2003 JEEP GRAND CHEROKEE spec

AUDIO
TABLE OF CONTENTS
page page
AUDIO
DESCRIPTION..........................2
OPERATION............................3
DIAGNOSIS AND TESTING - AUDIO..........3
SPECIAL TOOLS
AUDIO SYSTEMS......................6
AMPLIFIER
DESCRIPTION..........................6
OPERATION............................6
DIAGNOSIS AND TESTING - AMPLIFIER......6
REMOVAL.............................6
INSTALLATION..........................6
ANTENNA BODY & CABLE
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING - ANTENNA BODY
AND CABLE..........................7
REMOVAL.............................9
INSTALLATION.........................10
ANTENNA MODULE - EXPORT
DESCRIPTION.........................10
OPERATION...........................11
DIAGNOSIS AND TESTING - ANTENNA
MODULE - EXPORT....................11
REMOVAL.............................12
INSTALLATION.........................12
CD CHANGER
DESCRIPTION.........................12
OPERATION...........................13
DIAGNOSIS AND TESTING - CD CHANGER . . . 13
REMOVAL.............................14
INSTALLATION.........................14
INSTRUMENT PANEL ANTENNA CABLE
REMOVAL.............................15
INSTALLATION.........................15
QUARTER GLASS INTEGRAL ANTENNA -
EXPORT
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - QUARTER
GLASS INTEGRAL ANTENNA - EXPORT....16RADIO
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - RADIO.........16
REMOVAL.............................17
INSTALLATION.........................18
RADIO NOISE SUPPRESSION GROUND STRAP
DESCRIPTION.........................18
REMOVAL
REMOVAL - ENGINE-TO-BODY GROUND
STRAP.............................18
REMOVAL - EXHAUST-TO-BODY GROUND
STRAP.............................19
INSTALLATION
INSTALLATION - ENGINE TO BODY
GROUND STRAP......................19
INSTALLATION - EXHAUST-TO-BODY
GROUND STRAP......................19
REMOTE SWITCHES
DESCRIPTION.........................19
OPERATION...........................20
DIAGNOSIS AND TESTING - REMOTE
SWITCHES..........................20
REMOVAL.............................21
INSTALLATION.........................21
SPEAKER
DESCRIPTION.........................22
OPERATION...........................22
DIAGNOSIS AND TESTING - SPEAKER......23
REMOVAL
REAR DOOR SPEAKER................24
INSTRUMENT PANEL SPEAKER..........24
FRONT DOOR SPEAKER...............24
INSTALLATION
INSTALLATION - REAR DOOR SPEAKER . . . 25
INSTALLATION - INSTRUMENT PANEL
SPEAKER...........................25
INSTALLATION - FRONT DOOR SPEAKER . . 25
WJAUDIO 8A - 1

SPECIAL TOOLS
AUDIO SYSTEMS
AMPLIFIER
DESCRIPTION
Models equipped with the Infinity premium
speaker package have a separate power amplifier
unit. This power amplifier is rated at 180 watts out-
put. The power amplifier unit is mounted to the rear
floor panel under the passenger side rear seat cush-
ion. The power amplifier unit can be accessed for ser-
vice by unlatching and tilting the passenger side rear
seat cushion forward.
The power amplifier unit should be checked if
there is no sound output noted from the speakers.
For diagnosis of the power amplifier, (Refer to 8 -
ELECTRICAL/AUDIO/SPEAKER - DIAGNOSIS
AND TESTING). The power amplifier cannot be
repaired or adjusted and, if faulty or damaged, the
unit must be replaced.
OPERATION
The power amplifier is energized by a fused 12 volt
output from the radio receiver whenever the radio is
turned on. The power amplifier receives the sound
signal inputs for four speaker channels from the
radio receiver, then sends the amplified speaker out-
puts for each of those channels to the six Infinity
speakers. For complete circuit diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
DIAGNOSIS AND TESTING - AMPLIFIER
The power amplifier unit should be checked if
there is no sound output noted from the speakers.
For diagnosis of the power amplifier, (Refer to 8 -
ELECTRICAL/AUDIO/SPEAKER - DIAGNOSIS
AND TESTING). For complete circuit diagrams, refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire har-
ness routing and retention, connector pin-out infor-
mation and location views for the various wire
harness connectors, splices and grounds.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unlatch and lift the right rear seat cushion to
the upright position.
(3) Disconnect the two right body wire harness
connectors from the amplifier (Fig. 1).
(4) Remove the three mounting nuts.
(5) Remove the power amplifier.
INSTALLATION
(1) Position the power amplifier onto the three
floor panel studs.
(2) Install the mounting nuts. Tighten the nuts to
11.8 N´m (105 in. lbs.).
(3) Reconnect the two right body wire harness con-
nectors.
(4) Lower the right rear seat cushion to the floor
panel.
(5) Reconnect the battery negative cable.
Antenna Nut Wrench C-4816
Fig. 1 Power Amplifier Remove/Install
1 - NUT (3)
2 - RIGHT BODY WIRE HARNESS
3 - AMPLIFIER
4 - STUD (3)
5 - RIGHT REAR FLOOR PANEL
8A - 6 AUDIOWJ
AUDIO (Continued)

