seat memory JEEP GRAND CHEROKEE 2003 WJ / 2.G Workshop Manual

tions also allows the driver to set steering wheel tilt
and seat position to the most comfortable position.
The position of the brake and accelerator pedals can
be adjusted without compromising safety or comfort
in actuating the pedals. Repositioning the pedals
does not change the effort required for actuation.
Change of pedal position is accomplished by means
of a motor driven screw. Operating the adjustable
pedal switch activates the pedal drive motor. The
pedal drive motor turns a screw that changes the
position of the brake and accelerator pedals. The
pedal can be moved rearward (closer to the driver) or
forward (away from driver). The brake pedal is
moved on its drive screw to a position where the
driver feels most comfortable (Fig. 52).
The accelerator pedal is moved at the same time
and the same distance as the brake pedal. The accel-
erator pedal adjustment screw is turned by a flexible
shaft slaved off the brake adjustment screw.
Neither the pedal drive motor nor drive mecha-
nism are subject to the mechanical stress of brake or
accelerator application.
²SYSTEM FEATURES:
²Range of Adjustment: The pedals may be
adjusted up to 3 in. (75 mm)
²Pedal Adjustment Speed: 0.5 in./sec (12.5
mm/sec)
²Pedal Adjustment Inhibitors: Pedal adjust-
ment is inhibited when the vehicle is in reverse or
when cruise control is activated.
²Memory: An optional memory feature is avail-
able. This allows storing of one or two preferred
pedal positions in the Adjustable Pedal Module
(APM). A preferred position can be stored and
recalled using the door-mounted switches. A stored
pedal position can be recalled (but not stored)
using the Remote Keyless Entry (RKE).
²
Adjustable Pedal Feedback Message: The Elec-
tronic Vehicle Information Center (EVIC) will display
a message when the APS is disabled. ie:9Adjustable
Pedal Disabled - Cruise Control Engaged9or9Adjust-
able Pedal Disabled - Vehicle in Reverse9.
²Damage Prevention: Foot pressure or debris
can stall pedal adjustment. In order to avoid dam-
age to system components during pedal adjust-
ment, the APM will monitor pedal position sensor
voltage. If the APM does not detect expected volt-
age change within 1.5 seconds, it will cut power to
the adjustable pedal motor.
OPERATION
The brake pedal is attached to the booster push
rod. When the pedal is depressed, the primary
booster push rod is depressed which moves the
booster secondary rod. The booster secondary rod
depresses the master cylinder piston.
REMOVAL
REMOVAL - NON-ADJUSTABLE PEDAL
(1) Remove retainer clip that holds booster to
pedal pin (Fig. 53).
Fig. 52 ADJUSTABLE PEDALS ASSEMBLY
1 - HARNESS
2 - ADJUSTABLE PEDAL BRACKET
3 - CABLE
4 - ACCELERATOR PEDAL
5 - BRAKE PEDAL
6 - ADJUSTABLE PEDAL MOTOR
7 - BRAKE LIGHT SWITCH
8 - ADJUSTABLE PEDALS MODULE
Fig. 53 Push Rod Retainer Clip
1 - RETAINER CLIP
2 - PUSH ROD
3 - PEDAL PIN
5 - 26 BRAKES - BASEWJ
PEDAL (Continued)

AUDIO
DESCRIPTION
An audio system is standard factory-installed
equipment on this model. The standard equipment
audio system includes an AM/FM/cassette (RBB sales
code) radio receiver, and speakers in six locations.
Several combinations of radio receivers and speaker
systems are offered as optional equipment on this
model. The audio system uses an ignition switched
control of battery current so that the system will only
operate when the ignition switch is in the On or
Accessory positions.
A Compact Disc (CD) changer with a ten disc mag-
azine, remote radio switches with six functions
mounted to the backs of the steering wheel spokes,
and a memory system that automatically stores and
recalls up to twenty radio station presets (ten AM
and ten FM) and the last station listened to for two
drivers are optional factory-installed equipment on
this model. Refer to Electrical, Power Seats for more
information on the memory system.
The audio system includes the following compo-
nents:
²Antenna
²Compact disc changer (available with RBP sales
code radio receivers only)
²Power amplifier (with premium speaker system
only)
²Radio noise suppression components
²Radio receiver
²Remote radio switches
²Speakers
Certain functions and features of the audio system
rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. The
PCI data bus network allows the sharing of sensor
information. This helps to reduce wire harness com-
plexity, internal controller hardware, and component
sensor current loads. At the same time, this system
provides increased reliability, enhanced diagnostics,
and allows the addition of many new feature capabil-
ities. For diagnosis of these electronic modules or of
the PCI data bus network, the use of a DRB scan
tool and the proper Diagnostic Procedures manual
are recommended.
