instrument panel DODGE RAM 2002 Service Repair Manual

To protect the consumer from theft and possible
fraud the manufacturer is required to include a
Check Digit at the ninth position of the Vehicle Iden-
tification Number. The check digit is used by the
manufacturer and government agencies to verify the
authenticity of the vehicle and official documenta-
tion. The formula to use the check digit is not
released to the general public.
POSITION INTERPRETATION CODE = DESCRIPTION
1 Country of Origin 3 = Mexico
2 Make B = Dodge
3 Vehicle Type 6 = Incomplete
7 = Truck
4 Gross Vehicle Weight Rating K = 8001-9000
M = 10,001-14,000
5 Vehicle Line C = Ram Cab Chassis/Ram Pick Up
(4x2)
F = Ram Cab Chassis/Ram Pick Up
(4x4)
6 Series 2 = 2500
3 = 3500
7 Body Style 3 = Quad Cab
6 = Conventional Cab/Cab Chassis
8 Engine 6 = 5.9L 6 cyl. 24 Valve Diesel
C = 5.9 6cyl. 24 Valve Turbo Diesel
H/O
W = 8.0L 10 cyl. MPI
Z = 5.9L 8 cyl. MPI-LDC
5 = 5.9L 8cyl. MPI-HDC
9 Check Digit 0 through 9 or X
10 Model Year 2=2002
11 Plant Location M = Lago Alberto Assembly
12 thru 17 Vehicle Build Sequence
Fig. 2 Vehicle
1 - INSTRUMENT PANEL
2 - VEHICLE IDENTIFICATION NUMBER PLATE VIN
2 INTRODUCTIONBR/BE
VEHICLE IDENTIFICATION NUMBER (Continued)

²64 = Ram Truck Cab Chassis (162.7 in. Wheel
Base)
BODY CODE PLATEÐLINE 3
DIGITS 1,2, AND 3
Paint Procedure
²APA = Monotone
²AP9 = Special
²APB = Two-tone (Waterfall)
²APC = Two-tone (Centerband)
²APD = Two-tone (Lower break)
DIGIT 4
Open Space
DIGITS 5 THROUGH 8
Primary Paint
Refer to Group 23, Body for color codes.
DIGIT 9
Open Space
DIGITS 10 THROUGH 13
Secondary Paint
DIGIT 14
Open Space
DIGITS 15 THROUGH 18
Interior Trim Code
DIGIT 19
Open Space
DIGITS 20, 21, AND 22
Engine Code
²EML = 5.9 L 8 cyl. MPI Gasoline
²EMM = 5.9 L 8 cyl. MPI Gasoline (Heavy Duty)
²ETC = 5.9 L 6 cyl. Turbo Diesel
²EWA = 8.0 L 10 cyl. MPI Gasoline
BODY CODE PLATEÐLINE 2
DIGIT 1 Open Space
DIGITS 2 AND 3 Species Code. (Used for Manufacturing)
DIGIT 4
Open SpaceDIGIT 5
Market Code
²B = International
²C = Canada
²M = Mexico
²U = United States
DIGIT 6
Open Space
DIGITS 7 THROUGH 23
Vehicle Identification Number (VIN)
Refer to Vehicle Identification Number (VIN) para-
graph for proper breakdown of VIN code.
BODY CODE PLATEÐLINE 1
DIGITS 1 THROUGH 6 Body-in-white assembly sequence.
DIGIT 7
Open Space
DIGIT 8 Tailgate trim code.
DIGIT 9
Open Space
DIGITS 10 THROUGH 12 Cargo box code
²XBS = Sweptline
DIGIT 13
Open Space
DIGITS 14 THROUGH 16 Tailgate code
²MWD = Plain Tailgate
²MPB = Tailgate Applique (Black)
INTERNATIONAL VEHICLE
CONTROL & DISPLAY
SYMBOLS
DESCRIPTION - INTERNATIONAL SYMBOLS
The graphic symbols illustrated in the following
International Control and Display Symbols Chart are
used to identify various instrument controls. The
symbols correspond to the controls and displays that
are located on the instrument panel.
