Position the Park Assist Sensor over the retain-
ing housing and firmly snap into housing in rear fascia.
(2) Install the rear fascia (Refer to 13 - FRAME &
BUMPERS/BUMPERS/REAR FASCIA - INSTALLA-
TION).
(3) Connect the battery negative cable.
(4) Close hood.
(5) Verify vehicle and system operation.
Fig. 4 PARK ASSIST MODULE ELECTRICAL
CONNECTOR
1 - MODULE ELECTRICAL CONNECTOR
2 - PARK ASSIST MODULE
Fig. 5 PARK ASSIST SENSOR LOCATION
8B - 6 CHIME/BUZZERRS
PARK ASSIST MODULE (Continued)
ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
ELECTRONIC CONTROL MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING.......................1
BODY CONTROL MODULE
DESCRIPTION..........................2
OPERATION............................3
REMOVAL.............................4
INSTALLATION..........................4
CONTROLLER ANTILOCK BRAKE
DESCRIPTION..........................4
OPERATION............................5
REMOVAL.............................5
INSTALLATION..........................6
DATA LINK CONNECTOR
DESCRIPTION..........................6
OPERATION............................6
FRONT CONTROL MODULE
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING
FRONT CONTROL MODULE..............7
REMOVAL.............................7
INSTALLATION..........................7
HEATED SEAT MODULE
DESCRIPTION..........................8
OPERATION............................8
DIAGNOSIS AND TESTING
HEATED SEAT MODULE.................9
REMOVAL.............................9
INSTALLATION..........................9
MEMORY SEAT/MIRROR MODULE
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING
MEMORY SEAT/MIRROR MODULE.........9
REMOVAL.............................10
INSTALLATION.........................10
POWER LIFTGATE CONTROL MODULE
DESCRIPTION.........................10OPERATION...........................10
DIAGNOSIS AND TESTING
POWER LIFTGATE CONTROL MODULE....10
REMOVAL.............................10
INSTALLATION.........................11
POWERTRAIN CONTROL MODULE
DESCRIPTION
DESCRIPTION........................11
OPERATION - SENSOR RETURN - PCM
INPUT..............................14
OPERATION - DATA BUS COMMUNICATION
RECEIVE - PCM INPUT.................14
OPERATION - IGNITION SENSE - PCM
INPUT..............................14
OPERATION - PCM GROUND............14
OPERATION - 5 VOLT SUPPLY - PCM
OUTPUT............................15
STANDARD PROCEDURE
STANDARD PROCEDURE - OBTAINING
DIAGNOSTIC TROUBLE CODES..........15
STANDARD PROCEDURE - PINION
FACTOR SETTING.....................15
STANDARD PROCEDURE - QUICK LEARN
PROCEDURE........................15
REMOVAL
REMOVAL - SBEC CONTROLLER.........16
REMOVAL - NGC CONTROLLER..........16
INSTALLATION
INSTALLATION - SBEC CONTROLLER.....17
INSTALLATION.......................17
SLIDING DOOR CONTROL MODULE
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING
SLIDING DOOR CONTROL MODULE......18
REMOVAL.............................18
INSTALLATION.........................19
ELECTRONIC CONTROL
MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING
NOTE: Before replacing the PCM for a failed driver,
control circuit or ground circuit, be sure to checkthe related component/circuit integrity for failures
not detected due to a double fault in the circuit.
Most PCM driver/control circuit failures are caused
by internal component failures (i.e. relay and sole-
noids) and shorted circuits (i.e. pull-ups, drivers
and switched circuits). These failures are difficult to
detect when a double fault has occurred and only
one DTC has set.
RSELECTRONIC CONTROL MODULES8E-1
The BCM utilizes integrated circuitry and informa-
tion carried on the Programmable Communications
Interface (PCI) data bus network along with many
hard wired inputs to monitor many sensor and
switch inputs throughout the vehicle. In response to
those inputs, the internal circuitry and programming
of the BCM allow it to control and integrate many
electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus.
OPERATION
The Body Control Module (BCM) supplies vehicle
occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the BCM is interfaced to the
vehicle's serial bus communications network, referred
to as the Programmable Communications Interface
(PCI) bus.