The other electronic modules that may affect audio
system operation are as follows:
²Body Control Module (BCM)- (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/BODY CONTROL/CENTRAL TIMER MODUL
- DESCRIPTION) for more information.
²Driver Door Module (DDM)(Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-ULES/DRIVER DOOR MODULE - DESCRIPTION)
for more information.
²Passenger Door Module (PDM)(Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/DRIVER DOOR MODULE - DESCRIPTION)
for more information.
The audio system includes the following major
components, which are described in further detail
elsewhere in this service information:
²Amplifier- On models equipped with the
optional premium speaker system, an audio power
amplifier is located on the rear floor panel under-
neath the right end of the rear seat cushion in the
passenger compartment.
²Antenna Body and Cable- The most visible
component of the antenna body and cable are the
antenna adapter and the antenna cap nut, which are
located on the top of the right front fender panel of
the vehicle, near the right end of the cowl plenum.
²Antenna Mast- The antenna mast is a metal
rod that extends upward from the antenna body and
cable on the top of the right front fender panel of the
vehicle, near the right end of the cowl plenum.
²Radio- The radio for this model is located in
the instrument panel center stack area, inboard of
the instrument cluster and above the heater and air
conditioner controls.
²Radio Noise Suppression Ground Strap-A
radio noise suppression ground strap is installed
between the rear of the engine cylinder head(s) and
the dash panel sheet metal in the engine compart-
ment.
²Speaker- The standard speaker system
includes six speakers in six locations, while the pre-
mium speaker system includes an amplifier for the
six speakers in six locations.
Hard wired circuitry connects the audio system
components to each other through the electrical sys-
tem of the vehicle. These hard wired circuits are
integral to several wire harnesses, which are routed
throughout the vehicle and retained by many differ-
ent methods. These circuits may be connected to each
other, to the vehicle electrical system and to the
audio system components through the use of a com-
bination of soldered splices, splice block connectors
and many different types of wire harness terminal
connectors and insulators. Refer to the appropriate
wiring information in this service manual for com-
plete standard and premium audio system circuit
diagrams. The wiring information includes 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 har-
ness connectors, splices, and grounds.
8A - 2 AUDIOWJ

OPERATION
The audio system components are designed to pro-
vide audio entertainment and information through
the reception, tuning and amplification of locally
broadcast radio signals in both the Amplitude Modu-
lating (AM) and Frequency Modulating (FM) com-
mercial frequency ranges. Electromagnetic radio
signals that are broadcast from a radio station
induce electrical modulations into the audio system
antenna mast. The antenna body and cable conduct
these weak signals from the antenna mast to the
radio. The radio then tunes and amplifies these weak
radio frequency signals into stronger electrical audio
signals that are required in order to operate the
audio system speakers. The speakers convert these
electrical signals into air movement, which repro-
duces the sounds being broadcast by the radio sta-
tion.
Some audio systems also offer the user the option
of selecting from and listening to prerecorded audio
cassette tapes, audio compact discs, or both. Regard-
less of the media type, the audio system components
provide the user with the ability to electronically
amplify and adjust the audio signals being repro-
duced by the speakers within the vehicle to suit the
preferences of the vehicle occupants.
The audio system components operate on battery
current received through a fuse in the Junction Block
(JB) on a fused ignition switch output (run-acc) cir-
cuit so that the system will only operate when the
ignition switch is in the On or Accessory positions.
On vehicles that are equipped with the optional
remote radio switches, the BCM receives hard wired
resistor multiplexed inputs from the remote radio
switches. The programming in the BCM allows it to
process those inputs and send the proper messages to
the radio receiver over the PCI data bus to control
the radio volume up or down, station seek up or
down, preset station advance, and mode advance
functions.On vehicles equipped with the optional memory
system, when the DDM receives a Driver 1 or Driver
2 memory recall input from the memory switch on
the driver side front door trim panel or a memory
recall message from the Remote Keyless Entry (RKE)
receiver in the PDM, the DDM sends a memory
recall message back to the radio receiver over the
PCI data bus to recall the radio station presets and
last station listened to information.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of each of the available audio systems.