BR/BEINTRODUCTION 5
BODY CODE PLATE (Continued)

INSTALLATION
NOTE: If master cylinder is replaced, bleed cylinder
before installation.
(1) Install master cylinder on the booster mount-
ing studs.
(2) Install mounting nuts and tighten to 23 N´m
(17 ft. lbs.).
(3) Install brake lines and tighten to 19-23 N´m
(170-200 in. lbs.).
(4) Bleed base brake system, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL - STAN-
DARD PROCEDURE)
PARKING BRAKE
DESCRIPTION
The parking brakes are operated by a system of
cables and levers attached to a primary and second-
ary shoe positioned within the drum section of the
rotor.
The drum-in-hat design utilizes an independent set
of shoes to park the vehicle (Fig. 51).
OPERATION
To apply the parking brake the pedal is depressed.
This creates tension in the cable which pulls forward
on the park brake lever. The lever pushes the park
brake shoes outward and into contact with the drum
section of the rotor. The contact of shoe to rotor parks
the vehicle.A torsion locking mechanism is used to hold the
pedal in an applied position. Parking brake release is
accomplished by the hand release.
A parking brake switch is mounted on the parking
brake lever and is actuated by movement of the
lever. The switch, which is in circuit with the red
warning light in the dash, will illuminate the warn-
ing light whenever the parking brake is applied.
Parking brake adjustment is controlled by a cable
tensioner mechanism. The cable tensioner, once
adjusted at the factory, should not need further
adjustment under normal circumstances. Adjustment
may be required if a new tensioner, or cables are
installed, or disconnected.
PEDAL
REMOVAL
(1) Release the parking brake.
(2) Raise the vehicle.
(3) Loosen the cable tensioner nut at the equalizer
to create slack in the front cable.
(4) Lower the vehicle.
(5) Remove the knee bolster, (Refer to 23 - BODY/
INSTRUMENT PANEL/STEERING COLUMN
OPENING COVER - REMOVAL).
(6) Disconnect the brake lamp wire from the
switch on the pedal assembly.
(7) Roll the carpet back, loosen the front cable
grommet from the floorpan and the cable retainer.
(8) Disengage the cable end connector (Fig. 52)
from the arm on the pedal assembly.
Fig. 50 Master Cylinder
1 - MOUNTING NUT
2 - MOUNTING NUT
3 - BRAKE LINES
4 - MASTER CYLINDER
Fig. 51 SHOES REMOVAL
1 - PARK BRAKE SHOES
2 - ADJUSTER
3 - RETURN SPRINGS
4 - SPLASH SHIELD
5 - HOLD DOWNS
5 - 28 BRAKES - BASEBR/BE
MASTER CYLINDER (Continued)

(9) Remove the bolts/nuts from the pedal assembly
and remove the assembly.
INSTALLATION
(1) Position the replacement pedal assembly on the
dash and cowl.
(2) Install the bolts/nuts and tighten to 28 N´m (21
ft. lbs.).
(3) Connect the front cable to the arm on the pedal
assembly.
(4) Tighten the front cable grommet to the floor-
pan and the cable retainer, roll the carpet back.
(5) Connect the wires to the brake lamp switch.
(6) Install the knee bolster, (Refer to 23 - BODY/
INSTRUMENT PANEL/STEERING COLUMN
OPENING COVER - INSTALLATION).
(7) Raise the vehicle.
(8) Adjust the parking brake cable tensioner.
CABLES
REMOVAL
REMOVAL - REAR PARK BRAKE CABLE
(1) Raise and support the vehicle.
(2) Lockout the parking brake cable (Fig. 53).
(3) Loosen cable adjuster nut.
(4) Remove the rear park brake cable from the
intermediate park brake cable.(5) Compress tabs on cable end fitting on the rear
park brake cable to the frame mount bracket. Then
pull the cable through the bracket.
(6) Disengage the park brake cable from behind
the rotor assembly. (Fig. 54).
(7) Compress cable tabs on each cable end fitting
at the brake cable support plate.
(8) Remove the cables from the brake cable sup-
port plates.REMOVAL - FRONT PARKING BRAKE CABLE
(1) Raise and support vehicle.
(2) Loosen adjusting nut to create slack in front
cable.