(2) Touch one ohmmeter test lead to a good clean
ground point on the vehicle fender. Touch the other
test lead to the outer crimp on the antenna coaxial
cable connector under the right end of the instru-
ment panel near the right cowl side inner panel.
Check the ohmmeter reading for continuity.
(3) There should be continuity. The ohmmeter
should register less than one ohm resistance. High or
infinite resistance indicates a loose, corroded, or
damaged connection between the antenna body and
the vehicle body or between the antenna body and
the antenna coaxial cable shield. If not OK, clean the
antenna body to fender mating surfaces and tighten
the antenna cap nut to specifications.
(4) Check the resistance again with an ohmmeter.
If the resistance is still more then one ohm, replace
the faulty antenna body and cable.
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 scuff plate from the right front
door sill. (Refer to 23 - BODY/INTERIOR/DOOR
SILL SCUFF PLATE - REMOVAL) for the proce-
dures.
(3) Remove the trim panel from the right inner
cowl side.(Refer to 23 - BODY/INTERIOR/COWL
TRIM - REMOVAL) for the procedures.
(4) Reach under the passenger side of the instru-
ment panel near the right cowl side inner panel to
disconnect the antenna coaxial cable connector by
pulling it apart while twisting the metal connector
halves (Fig. 4). Do not pull on the cable.
(5) Remove the lower rear half of the inner liner
from the right front fender wheel house. (Refer to 23
- BODY/EXTERIOR/FRONT FENDER - REMOVAL)
for the procedures.
(6) Reach through the rear of the right front
fender wheel house opening to access and unseat the
antenna lead grommet from the hole in the right
cowl side outer panel.(7) Pull the antenna lead coaxial cable and connec-
tor out of the passenger compartment and into the
right front fender wheel house through the hole in
the right cowl side outer panel.
(8) Unscrew the antenna mast from the antenna
base (Fig. 5).
(9) Remove the plastic shroud from the antenna
base cap nut.
(10) Remove the antenna base cap nut using an
antenna nut wrench (Special Tool C-4816) (Fig. 6).
(11) Remove the antenna escutcheon from the
antenna base on the top of the right front fender.
(12) Lower the antenna base from the mounting
hole in the top of the right front fender.
(13) Remove the antenna base and lead from the
rear of the right front fender wheel house opening.
Fig. 4 Antenna Base and Lead Remove/Install
1 - BASE AND LEAD
2 - ESCUTCHEON
3 - MAST
4 - SHROUD
5 - CAP NUT
6 - RIGHT FRONT FENDER
7 - GROMMET
8 - CONNECTOR
WJAUDIO 8A - 9
ANTENNA BODY & CABLE (Continued)