DIAGNOSIS AND TESTING - AUDIO
Any diagnosis of the Audio system should
begin with the use of the DRB IIItdiagnostic
tool. For information on the use of the DRB
IIIt, refer to the appropriate Diagnostic Service
Manual.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
WJAUDIO 8A - 3
AUDIO (Continued)

problem being diagnosed is related to one of the
symptoms listed below, be certain to check the
remote radio switches and circuits. (Refer to 8 -
ELECTRICAL/AUDIO/REMOTE SWITCHES -
OPERATION).
²Stations changing with no remote radio switch
input
²Radio memory presets not working properly
²Volume changes with no remote radio switch
input
²Remote radio switch buttons taking on other
functions
²CD player skipping tracks
²Mode (AM, FM, CD, CD changer) changes with
no remote radio switch input
²Remote radio switch inoperative.
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
CAUTION: The speaker output of the radio receiver
is a ªfloating groundº system. Do not allow any
speaker lead to short to ground, as damage to the
radio receiver may result.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the junction block. If OK, go to Step 3. If not OK,
repair the open fused B(+) circuit to the Power Dis-
tribution Center (PDC) fuse as required.
(3) Check the fused ignition switch output (acc/
run) fuse in the junction block. If OK, go to Step 4. If
not OK, repair the shorted circuit or component as
required and replace the faulty fuse(s).(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (acc/run) fuse in the junction block. If OK, go
to Step 5. If not OK, repair the open fused ignition
switch output (acc/run) circuit to the ignition switch
as required.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the radio receiver from the instrument
panel, but do not disconnect the wire harness connec-
tors. Check for continuity between the radio receiver
chassis and a good ground. There should be continu-
ity. If OK, go to Step 6. If not OK, repair the open
ground circuit to ground as required.
(6) Test the radio receiver antenna. (Refer to 8 -
ELECTRICAL/AUDIO/ANTENNA BODY & CABLE -
DIAGNOSIS AND TESTING). If OK, go to Step 7. If
not OK, replace the faulty antenna or coaxial cable
as required.
(7) Connect the battery negative cable. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (acc/run)
circuit cavity of the 22 pin radio wire harness connec-
tor. If OK, go to Step 8. If not OK, repair the open
fused ignition switch output (acc/run) circuit to the
junction block fuse as required.
(8) Turn the ignition switch to the Off position.
Check for battery voltage at the fused B(+) circuit
cavity of the 22 pin radio wire harness connector. If
OK, replace the faulty radio receiver. If not OK,
repair the open fused B(+) circuit to the junction
block fuse as required.
REMOVAL
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center upper bezel from the instru-
ment panel.(Refer to 23 - BODY/INSTRUMENT
PANEL - REMOVAL).
(3) Remove the four screws that secure the radio
receiver to the instrument panel (Fig. 12).
WJAUDIO 8A - 17
RADIO (Continued)

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
ELECTRONIC CONTROL MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING.......................1
ADJUSTABLE PEDALS MODULE
REMOVAL.............................2
INSTALLATION..........................3
BODY CONTROL MODULE
DESCRIPTION..........................3
OPERATION............................3
DIAGNOSIS AND TESTING - BODY CONTROL
MODULE.............................4
REMOVAL.............................5
INSTALLATION..........................5
COMMUNICATION
DESCRIPTION..........................6
OPERATION............................6
CONTROLLER ANTILOCK BRAKE
DESCRIPTION..........................6
OPERATION............................6
REMOVAL.............................7
INSTALLATION..........................7
DATA LINK CONNECTOR
DESCRIPTION - DATA LINK CONNECTOR.....7
OPERATION - DATA LINK CONNECTOR......7
DOOR MODULE
DESCRIPTION..........................7
OPERATION............................9
DIAGNOSIS AND TESTING - DOOR MODULE . 10
REMOVAL.............................10
INSTALLATION.........................10
MEMORY HEATED SEAT/MIRROR MODULE
DESCRIPTION.........................10OPERATION...........................11
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE............................11
REMOVAL.............................11
INSTALLATION.........................12
POWERTRAIN CONTROL MODULE
DESCRIPTION
DESCRIPTION - PCM..................12
MODES OF OPERATION................12
DESCRIPTION - 5 VOLT SUPPLIES.......14
DESCRIPTION - IGNITION CIRCUIT SENSE . 14
DESCRIPTION - POWER GROUNDS......15
DESCRIPTION - SENSOR RETURN.......15
OPERATION
OPERATION - PCM....................15
OPERATION - 5 VOLT SUPPLIES.........16
OPERATION - IGNITION CIRCUIT SENSE . . . 16
REMOVAL.............................16
INSTALLATION.........................17
SENTRY KEY IMMOBILIZER MODULE
DESCRIPTION.........................17
OPERATION...........................17
REMOVAL.............................18
INSTALLATION.........................19
TRANSMISSION CONTROL MODULE
DESCRIPTION.........................19
OPERATION...........................19
STANDARD PROCEDURE
STANDARD PROCEDURE - TCM QUICK
LEARN..............................22
ELECTRONIC CONTROL
MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING
NOTE: Before replacing the PCM, be sure to check
the related component/circuit integrity for failures
not detected due to a double fault in the circuit.