This network consists of the;
²Powertrain Control Module (PCM)
²Transmission Control Module (TCM)
²Mechanical Instrument Cluster (MIC)
²Occupant Restraint Controller (ORC)
²Compass/Mini-Trip Computer (CMTC)
²Electronic Vehicle Information Center (EVIC)
²Controller Antilock Brake (CAB)
²HVAC Control Module
²Sliding Door Control Modules (driver and pas-
senger side doors)
²Power Liftgate Module (PLG)
²Audio system equipped with RAZ, RBU, RBK,
and RBB radios.
²Sentry Key Remote Entry Module (SKREEM).
²Side Impact Airbag Control Module (SIACM)²Memory Seat Module (MSM)
²Sentry Key Immobilizer Module (SKIM)
The BCM is operational when battery power is
supplied to the module.
The BCM provides the following features:
²Power Door Locks
²Automatic Door Locks
²Battery Protection - The BCM will automatically
turn off all exterior lamps after 3 minutes, and all
interior lamps after 15 minutes after the ignition is
turned off, if they are not turned off by the driver.
²Chime Control
²Compass/Mini-Trip support.
²Interior Lighting (Courtesy/Reading Lamps)
²BCM Diagnostic Reporting
²Electronic Liftgate Release (with Power Door
Locks)
²Exterior Lighting
²Headlamp Time Delay (with/without Automatic
Headlamps)
²Illuminated Entry
²Fade to Off Interior Lamps - This feature dims
the interior lighting (courtesy lamps) gradually if the
BCM does not receive any new inputs that would
cause the interior lamps to remain on.
²Pulse Width Modulated Instrument Panel Dim-
ming
²Door Lock Inhibit - This feature disables the
door lock functions if the key is in the ignition and
either front door is ajar. Pressing the Remote Keyless
Entry (RKE) lock/unlock button under these condi-
tions result in normal lock/unlock activation.
The BCM has the ability to LEARN additional fea-
tures in the vehicle, provided the appropriate switch
input and PCI data bus messages are received. Refer
to the LEARNED FEATURES table.
LEARNED FEATURES
FEATURE LEARNING KEY
REAR WIPER CONTROL ON HVAC CONTROL ON
INSTRUMENT PANELPCI BUS MESSAGE RECEIVED FROM HVAC
CONTROL
AUTOMATIC HEADLAMPS PCI MESSAGE FROM OVERHEAD OR HEADLAMP
SWITCH POSITION (AUTO)
REMOTE KEYLESS ENTRY SKREEM MESSAGE RECEIVED FROM MODULE
FRONT FOG LAMPS HEADLAMP SWITCH POSITION (PARK W/FRONT
FOG LAMPS)
POWER SLIDING DOOR PCI IFR RECEIVED FROM MODULE
THE BCM HAS FOUR SWITCH INPUTS FOR THE POWER SLIDING DOOR FEATURE; LOCATED IN THE
OVERHEAD CONSOLE ARE THE LEFT AND RIGHT SIDE SLIDING DOOR SWITCHES TO ACTIVATE EITHER
OR BOTH SLIDING DOORS UNDER THE PROPER CONDITIONS. ALSO ARE B-PILLAR SWITCHES LOCATED
ON THE LEFT AND RIGHT B-PILLAR POSTS.
POWER LIFTGATE PCI IFR RECEIVED FROM MODULE
RSELECTRONIC CONTROL MODULES8E-3
BODY CONTROL MODULE (Continued)
trical connector on the vehicle wiring harness. The
power source for the CAB is through the ignition
switch in the RUN or ON position. The CAB is on
the PCI bus.
OPERATION
The primary functions of the controller antilock
brake (CAB) are to:
²Monitor the antilock brake system for proper
operation.
²Detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
²Control fluid modulation to the wheel brakes
while the system is in an ABS mode.
²Store diagnostic information.
²Provide communication to the DRBIIItscan tool
while in diagnostic mode.
²Illuminate the amber ABS warning indicator
lamp.
²(With traction control only) Illuminate the TRAC
ON lamp in the message center on the instrument
panel when a traction control event occurs.
²(with traction control only) Illuminate the TRAC
OFF lamp when the amber ABS warning indicator
lamp illuminates.
The CAB constantly monitors the antilock brake
system for proper operation. If the CAB detects a
fault, it will turn on the amber ABS warning indica-
tor lamp and disable the antilock braking system.