Fig. 52 Parking Brake Pedal Assembly
1 - PARK BRAKE PEDAL
2 - FRONT CABLE
Fig. 53 LOCK OUT PARKING CABLE
1 - LOCKING PLIERS
2 - PARKING BRAKE CABLE
Fig. 54 DISENGAGEMENT OF CABLE
1 - LEVER
2 - CABLE END
BR/BEBRAKES - BASE 5 - 29
PEDAL (Continued)

(7) Install the drum in hat assembly and verify
that the rotor rotates freely without drag.
(8) Install the wheel/tire assemblies, (Refer to 22 -
TIRES/WHEELS/WHEELS - STANDARD PROCE-
DURE).
(9) Lower the vehicle enough for access to the park
brake foot pedal. Then fully apply the park brakes.
NOTE: Leave park brakes applied until adjustment
is complete.
(10) Raise the vehicle again.
(11) Mark the tensioner rod 6.35 mm (1/4 in.) from
edge of the tensioner (Fig. 56).
(12) Tighten the adjusting nut on the tensioner rod
until the mark is no longer visible.
CAUTION: Do not loosen, or tighten the tensioner
adjusting nut for any reason after completing
adjustment.
(13) Lower the vehicle until the rear wheels are
15-20 cm (6-8 in.) off the shop floor.
(14) Release the park brake foot pedal and verify
that rear wheels rotate freely without drag. Then
lower the vehicle.
RELEASE HANDLE
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Reach under the driver side outboard end of
the instrument panel to access and unsnap the plas-tic retainer clip that secures the park brake release
linkage rod to the park brake mechanism on the left
cowl side inner panel.
(3) Disengage the park brake release linkage rod
end from the park brake mechanism.
(4) Lift the park brake release handle to access
and unsnap the plastic retainer clip that secures the
park brake release linkage rod to the lever on the
back of the park brake release handle.
(5) Lower the park brake release handle and reach
under the driver side outboard end of the instrument
panel to disengage the park brake release linkage
rod end from the lever on the back of the park brake
release handle.
(6) Lift the park brake release handle to access the
handle mounting bracket.
(7) Using a trim stick or another suitable wide
flat-bladed tool, gently pry each of the park brake
release handle mounting bracket latch tabs away
from the retaining notches in the instrument panel
receptacle (Fig. 57) .
(8) With both of the park brake release handle
mounting bracket latches released, slide the handle
and bracket assembly down and out of the instru-
ment panel receptacle.
Fig. 56 Adjustment Mark
1 - TENSIONER CABLE BRACKET
2 - TENSIONER
3 - CABLE CONNECTOR
4 - 6.35mm
(1/4 IN.)
5 - ADJUSTER NUTFig. 57 Park Brake Release Handle Remove/Install
1 - CLIP
2 - ROD
3 - MOUNTING BRACKET
4 - TRIM STICK
5 - LATCH TABS
6 - PARK BRAKE RELEASE HANDLE
BR/BEBRAKES - BASE 5 - 31
CABLE TENSIONER (Continued)

INSTALLATION
(1) Position the park brake release handle to the
instrument panel.
(2) Slide the handle and bracket assembly up into
the instrument panel receptacle until both of the
park brake release handle mounting bracket latches
are engaged with the notches in the instrument
panel receptacle.
(3) Lower the park brake release handle and reach
under the driver side outboard end of the instrument
panel to engage the park brake release linkage rod
end with the lever on the back of the park brake
release handle.
(4) Lift the park brake release handle to access
and snap the plastic retainer clip that secures the
park brake release linkage rod to the lever on the
back of the park brake release handle over the link-
age rod.
(5) Reach under the driver side outboard end of
the instrument panel to access and engage the park
brake release linkage rod end to the park brake
mechanism.
(6) Snap the plastic retainer clip that secures the
park brake release linkage rod to the park brake
mechanism on the left cowl side inner panel over the
linkage rod.
(7) Reconnect the battery negative cable.
SHOES
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the disc brake caliper, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - REMOVAL)
(4) Remove the disc brake rotor, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
REMOVAL)
(5) Lockout the parking brake cable (Fig. 58).