INSTALLATION
(1) Position the antenna base and lead into the
rear of the right front fender wheel house opening.
(2) Insert the antenna base into the mounting hole
in the top of the right front fender.
(3) Install the antenna escutcheon onto the
antenna base on the top of the right front fender.
(4) Install and tighten the antenna base cap nut
using an antenna nut wrench (Special Tool C-4816).
Tighten the cap nut to 6.8 N´m (60 in. lbs.).
(5) Install the plastic shroud onto the antenna
base cap nut.
(6) Install and tighten the antenna mast onto the
antenna base. Tighten the antenna mast to 3.3 N´m
(30 in. lbs.).
(7) Reach through the rear of the right front
fender wheel house opening to access and insert the
antenna lead coaxial cable and connector into the
passenger compartment through the hole in the right
cowl side outer panel.
(8) From the right front fender wheel house, seat
the antenna lead grommet into the hole in the right
cowl side outer panel.
(9) Install the lower rear half of the inner liner
into the right front fender wheel house.
(10) Reach under the passenger side of the instru-
ment panel near the right cowl side inner panel to
reconnect the antenna coaxial cable connector halves.
(11) Install the trim panel onto the right inner
cowl side.
(12) Install the scuff plate onto the right front door
sill.
(13) Reconnect the battery negative cable.
ANTENNA MODULE - EXPORT
DESCRIPTION
The antenna module (Fig. 7) is an electromagnetic
circuit component designed to capture and enhance
RF (Radio Frequency) signals in both the AM and
FM broadcast bands. The antenna module is
mounted to the right rear roof rail under the head-
liner. The modules mounting brackets also double as
the ground circuit. The module has a two wire elec-
trical connector that connects to the electric backlite
integral radio antenna, located on the right rear
quarter glass, a connector for the radio coax cable
and a connector for battery voltage.
Fig. 5 Antenna Mast Remove/Install - Typical
1 - ANTENNA MAST
2 - ADAPTER
3 - CAP NUT
Fig. 6 Antenna Base Cap Nut Remove/Install -
Typical
1 - CAP NUT
2 - ANTENNA ADAPTER
3 - TOOL
8A - 10 AUDIOWJ
ANTENNA BODY & CABLE (Continued)

(5) Connect the two instrument panel wire harness
connectors to the BCM.
(6) Reinstall the instrument panel fuse cover to
the bottom of the BCM and JB unit. (Refer to 8 -
ELECTRICAL/POWER DISTRIBUTION/FUSE
COVER - INSTALLATION).
(7) Connect the battery negative cable.
COMMUNICATION
DESCRIPTION
The Programmable Communication Interface (PCI)
data bus system is a single wire multiplex system
used for vehicle communications. Multiplexing is a
system that enables the transmission of several mes-
sages over a single channel or circuit.
Many of the control modules in a vehicle require
information from the same sensing device. Multiplex-
ing reduces wire harness complexity, sensor current
loads and controller hardware because each sensing
device is connected to only one controller, which
reads and distributes the sensor information to the
other controllers over the data bus. Also, because
each controller on the data bus can access the con-
troller sensor inputs to every other controller on the
data bus, more function and feature capabilities are
possible.
A multiplex system allows the information flowing
between controllers to be monitored using a diagnos-
tic scan tool. This system allows a control module to
broadcast message data out onto the bus where all
other control modules can read the messages that are
being sent. When a module reads a message on the
data bus that it requires, it relays that message to
its microprocessor. Each module ignores the mes-
sages on the data bus that it dosen't recognize.
OPERATION
Data exchange between modules is achieved by
serial transmission of encoded data over a single wire
broadcast network. The PCI data bus messages are
carried over the bus in the form of Variable Pulse
Width Modulated (VPWM) signals. The PCI data bus
speed is an average 10.4 Kilo-bits per second (Kbps).
The voltage network used to transmit messages
requires biasing and termination. Each module on
the PCI data bus system provides its own biasing
and termination. Each module (also referred to as a
node) terminates the bus through a terminating
resistor and a terminating capacitor. The Powertrain
Control Module (PCM) is the only dominant node for
the PCI data bus system.
The PCI bus uses low and high voltage levels to
generate signals. The voltage on the buss varies
between zero and seven and one-half volts. The lowand high voltage levels are generated by means of
variable-pulse width modulation to form signals of
varying length.
When a module is transmitting on the bus, it is
reading the bus at the same time to ensure message
integrity.
Each module is capable of transmitting and receiv-
ing data simultaneously.
The PCI data bus can be monitored using the
DRBIIItscan tool. It is possible for the bus to pass
all DRBIIIttests and still be faulty if the voltage
parameters are all within the specified range and
false messages are being sent.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system (Fig. 4).
OPERATION
The CAB voltage is supplied by the ignition switch
in the RUN position. The CAB contains dual micro-
processors. A logic block in each microprocessor
receives identical sensor signals. These signals are
processed and compared simultaneously. The CAB
contains a self check program that illuminates the
ABS warning light when a system fault is detected.
Faults are stored in a diagnostic program memory
and are accessible with the DRBIIItscan tool. ABS
faults remain in memory until cleared, or until after
the vehicle is started approximately 50 times. Stored
Fig. 4 Controller Antilock Brakes
1 - HCU
2 - MOTOR
3 - CAB
8E - 6 ELECTRONIC CONTROL MODULESWJ
BODY CONTROL 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)