Most PCM failures are caused by internal compo-
nent failures (i.e. relays and solenoids) and shorted
circuits (i.e. pull-ups, drivers, and switched cir-
cuits). These failures are difficult to detect when a
double fault has occurred and only one DTC has
been set.When a PCM (JTEC) and the SKIM are replaced
at the same time, perform the following steps in
order:
(1) Program the new PCM (JTEC).
(2) Program the new SKIM.
(3) Replace all ignition keys and program them to
the new SKIM.
PROGRAMMING THE PCM (JTEC)
The SKIS Secret Key is an ID code that is unique
to each SKIM. This code is programmed and stored
in the SKIM, the PCM, and the ignition key tran-
sponder chip(s). When replacing the PCM, it is nec-
essary to program the secret key into the new PCM
using the DRBIIItscan tool. Perform the following
steps to program the secret key into the PCM.
WJELECTRONIC CONTROL MODULES 8E - 1

BCM programming then performs those tasks and
provides features through both PCI data bus commu-
nication with other electronic modules and hard
wired outputs to a number of relays. These relays
provide the BCM with the ability to control numer-
ous high current accessory systems in the vehicle.
The BCM circuitry operates on battery current
received through fuses in the Junction Block (JB) on a
non-switched fused B(+) circuit, a fused ignition switch
output (start-run) circuit, and a fused ignition switch
output (run-accessory) circuit. This arrangement allows
the BCM to provide some features regardless of the
ignition switch position. The BCM circuitry is grounded
through the chassis beneath the center console.
The BCM monitors its own internal circuitry as
well as many of its input and output circuits, and
will store a Diagnostic Trouble Code (DTC) in elec-
tronic memory for any failure it detects. These DTCs
can be retrieved and diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
HARD WIRED INPUTS
The hard wired inputs to the BCM include the fol-
lowing:
²A/C switch signal
²Ambient temperature sensor signal
²Body control module flash enable
²Coolant level switch sense
²Door ajar switch sense (two circuits - one left
rear, and one right rear)
²Driver seat heater switch mux
²Fog lamp switch sense
²Fused B(+)
²Fused ignition switch output (run-acc)
²Fused ignition switch output (st-run)
²Ground (five circuits - two Z1, and three Z2)
²Hazard switch sense
²Headlamp switch mux
²High beam switch sense
²Hood ajar switch sense (export)
²Key-in ignition switch sense
²Liftgate ajar switch sense
²Liftgate courtesy disable
²Liftgate flip-up ajar switch sense
²Panel lamps dimmer signal
²Park lamp relay output
²Passenger seat heater switch mux
²PCI bus
²Radio control mux
²Rear window defogger switch sense
²Seat belt switch sense
²Ultralight sensor signal
²Washer fluid switch sense
²Washer pump switch sense
²Windshield wiper switch mux
²Wiper park switch sense
MESSAGING
The BCM uses the following messages received
from other electronic modules over the PCI data bus:
²Accessory Delay Control (DDM/PDM)
²Battery Temperature (PCM)
²Chime Request (EMIC, EVIC, SKIM)
²Cylinder Lock Switch Status (DDM)
²Door Ajar Status/Front Doors (DDM/PDM)
²Door Lock Status (DDM/PDM)
²Engine Model (PCM)