(6) Disengage the park brake cable from behind
the rotor assembly to allow easier disassembly of the
park brake shoes (Fig. 59).
(7) Disassemble the rear park brake shoes (Fig.
60).
INSTALLATION
(1) Reassemble the rear park brake shoes (Fig.
61).
(2) Release the parking brake cable.
(3) Adjust the rear park brake shoes (Refer to 5 -
BRAKES/PARKING BRAKE/SHOES - ADJUST-
MENTS).(4) Install the disc brake rotor, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(5) Install the disc brake caliper, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - INSTALLATION).
(6) Install the tire and wheel assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(7) Lower the vehicle.
Fig. 58 LOCK OUT PARKING CABLE
1 - LOCKING PLIERS
2 - PARKING BRAKE CABLE
Fig. 59 DISENGAGEMENT OF CABLE
1 - LEVER
2 - CABLE END
5 - 32 BRAKES - BASEBR/BE
RELEASE HANDLE (Continued)

ENGINE COOLANT
THERMOSTAT - 5.9L
DESCRIPTION
CAUTION: Do not operate an engine without a ther-
mostat, except for servicing or testing.
The thermostat on the 5.9L gas powered engine is
located beneath the thermostat housing at the front
of the intake manifold (Fig. 15).
The thermostat is a wax pellet driven, reverse pop-
pet choke type.
Coolant leakage into the pellet container will cause
the thermostat to fail in the open position. Thermo-
stats very rarely stick. Do not attempt to free a ther-
mostat with a prying device.
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes longer engine
warmup time, unreliable warmup performance,
increased exhaust emissions and crankcase condensa-
tion that can result in sludge formation.
OPERATION
The wax pellet is located in a sealed container at
the spring end of the thermostat. When heated, thepellet expands, overcoming closing spring tension
and water pump pressure to force the valve to open.
DIAGNOSIS AND TESTINGÐTHERMOSTAT
ON-BOARD DIAGNOSTICS
Allgasoline powered modelsare equipped with
On-Board Diagnostics for certain cooling system com-
ponents. Refer to On-Board Diagnostics (OBD) in the
Diagnosis section of this group for additional infor-
mation. If the powertrain control module (PCM)
detects low engine coolant temperature, it will record
a Diagnostic Trouble Code (DTC) in the PCM mem-
ory. Do not change a thermostat for lack of heat as
indicated by the instrument panel gauge or by poor
heater performance unless a DTC is present. Refer to
the Diagnosis section of this group for other probable
causes. For other DTC numbers, (Refer to 25 - EMIS-
SIONS CONTROL - DESCRIPTION).
The DTC can also be accessed through the DRB
scan tool. Refer to the appropriate Powertrain Diag-
nostic Procedures information for diagnostic informa-
tion and operation of the DRB scan tool.
REMOVAL
WARNING: DO NOT LOOSEN RADIATOR DRAIN-
COCK WITH SYSTEM HOT AND PRESSURIZED.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
If thermostat is being replaced, be sure that
replacement is specified thermostat for vehicle model
and engine type.
Factory installed thermostat housings on 3.9L,
5.2L and 5.9L engines are installed on a gasket with
an anti-stick coating. This will aid in gasket removal
and clean-up.
(1) Disconnect negative battery cable at battery.
(2) Drain cooling system until coolant level is
below thermostat (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(3) Air Conditioned vehicles: Remove support
bracket (generator mounting bracket-to-intake mani-
fold) located near rear of generator (Fig. 16).
NOTE: On air conditioning equipped vehicles, the
generator must be partially removed.
(4) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL) (Fig. 17).
(5) Remove two generator mounting bolts. Do not
remove any wiring at generator. If equipped with
4WD, unplug 4WD indicator lamp wiring harness
(located near rear of generator).
Fig. 15 Thermostat - 5.9L Gas Powered Engines
1 - THERMOSTAT HOUSING
2 - GASKET
3 - INTAKE MANIFOLD
4 - THERMOSTAT
5 - MACHINED GROOVE
7 - 48 ENGINEBR/BE

ENGINE COOLANT
THERMOSTAT - 8.0L
DESCRIPTION
CAUTION: Do not operate an engine without a ther-
mostat, except for servicing or testing.