(3) Disconnect the instrument panel wire harness
connector from the SKIM connector.
(4) Remove the screw that secures the SKIM to
the bottom of the steering column housing (Fig. 16).
(5) Disengage the antenna ring of the SKIM from
around the ignition lock cylinder housing.
(6) Remove the SKIM from the steering column.
INSTALLATION
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.
(1) Position the SKIM to the underside of the
steering column (Fig. 16).
(2) Engage the antenna ring of the SKIM around
the ignition lock cylinder housing.
(3) Install and tighten the screw that secures the
SKIM to the bottom of the steering column hous-
ing.Tighten the screw to 3.4 N´m (30 in lbs.).
(4) Reconnect the instrument panel wire harness
connector to the SKIM connector.(5) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(6) Reconnect the battery negative cable.
(7) Perform the SKIS Replacement procedure
using the DRBIIIt.
(8) Perform the SKIS Initialization Procedure
using the DRBIIIt.
TRANSMISSION CONTROL
MODULE
DESCRIPTION
The Transmission Control Module (TCM) is located
in the engine compartment on the right (passenger)
side and is mounted to the inner fender (Fig. 17).
OPERATION
The Transmission Control Module (TCM) controls
all electronic operations of the transmission. The
TCM receives information regarding vehicle opera-
tion from both direct and indirect inputs, and selects
the operational mode of the transmission. Direct
inputs are hardwired to, and used specifically by the
TCM. Indirect inputs originate from other compo-
nents/modules, and are shared with the TCM via the
vehicle communication bus.
Some examples ofdirect inputsto the TCM are:
²Battery (B+) voltage
²Ignition ªONº voltage
²Transmission Control Relay (Switched B+)
²Throttle Position Sensor
²Crankshaft Position Sensor
²Transmission Range Sensor
Fig. 16
Fig. 17 Transmission Control Module Location
1 - TRANSMISSION CONTROL MODULE (TCM)
2 - 60±WAY CONNECTOR
WJELECTRONIC CONTROL MODULES 8E - 19
SENTRY KEY IMMOBILIZER MODULE (Continued)

ENGINE SYSTEMS
TABLE OF CONTENTS
page page
BATTERY SYSTEM......................... 1
CHARGING.............................. 24STARTING............................... 29
BATTERY SYSTEM
TABLE OF CONTENTS
page page
BATTERY SYSTEM
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING - BATTERY
SYSTEM.............................2
CLEANING.............................5
INSPECTION...........................6
SPECIFICATIONS........................6
SPECIAL TOOLS........................7
BATTERY
DESCRIPTION..........................7
OPERATION............................8
DIAGNOSIS AND TESTING - BATTERY.......8
STANDARD PROCEDURE
STANDARD PROCEDURE - BATTERY
CHARGING...........................9
STANDARD PROCEDURE - USING MICRO
420 ELECTRICAL TESTER..............10
STANDARD PROCEDURE - BUILT-IN
INDICATOR TEST.....................11
STANDARD PROCEDURE - OPEN-CIRCUIT
VOLTAGE TEST.......................12
STANDARD PROCEDURE - IGNITION-OFF
DRAW TEST.........................13STANDARD PROCEDURE - CHECKING
BATTERY ELECTROLYTE LEVEL.........14
REMOVAL.............................15
INSTALLATION.........................15
BATTERY HOLDDOWN
DESCRIPTION.........................16
OPERATION...........................16
REMOVAL.............................16
INSTALLATION.........................16
BATTERY CABLE
DESCRIPTION.........................17
OPERATION...........................18
DIAGNOSIS AND TESTING - BATTERY
CABLES............................18
REMOVAL.............................19
INSTALLATION.........................20
BATTERY TRAY
DESCRIPTION.........................21
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................23
WJENGINE SYSTEMS 8F - 1