2003 JEEP GRAND CHEROKEE Audio

GROUP TAB LOCATOR
Introduction
0Lubrication & Maintenance
2Suspension
3Driveline
5Brakes
7Cooling
8AAudio
8BChime/Buzzer
8EElectronic Control Modules
8FEngine Systems
8GHeated Systems
8HHorn
8IIgnition Control
8JInstrument Cluster
8LLamps
8MMessage Systems
8NPower Systems
8ORestraints
8PSpeed Control
8QVehicle Theft Security
8RWipers/Washers
8WWiring
9Engine
11Exhaust System
13Frame & Bumpers
14Fuel System
19Steering
21Transaxle
22Tires/Wheels
23Body
24Heating & Air Conditioning
25Emissions Control
Service Manual Comment Forms (Rear of Manual)

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

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)

AUDIO SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO AUDIO 1. Fuse faulty. 1. Check radio fuse in Junction Block (JB) and
Ignition-Off Draw (IOD) fuse in Power Distribution
Center (PDC). Replace fuses, if required.
2. Radio connector faulty. 2. Check for loose or corroded radio connector.
Repair, if required.
3. Wiring faulty. 3. Check for battery voltage at radio connector.
Repair wiring, if required.
4. Radio ground faulty. 4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Radio faulty. 5. (Refer to 8 - ELECTRICAL/AUDIO/RADIO -
DIAGNOSIS AND TESTING).
6. Speakers faulty. 6. (Refer to 8 - ELECTRICAL/AUDIO/SPEAKER -
DIAGNOSIS AND TESTING).
7. Amplifier faulty (if
equipped).7. (Refer to 8 - ELECTRICAL/AUDIO/AMPLIFIER
- DIAGNOSIS AND TESTING).
NO RADIO DISPLAY 1. Fuse faulty. 1. Check radio fuse in Junction Block (JB) and
Ignition-Off Draw (IOD) fuse in Power Distribution
Center (PDC). Replace fuses, if required.
2. Radio connector faulty. 2. Check for loose or corroded radio connector.
Repair, if required.
3. Wiring faulty. 3. Check for battery voltage at radio connector.
Repair wiring, if required.
4. Radio ground faulty. 4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Radio faulty. 5. (Refer to 8 - ELECTRICAL/AUDIO/RADIO -
DIAGNOSIS AND TESTING).
CLOCK WILL NOT KEEP
SET TIME1. Fuse faulty. 1. Check Ignition-Off Draw (IOD) fuse in the
Power Distribution Center (PDC). Replace fuse, if
required.
2. Radio connector faulty. 2. Check for loose or corroded radio connector.
Repair, if required.
3. Wiring faulty. 3. Check for battery voltage at radio connector.
Repair wiring, if required.
4. Radio ground faulty. 4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Radio faulty. 5. (Refer to 8 - ELECTRICAL/AUDIO/RADIO -
DIAGNOSIS AND TESTING).
8A - 4 AUDIOWJ
AUDIO (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
POOR RADIO RECEPTION 1. Antenna faulty. 1. (Refer to 8 - ELECTRICAL/AUDIO/ANTENNA
BODY & CABLE - DIAGNOSIS AND TESTING).
2. Radio ground faulty. 2. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
3. Radio noise suppression
faulty.3. (Refer to 8 - ELECTRICAL/AUDIO/RADIO
NOISE SUPPRESSION - DIAGNOSIS AND
TESTING).
4. Radio faulty. 4. (Refer to 8 - ELECTRICAL/AUDIO/RADIO -
DIAGNOSIS AND TESTING).
NO/POOR TAPE
OPERATION1. Faulty tape. 1. Insert known good tape and test operation.
2. Foreign objects behind
tape door.2. Remove foreign objects and test operation.
3. Dirty cassette tape head. 3. Clean head with Mopar Cassette Head
Cleaner.
4. Faulty tape deck. 4. Exchange or replace radio, if required.
NO COMPACT DISC
OPERATION, OR CD
SKIPPING SOUND1. Faulty CD. 1. Insert known good CD and test operation.
2. Foreign material on CD. 2. Clean CD and test operation.
3. Condensation on CD or
optics.3. Allow temperature of vehicle interior to stabilize
and test operation.
4. Faulty CD player. 4. Exchange or replace radio, if required.
NO COMPACT DISC
CHANGER OPERATION, OR
CD SKIPPING SOUND1. Faulty CD. 1. Insert known good CD and test operation.
2. Foreign material on CD. 2. Clean CD and test operation.
3. Condensation on CD or
optics.3. Allow temperature of vehicle interior to stabilize
and test operation.
4. CD changer connector
faulty.4. Check for loose or corroded CD changer
connections. Repair, if required.
5. Wiring faulty. 5. Refer to Compact Disc Changer in the
Diagnosis and Testing section of this group.
6. PCI data bus faulty. 6. Use DRB scan tool and the Diagnostic
Procedures manual to test PCI data bus. Repair,
if required.
7. CD changer faulty. 7. Refer to Compact Disc Changer in the
Diagnosis and Testing section of this group.
WJAUDIO 8A - 5
AUDIO (Continued)

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)

ANTENNA BODY & CABLE
DESCRIPTION
The antenna body and cable is secured below the
fender panel by the antenna cap nut through a
mounting hole in the of the right front fender (Fig.
2). The primary coaxial antenna cable is then routed
beneath the fender sheet metal and through a entry
hole in the right cowl side panel into the interior of
the vehicle. Inside the vehicle, the primary coaxial
cable is connected to a secondary instrument panel
antenna coaxial cable with an in-line connector that
is located behind the right kick panel. The secondary
coaxial cable is then routed behind the instrument
panel to the back of the radio.
OPERATION
The antenna body and cable connects the antenna
mast to the radio. The radio antenna is an electro-
magnetic circuit component used to capture radio fre-
quency signals that are broadcast by local
commercial radio stations in both the Amplitude
Modulating (AM) and Frequency Modulating (FM)
frequency ranges. These electromagnetic radio fre-
quency signals induce small electrical modulations
into the antenna as they move past the mast. The
antenna body transfers the weak electromagnetic
radio waves induced into the rigid antenna mast into
the center conductor of the flexible primary antenna
coaxial cable. The braided outer shield of the
antenna coaxial cable is grounded through both the
antenna body and the radio chassis, effectively
shielding the radio waves as they are conducted to
the radio. The radio then tunes and amplifies the
weak radio signals into stronger electrical signals in
order to operate the audio system speakers.
DIAGNOSIS AND TESTING - ANTENNA BODY
AND CABLE
The following four tests are used to diagnose the
antenna with an ohmmeter:
²Test 1- Mast to ground test
²Test 2- Tip-of-mast to tip-of-conductor test
²Test 3- Body ground to battery ground test
²Test 4- Body ground to antenna coaxial cable
shield test.
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 ohmmeter test lead connections for each test
are shown in the illustration (Fig. 3).
Fig. 2 Antenna Body and Cable
1 - MAST
2 - BODY & CABLE
3 - CAP NUT
4 - ADAPTER
5 - RIGHT FRONT FENDER
WJAUDIO 8A - 7