²Engine RPM (PCM)
²Engine Temperature (PCM)
²English/Metric Default (EMIC)
²Fuel Tank Level (PCM)
²Fuel Used/Injector Pulses (PCM)
²Panic Control (PDM)
²Programmable Features Preferences/Audible &
Optical Chirps/Headlamp Delay (EVIC)
²RKE Status (PDM)
²Vehicle Identification Number (PCM)
²Vehicle Speed (PCM)
The BCM provides the following messages to other
electronic modules over the PCI data bus:
²A/C Switch Status (PCM)
²Ambient Temperature Data (AZC/EVIC/PCM)
²Average/Instantaneous Fuel Economy (EVIC)
²Country Code (EMIC)
²Courtesy Lamp Status (DDM/PDM)
²Distance To Empty (EVIC)
²Elapsed Ignition On Timer (EVIC)
²English/Metric Status (EMIC)
²Front & Rear Door Ajar Status (EVIC)
²Front & Rear Fog Lamp Status (EMIC)
²Heated Seat Switch Status (HSM/MHSM)
²High Beam Status (EMIC)
²Ignition Off Timer (EVIC)
²Ignition Switch Position (DDM/PDM)
²Key-In Ignition Status (DDM/PDM)
²Low Beam Status (EMIC)
²Panel Lamp Status (AZC/EMIC/Radio)
²Rear Window Defogger Relay Status (DDM/
PDM)
²Remote Radio Switch Status (Radio)
²Seatbelt Status (EMIC/MHSM/MSM)
DIAGNOSIS AND TESTING - BODY CONTROL
MODULE
The hard wired inputs to and outputs from the
Body Control Module (BCM) may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. Refer to the appropriate wiring information.
Conventional diagnostic methods may not prove
conclusive in the diagnosis of the BCM. In order to
obtain conclusive testing of the BCM, the Program-
mable Communications Interface (PCI) data bus net-
work and all of the electronic modules that provide
8E - 4 ELECTRONIC CONTROL MODULESWJ
BODY CONTROL MODULE (Continued)

lamp flash features), Unlock with the optional RKE
unlock, and Panic Mode functions. The optional RKE
features are programmable.
²Switch Illumination- Each door module pro-
vides control of the power window and power lock
switch illumination for the front and rear doors on
the same side of the vehicle. The DDM provides con-
trol of the power mirror switch illumination.
²Window Lockout- The DDM monitors and
transmits the status of its integral window lockout
switch to provide the power window lockout feature
and coordinate power window switch knob illumina-
tion.
The door modules are serviced only as complete
units. Many of the features in the vehicle controlled
or supported by the door modules are programmable
using either the Electronic Vehicle Information Cen-
ter (EVIC) user interface, or the DRBIIItscan tool. If
a door module is damaged or faulty, the entire door
module unit must be replaced.
OPERATION
The microprocessor-based DDM and PDM hard-
ware and software monitors integral and hard wired
external switch inputs as well as those resources it
shares with other electronic modules in the vehicle
through its communication over the PCI data bus
network. The internal programming and all of these
inputs allow the DDM or PDM microprocessor to
determine the tasks it needs to perform and their
priorities, as well as both the standard and optional
features that it should provide.
The DDM and PDM are powered by a fused bat-
tery circuit so that they can operate regardless of the
ignition switch position. The DDM and PDM cir-
cuitry is grounded to the chassis beneath the front
seat.