The normal base braking system will remain opera-
tional.
NOTE: If the vehicle is equipped with traction con-
trol, the TRAC OFF lamp will illuminate anytime the
amber ABS warning indicator lamp illuminates.The CAB continuously monitors the speed of each
wheel through the signals generated by the wheel
speed sensors to determine if any wheel is beginning
to lock. When a wheel locking tendency is detected,
the CAB commands the CAB command coils to actu-
ate. The coils then open and close the valves in the
HCU that modulate brake fluid pressure in some or
all of the hydraulic circuits. The CAB continues to
control pressure in individual hydraulic circuits until
a locking tendency is no longer present.
The CAB contains a self-diagnostic program that
monitors the antilock brake system for system faults.
When a fault is detected, the amber ABS warning
indicator lamp is turned on and the fault diagnostic
trouble code (DTC) is then stored in a diagnostic pro-
gram memory. A latched fault will disable certain
system functionality for the current ignition cycle. An
unlatched fault will disable certain system function-
ality until the fault condition disappears. These
DTC's will remain in the CAB memory even after the
ignition has been turned off. The DTC's can be read
and cleared from the CAB memory by a technician
using the DRBIIItscan tool. If not cleared with a
DRBIIItscan tool, the fault occurrence and DTC will
be automatically cleared from the CAB memory after
the identical fault has not been seen during the next
3,500 miles. Drive-off may be required for the amber
ABS warning indicator lamp to go out on the next
ignition cycle.
CAB INPUTS
²Wheel speed sensors (four)
²Brake lamp switch
²Ignition switch
²System and pump voltage
²Ground
²Traction control switch (if equipped)
²Diagnostic communication (PCI)
CAB OUTPUTS
²Amber ABS warning indicator lamp actuation
(via BUS)
²Red BRAKE warning indicator lamp actuation
(via BUS)
²Instrument cluster (MIC) communication (PCI)
²Traction control lamps (if equipped)
²Diagnostic communication (PCI, via BUS)
REMOVAL
(1) Disconnect the battery cables.
(2) Remove the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - REMOVAL).
(3) Disconnect the vacuum hose connector at the
tank built into the battery tray.
(4) Remove the screw securing the coolant filler
neck to the battery tray.
Fig. 1 Integrated Control Unit (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
RSELECTRONIC CONTROL MODULES8E-5
CONTROLLER ANTILOCK BRAKE (Continued)
INSTALLATION
(1) Install the Power Liftgate (PLG) control mod-
ule on the D-pillar and install retaining screw.
(2) Connect the wire harness connections to the
PLG control module. Be certain to slide connector
locks to the locked position.
(3) Install the D-pillar trim panel on the vehicle.
(Refer to 23 - BODY/INTERIOR/LEFT D-PILLAR
TRIM PANEL - INSTALLATION)
(4) Connect the battery negative cable.
(5) Using an appropriate scan tool, check and
erase any PLG control module diagnostic trouble
codes.
(6) Verify PLG system operation. Cycle the PLG
through one complete open and close cycle, this will
allow the PLG control module to relearn its cycle
with the new components.
POWERTRAIN CONTROL
MODULE
DESCRIPTION
DESCRIPTION
The Powertrain Control Module (PCM) is a digital
computer containing a microprocessor (Fig. 9). ThePCM receives input signals from various switches
and sensors referred to as Powertrain Control Mod-
ule Inputs. Based on these inputs, the PCM adjusts
various engine and vehicle operations through
devices referred to as Powertrain Control Module
Outputs.