The thermostat on all gas powered engines is
located beneath the thermostat housing at the front
of the intake manifold (Fig. 22).
The thermostat is a moveable sleeve type.
Coolant leakage into the pellet container will cause
the thermostat to fail in the open position. Thermo-
stats very rarely stick. Do not attempt to free a ther-
mostat with a prying device.
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes longer engine
warmup time, unreliable warmup performance,
increased exhaust emissions and crankcase condensa-
tion that can result in sludge formation.
OPERATION
The wax pellet is located in a sealed container at
the spring end of the thermostat. When heated, the
pellet expands, overcoming closing spring tension
and water pump pressure to force the valve to open.
DIAGNOSIS AND TESTINGÐTHERMOSTAT
ON-BOARD DIAGNOSTICS
Allgasoline powered modelsare equipped with
On-Board Diagnostics for certain cooling system com-
ponents. Refer to On-Board Diagnostics (OBD) in the
Diagnosis section of this group for additional infor-
mation. If the powertrain control module (PCM)
detects low engine coolant temperature, it will record
a Diagnostic Trouble Code (DTC) in the PCM mem-
ory. Do not change a thermostat for lack of heat as
indicated by the instrument panel gauge or by poor
heater performance unless a DTC is present. Refer to
the Diagnosis section of this group for other probable
causes. For other DTC numbers, (Refer to 25 - EMIS-
SIONS CONTROL - DESCRIPTION).
The DTC can also be accessed through the DRB
scan tool. Refer to the appropriate Powertrain Diag-
nostic Procedures information for diagnostic informa-
tion and operation of the DRB scan tool.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND PRES-SURIZED. SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
If the thermostat is being replaced, be sure that
the replacement is the specified thermostat for the
vehicle model and engine type.
A rubber lip-type seal with a metal shoulder is
pressed into the intake manifold beneath the thermo-
stat (Fig. 23).
(1) Disconnect negative battery cable at battery.
(2) Drain cooling system until coolant level is
below thermostat (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(3) Remove the two support rod mounting bolts
and remove support rod (intake manifold-to-genera-
tor mount) (Fig. 24).
Fig. 22 ThermostatÐ8.0L V-10 Engine
1 - COOLANT TEMP. SENSOR (FOR PCM)
2 - HEATER SUPPLY FITTING
3 - BOLTS (6)
4 - HOUSING WITH INTEGRAL SEAL
5 - THERMOSTAT
6 - RUBBER LIP SEAL
7 - TEMP. GAUGE SENDING UNIT
BR/BEENGINE 7 - 51

AUDIO
TABLE OF CONTENTS
page page
AUDIO
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING - AUDIO..........2
SPECIAL TOOLS
AUDIO SYSTEMS......................4
ANTENNA BODY & CABLE
DESCRIPTION..........................4
OPERATION............................4
DIAGNOSIS AND TESTING - ANTENNA.......5
REMOVAL.............................6
INSTALLATION..........................6
RADIO CHOKE RELAY
DESCRIPTION..........................7
OPERATION............................8
DIAGNOSIS AND TESTING - RADIO CHOKE
RELAY...............................8
REMOVAL.............................8
INSTALLATION..........................9
INSTRUMENT PANEL ANTENNA CABLE
REMOVAL.............................9
INSTALLATION..........................9
RADIO
DESCRIPTION.........................10
OPERATION...........................10
DIAGNOSIS AND TESTING - RADIO.........10
REMOVAL.............................11
INSTALLATION.........................11
RADIO NOISE SUPPRESSION COMPONENTS
DESCRIPTION.........................12
DIAGNOSIS AND TESTING - RADIO NOISE
SUPPRESSION COMPONENTS...........12ENGINE-TO-BODY GROUND STRAP
REMOVAL.............................12
INSTALLATION.........................13
CAB-TO- BED GROUND STRAP
REMOVAL.............................13
INSTALLATION.........................14
HEATER CORE GROUND STRAP
REMOVAL.............................14
INSTALLATION.........................14
REMOTE SWITCHES
DESCRIPTION.........................14
OPERATION...........................15
DIAGNOSIS AND TESTING - REMOTE
SWITCHES..........................15
REMOVAL.............................16
INSTALLATION.........................16
SPEAKER
DESCRIPTION.........................17
OPERATION...........................17
DIAGNOSIS AND TESTING - SPEAKER......17
A-PILLAR TWEETER SPEAKER
REMOVAL.............................18