The DDM and PDM can be diagnosed using a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
HARD WIRED INPUTS
The hard wired inputs to the door modules include
the following:
²Door ajar switch sense
²Driver door key cylinder switch sense (DDM)
²Fused B(+)
²Ground
²Memory switch mux (DDM)
²Mirror horizontal position signal
²Mirror vertical position signal
²PCI bus
HARD WIRED OUTPUTS
The hard wired outputs of the door modules
include the following:
²Courtesy lamp driver
²Courtesy lamp ground
²Diagnostic out (DDM)
²Door/liftgate lock driver
²Door/liftgate unlock driver
²Door switch illumination (rear power window)
²Front window driver (down)
²Front window driver (up)
²Memory set indicator driver (DDM)
²Memory switch return (DDM)
²Mirror common driver
²Mirror heater ground
²Mirror heater 12V supply
²Rear window driver (down)
²Rear window driver (up)
²Mirror horizontal driver
²Mirror sensor ground
²Mirror vertical driver
²PCI bus
²Switch illumination driver (memory - DDM)
MESSAGING
The door modules use the following messages
received from other electronic modules over the PCI
data bus:
²Accessory Delay Control (PDM)
²Courtesy Lamp Status (BCM)
²Door Ajar Status/Rear Doors (BCM)
²Door Lock Status (DDM/PDM)
²Ignition Switch Position (BCM)
²Key-In Ignition Status (BCM)
²Programmable Features Preferences/Auto Lock/
Auto Unlock/RKE Unlock Sequence/RKE Link to
Memory (EVIC)
²Memory Recall (DDM)
²Rear Window Defogger Relay Status (BCM)
²Vehicle Speed (PCM)
The door modules provide the following messages
to other electronic modules over the PCI data bus:
²Cylinder Lock Switch Status (BCM)
²Door Ajar Status/Front Doors (BCM/DDM/PDM)
²Door Lock Status (DDM/PDM)
²Memory Recall (PDM/MHSM/MSM/Radio)
²Memory Set Switch Status (PDM/MHSM/MSM/
Radio)
²Panic Control (BCM)
²Power Window Switch Status (PDM)
²RKE Status (BCM/DDM)
²Window Lockout Switch Status (PDM)
WJELECTRONIC CONTROL MODULES 8E - 9
DOOR MODULE (Continued)

DIAGNOSIS AND TESTING - DOOR MODULE
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
The hard wired inputs to and outputs from the
Driver Door Module (DDM) or the Passenger Door
Module (PDM) may be diagnosed and tested using
conventional diagnostic tools and procedures. It is
suggested that the proper operation of the inopera-
tive power window motor, power door lock motor,
power liftgate lock motor, power mirror motors, or
heated mirror grid be confirmed using jumper wires
to bypass the door module. If the inoperative compo-
nent operates when the door module is bypassed,
check the circuits between the component and the
door module, as well as the fused B(+) and ground
circuits of the door module for shorts or opens.
These conventional diagnostic methods may not
prove conclusive in the diagnosis of the DDM or the
PDM. In order to obtain conclusive testing of these
modules, the Programmable Communications Inter-
face (PCI) data bus network and all of the modules
that provide inputs to or receive outputs from the
door modules must also be checked. The most reli-
able, efficient, and accurate means to diagnose the
DDM, the PDM, the PCI data bus network, and the
modules that provide inputs to or receive outputs
from the door modules requires the use of a DRBIIIt
scan tool and the appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the front door.
(Refer to 23 - BODY/DOOR - FRONT/TRIM PANEL -
REMOVAL).
(3) Remove the door module from the back of the
front door trim panel (Fig. 8).
(4) Remove the door module from the front door
trim panel.
INSTALLATION
(1) Position the door module onto the front door
trim panel.
(2) Install the door module to the back of the front
door trim panel (Fig. 8). Tighten the screws to 2.2
N´m (20 in. lbs.).
(3) Reinstall the trim panel onto the front door.
(Refer to 23 - BODY/DOOR - FRONT/TRIM PANEL -
INSTALLATION).
(4) Reconnect the battery negative cable.
MEMORY HEATED SEAT/
MIRROR MODULE
DESCRIPTION
There are two different modules that can be used
in the optional heated seat system. The Heated Seat
Module (HSM) is used on vehicles that are not
equipped with the optional Memory System. The
Memory Heated Seat Module (MHSM) is used on
vehicles that are equipped with the optional Memory
System and the optional heated seat system.Refer to
Memory Systemin Power Seat Systems for more
information on the memory system option.
The module is mounted on a bracket that is located
between the power seat track and the seat cushion
frame (Fig. 9). The HSM or MHSM is used to control
the heated seat system functions for both front seats.
The HSM or MHSM contains a central processing
unit that communicates with other modules on the
Fig. 8 Door Module Remove/Install
1 - FRONT DOOR TRIM PANEL
2 - SCREW (5)
3 - DOOR MODULE
8E - 10 ELECTRONIC CONTROL MODULESWJ
DOOR MODULE (Continued)

Programmable Communications Interface (PCI) data
bus network.
For diagnosis of the HSM, MHSM or the PCI data
bus, a DRBIIItscan tool and the proper Diagnostic
Procedures manual are recommended. The HSM or
MHSM cannot be repaired and, if faulty or damaged,
it must be replaced.