NOTE: PCM Inputs:
²Air Conditioning Pressure Transducer
²Ambient temperature Sensor
²ASD Relay
²Battery Temperature Sensor (NGC)
²Battery Voltage
²Brake Switch
²Camshaft Position Sensor
²Crankshaft Position Sensor
²Distance Sensor (from transmission control mod-
ule)
²EGR Position Feedback
²Engine Coolant Temperature Sensor
²Heated Oxygen Sensors
²Ignition sense
²Intake Air Temperature Sensor
²Knock Sensor
²Leak Detection Pump Feedback
²Manifold Absolute Pressure (MAP) Sensor
²Park/Neutral
²PCI Bus
²Power Steering Pressure Switch
²Proportional Purge Sense
Fig. 8 POWER LIFTGATE CONTROL MODULE
1 - POWER LIFTGATE CONTROL MODULE
2 - RETAINING SCREWS
3 - D-PILLAR
4 - POWER LIFTGATE MOTOR
5 - ELECTRICAL CONNECTORS
Fig. 9 Powertrain Control Module (PCM)
1 - Battery
2 - Power Distribution Center
3 - Powertrain Control Module
RSELECTRONIC CONTROL MODULES8E-11
POWER LIFTGATE CONTROL MODULE (Continued)
²SCI Receive
²Speed Control
²Throttle Position Sensor
²Transmission Control Relay (Switched B+)
²Transmission Pressure Switches
²Transmission Temperature Sensor
²Transmission Input Shaft Speed Sensor
²Transmission Output Shaft Speed Sensor
²Transaxle Gear Engagement
²Vehicle Speed
NOTE: PCM Outputs:
²Air Conditioning Clutch Relay
²Automatic Shut Down (ASD) and Fuel Pump
Relays
²Data Link Connector (PCI and SCI Transmit)
²Double Start Override
²EGR Solenoid
²Fuel Injectors
²Generator Field
²High Speed Fan Relay
²Idle Air Control Motor
²Ignition Coils
²Leak Detection Pump
²Low Speed Fan Relay
²MTV Actuator
²Proportional Purge Solenoid
²SRV Valve
²Speed Control Relay
²Speed Control Vent Relay
²Speed Control Vacuum Relay
²8 Volt Output
²5 Volt Output
²Torque Reduction Request
²Transmission Control Relay
²Transmission Solenoids
²Vehicle Speed
Based on inputs it receives, the powertrain control
module (PCM) adjusts fuel injector pulse width, idle
speed, ignition timing, and canister purge operation.
The PCM regulates the cooling fans, air conditioning
and speed control systems. The PCM changes gener-
ator charge rate by adjusting the generator field.
The PCM adjusts injector pulse width (air-fuel
ratio) based on the following inputs.
²Battery Voltage
²Intake Air Temperature Sensor
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Exhaust Gas Oxygen Content (heated oxygen
sensors)
²Manifold Absolute Pressure
²Throttle Position
The PCM adjusts engine idle speed through the
idle air control motor based on the following inputs.
²Brake Switch²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Park/Neutral
²Transaxle Gear Engagement
²Throttle Position
²Vehicle Speed
The PCM adjusts ignition timing based on the fol-
lowing inputs.
²Intake Air Temperature
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Knock Sensor
²Manifold Absolute Pressure
²Park/Neutral
²Transaxle Gear Engagement
²Throttle Position
The automatic shut down (ASD) and fuel pump
relays are mounted externally, but turned on and off
by the powertrain control module through the same
circuit.
The camshaft and crankshaft signals are sent to
the powertrain control module. If the PCM does not
receive both signals within approximately one second
of engine cranking, it deactivates the ASD and fuel
pump relays. When these relays are deactivated,
power is shut off to the fuel injectors, ignition coils,
fuel pump and the heating element in each oxygen
sensor.
The PCM contains a voltage converter that
changes battery voltage to a regulated 8.0 volts. The
8.0 volts power the camshaft position sensor, crank-
shaft position sensor and vehicle speed sensor. The
PCM also provides a 5.0 volts supply for the engine
coolant temperature sensor, intake air temperature
sensor, manifold absolute pressure sensor and throt-
tle position sensor.
The PCM engine control strategy prevents reduced
idle speeds until after the engine operates for 320 km
(200 miles). If the PCM is replaced after 320 km (200
miles) of usage, update the mileage in new PCM. Use
the DRBIIItscan tool to change the mileage in the
PCM. Refer to the appropriate Powertrain Diagnostic
Manual and the DRBIIItscan tool.
TRANSMISSION CONTROL
CLUTCH VOLUME INDEX (CVI)
An important function of the PCM is to monitor
Clutch Volume Index (CVI). CVIs represent the vol-
ume of fluid needed to compress a clutch pack.
The PCM monitors gear ratio changes by monitor-
ing the Input and Output Speed Sensors. The Input,
or Turbine Speed Sensor sends an electrical signal to
the PCM that represents input shaft rpm. The Out-
put Speed Sensor provides the PCM with output
shaft speed information.
8E - 12 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)