INSTALLATION.........................19
FRONT DOOR SPEAKER
REMOVAL.............................19
INSTALLATION.........................19
REAR CAB SIDE PANEL SPEAKER
REMOVAL.............................20
INSTALLATION.........................20
REAR DOOR SPEAKER
REMOVAL.............................20
INSTALLATION.........................21
AUDIO
DESCRIPTION
An audio system is standard factory-installed
equipment on this model, unless the vehicle is
ordered with an available radio delete option. The
standard equipment audio system includes an
AM/FM/cassette (RAS sales code) receiver, and
speakers in four locations. Several combinations of
radio receivers and speaker systems are offered as
optional equipment on this model. The audio system
uses an ignition switched source of battery current so
that the system will only operate when the ignition
switch is in the On or Accessory positions. The audio
system includes the following components:²Antenna
²Clockspring (with remote radio switches only)
²Filter, choke and speaker relay (with premium
speaker system only)
²High-line or premium Central Timer Module
(CTM) (with remote radio switches)
²Radio noise suppression components
²Radio receiver
²Remote radio switches (optional with RAZ radio
receiver only)
²Speakers
Refer to Electrical, Restraints for more information
on the clockspring. Refer to Electrical, Body Control/
Central Control Module for more information on the
Central Timer Module. Refer to the appropriate wir-
ing information. The wiring information includes wir-
BR/BEAUDIO 8A - 1

ing 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. Following are general descriptions of
the remaining major components in the standard and
optional factory-installed audio systems.
OPERATION
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.
CENTRAL TIMER MODULE
The high-line or premium Central Timer Module
(CTM) can also control some features of the audio
system when the vehicle is equipped with the
optional RAZ radio receiver and remote radio
switches. A high-line CTM is used on high-line ver-
sions of this vehicle. A premium CTM is used on
vehicles equipped with the optional heated seats. The
CTM combines the functions of a chime/buzzer mod-
ule, an intermittent wipe module, an illuminated
entry module, a remote keyless entry module, and a
vehicle theft security system module in a single unit.
The high-line or premium CTM also controls and
integrates many of the additional electronic functions
and features included on models with this option.
The RAZ radio receiver with a remote radio switch
option is one of the features that the CTM controls.
The CTM is programmed to send switch status mes-sages over the Chrysler Collision Detection (CCD)
data bus to control the volume, seek, and pre-set sta-
tion advance functions of the RAZ radio receiver. The
CTM monitors the status of the remote radio
switches located on the steering wheel through a
hard wired circuit. The CTM then sends the proper
switch status messages to the radio receiver. The
electronic circuitry within the radio receiver responds
to the switch status messages it receives by adjusting
the radio settings as requested.
Refer to Electrical, Body Control/Central Timer
Module for more information on the high-line CTM.
Refer to Remote Radio Switch in Description and
Operation for more information on this component.
In addition, radio receivers connected to the CCD
data bus have several audio system functions that
can be diagnosed using a DRBIIItscan tool. Refer to
the proper Diagnostic Procedures manual for more
information on DRBIIIttesting of the audio systems.
DIAGNOSIS AND TESTING - AUDIO
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Audio System Diagnosis
CONDITION POSSIBLE CAUSE CORRECTION
NO AUDIO 1. Fuse faulty. 1. Check radio fuses in junction block. Replace faulty
fuses, if required.
2. Radio connector faulty. 2. Check for loose or corroded radio connections. Repair,
if required.
3. Wiring faulty. 3. Check for battery voltage at radio connector. Repair
wiring, if required.
4. 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 Radio in the Diagnosis and Testing section of
this group.
6. Speakers faulty. 6. Refer to Speaker in the Diagnosis and Testing section
of this group.
7. Amplifier faulty (if
equipped).7. Refer to Speaker in the Diagnosis and Testing section
of this group.
8A - 2 AUDIOBR/BE
AUDIO (Continued)