OPERATION
The MSM receives hard wired inputs from the
power seat switch and the potentiometers on each of
the driver side power seat motors. The MSM receives
messages over the PCI data bus from the Driver
Door Module (DDM) (memory switch status), the
Powertrain Control Module (PCM) (vehicle speed sta-
tus), and the Body Control Module (seat belt switch
status).The MSM will prevent the seat memory recall
function from being initiated if the driver side seat
belt is buckled, if the transmission gear selector lever
is not in the Park or Neutral positions, or if the vehi-
cle is moving.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE
Visually inspect the related wiring harness connec-
tors. Look for broken, bent, pushed out, or corroded
terminals. If any of the above conditions are present,
repair as necessary. If not, use a DRBIIItscan tool
and the proper Diagnostic Procedures Manual to test
the HSM or MHSM. For complete circuit diagrams,
refer toPower Seat Premium I/IIIin Wiring Dia-
grams.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the driver side front bucket seat from
the power seat track unit. Refer toBucket Seat
Track Adjusterin Body for the procedure.
(3) Lift the heated seat module off of the power
seat track and disconnect the power seat wire har-
ness connectors (Fig. 10).
(4) Remove the module from the bracket.
Fig. 9 Heated Seat Module Remove/Install
1 - NUT (4)
2 - SEAT CUSHION FRAME
3 - POWER SEAT TRACK
4 - STUD (4)
5 - MODULE
6 - BRACKET
Fig. 10 Heated Seat Module Remove/Install
1 - NUT (4)
2 - SEAT CUSHION FRAME
3 - POWER SEAT TRACK
4 - STUD (4)
5 - MODULE
6 - BRACKET
WJELECTRONIC CONTROL MODULES 8E - 11
MEMORY HEATED SEAT/MIRROR MODULE (Continued)

INSTALLATION
(1) Install the MHSM,HSM into the bracket.
(2) Position the heated seat module and mounting
bracket onto the power seat track.
(3) Reconnect the power seat wiring harness con-
nectors to the heated seat module.
(4) Install the driver side front bucket seat onto
the power seat track unit (Refer to 23 - BODY/
SEATS/SEAT TRACK ADJUSTER - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
NOTE: If the vehicle is equipped with the optional
Memory System, following installation, it will be
necessary to initialize the Memory Heated Seat
Module (MHSM). In order to function properly, the
MHSM must ªlearnº the sensor values of each of
the power seat motor position transducers in each
of the adjuster hard stop positions. This is done by
performing the ªReset Guard Bandº procedure
using a DRBIIITscan tool and the proper Diagnostic
Procedures manual.
WARNING: THE ªRESET GUARD BANDº PROCE-
DURE WILL CAUSE THE DRIVER SIDE FRONT
SEAT TO AUTOMATICALLY ADJUST TO EACH OF
ITS TRAVEL LIMITS. BE CERTAIN THAT NO ONE IS
SEATED IN THE VEHICLE AND THAT THERE IS
NOTHING IN THE VEHICLE THAT WILL OBSTRUCT
SEAT MOVEMENT. FAILURE TO OBSERVE THIS
WARNING COULD RESULT IN PERSONAL INJURIES
AND/OR VEHICLE DAMAGE.
POWERTRAIN CONTROL
MODULE
DESCRIPTION
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located
in the engine compartment (Fig. 11). The PCM is
referred to as JTEC.
MODES OF OPERATION
As input signals to the Powertrain Control Module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
During Open Loop modes, the PCM receives input
signals and responds only according to preset PCMprogramming. Input from the oxygen (O2S) sensors
is not monitored during Open Loop modes.
During Closed Loop modes, the PCM will monitor
the oxygen (O2S) sensors input. This input indicates
to the PCM whether or not the calculated injector
pulse width results in the ideal air-fuel ratio. This
ratio is 14.7 parts air-to-1 part fuel. By monitoring
the exhaust oxygen content through the O2S sensor,
the PCM can fine tune the injector pulse width. This
is done to achieve optimum fuel economy combined
with low emission engine performance.
The fuel injection system has the following modes
of operation:
²Ignition switch ON
²Engine start-up (crank)
²Engine warm-up
²Idle
²Cruise
²Acceleration
²Deceleration
²Wide open throttle (WOT)
²Ignition switch OFF
The ignition switch On, engine start-up (crank),
engine warm-up, acceleration, deceleration and wide
open throttle modes are Open Loop modes. The idle
and cruise modes, (with the engine at operating tem-
perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system
is activated by the ignition switch, the following
actions occur:
Fig. 11 PCM Location
1 - PCM
2 - COOLANT TANK
8E - 12 ELECTRONIC CONTROL MODULESWJ
MEMORY HEATED SEAT/MIRROR MODULE (Continued)