service DODGE RAM 2002 Service Manual PDF
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Page 352 of 2255

Electrical, Body Control/Central Timer Module for
more information on this component.
Two rocker-type switches (Fig. 15) are mounted in
the sides of the rear (instrument panel side) steering
wheel trim cover. The switch on the left side is the
seek switch and has seek up, seek down, and preset
station advance functions. The switch on the right
side is the volume control switch and has volume up,
and volume down functions. The two switches are
retained in mounting holes located on each side of
the rear steering wheel trim cover by four latches
that are integral to the switches.
The remote radio switches share a common steer-
ing wheel wire harness with the vehicle speed control
switches. The steering wheel wire harness is con-
nected to the instrument panel wire harness through
the clockspring. Refer to Electrical, Clockspring for
more information on this component.
OPERATION
The remote radio switches are resistor multiplexed
units that are hard wired to the high-line or pre-
mium CTM through the clockspring. The CTM mon-
itors the status of the remote radio switches and
sends the proper switch status messages on the
Chrysler Collision Detection (CCD) data bus network
to the radio receiver. The electronic circuitry within
the radio is programmed to respond to these remote
radio switch status messages by adjusting the radio
settings as requested.
For diagnosis of the CTM or the CCD data bus, the
use of a DRBIIItscan tool and the proper DiagnosticProcedures manual are recommended. For more
information on the features and control functions for
each of the remote radio switches, see the owner's
manual in the vehicle glove box. For complete circuit
diagrams, refer to the appropriate wiring informa-
tion. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
DIAGNOSIS AND TESTING - REMOTE
SWITCHES
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: 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.
(1) Remove the remote radio switch(es) (Fig. 16)
from the steering wheel.
Fig. 15 Remote Radio Switches
1 - PRESET SEEK
2-UP
3 - SEEK
4 - VOLUME
5 - DOWN
Fig. 16 Remote Radio Switches
1 - WHITE REAR SWITCH
2 - BLACK REAR SWITCH
BR/BEAUDIO 8A - 15
REMOTE SWITCHES (Continued)
Page 353 of 2255

(2) Use an ohmmeter to check the switch resis-
tances as shown in the Remote Radio Switch Test
chart. If the remote radio switch resistances check
OK, go to Step 3. If not OK, replace the faulty
switch.
REMOTE RADIO SWITCH TEST
SWITCH SWITCH POSITION RESISTANCE
Right
(White)Volume Up 7320 Ohms
Right
(White)Volume Down 1210 Ohms
Left
(Black)Seek Up 4530 Ohms
Left
(Black)Seek Down 2050 Ohms
Left
(Black)Pre-Set Station
Advance10 Ohms
(3) Check for continuity between the ground cir-
cuit cavity of the remote radio switch wire harness
connector and a good ground. There should be conti-
nuity. If OK, go to Step 4. If not OK, repair the open
ground circuit to ground as required.
(4) Disconnect the 18-way wire harness connector
from the Central Timer Module (CTM). Check for
continuity between the radio control mux circuit cav-
ity of the remote radio switch wire harness connector
and a good ground. There should be no continuity. If
OK, go to Step 5. If not OK, repair the shorted radio
control mux circuit as required.
(5) Check for continuity between the radio control
mux circuit cavities of the remote radio switch wire
harness connector and the 18-way CTM wire harness
connector. There should be continuity. If OK, refer to
the proper Diagnostic Procedures manual to test the
CTM and the Chrysler Collision Detection (CCD)
data bus. If not OK, repair the open radio control
mux circuit as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the driver side airbag module from the
steering wheel. Refer to Electrical, Restraints for the
procedures.
(3) Remove the speed control switch located on the
same side of the steering wheel as the remote radio
switch that is being serviced. Refer to Electrical,
Speed Control for the procedures.
(4) Disconnect the steering wheel wire harness
connector from the connector receptacle of the remote
radio switch (Fig. 17).(5) Disengage the four remote radio switch latches
that secure the switch to the inside of the mounting
hole in the steering wheel rear trim cover.
(6) From the outside of the steering wheel rear
trim cover, remove the remote radio switch from the
trim cover mounting hole.
INSTALLATION
(1) Position the remote radio switch to the mount-
ing hole on the outside of the steering wheel rear
trim cover. Be certain that the connector receptacle is
oriented toward the bottom of the switch and pointed
toward the center of the steering wheel.
(2) Press firmly and evenly on the remote radio
switch until each of the switch latches is fully
engaged in the mounting hole of the steering wheel
rear trim cover.
(3) Reconnect the steering wheel wire harness con-
nector to the connector receptacle of the remote radio
switch.
(4) Install the speed control switch onto the steer-
ing wheel. Refer to Electrical, Speed Control for the
procedures.
Fig. 17 Remote Radio Switches Remove/Install
1 - STEERING WHEEL
2 - REMOTE RADIO SWITCH
3 - SPEED CONTROL SWITCH
4 - SCREW (2)
5 - DRIVER SIDE AIRBAG MODULE
6 - SPEED CONTROL SWITCH
7 - REAR TRIM COVER
8 - SCREW (2)
8A - 16 AUDIOBR/BE
REMOTE SWITCHES (Continued)
Page 354 of 2255

(5) Install the driver side airbag module onto the
steering wheel. Refer to Electrical, Restraints for the
procedures.
(6) Reconnect the battery negative cable.
SPEAKER
DESCRIPTION
STANDARD
The standard equipment speaker system includes
speakers in four locations. One full-range 15.2 by
22.9 centimeter (6.0 by 9.0 inch) speaker is located in
each front door. There is also one full-range 13.3 cen-
timeter (5.25 inch) diameter speaker located in each
rear cab side panel for the standard cab and the club
cab models, or in each rear door of the quad cab mod-
els.
PREMIUM
The optional premium speaker system features
Infinity model speakers in six locations. Each of the
standard front door speakers are replaced with Infin-
ity model speakers that include integral dual 30 watt
amplifiers. Each of the standard rear speakers is also
replaced by an Infinity model speaker. The premium
speaker system also includes an additional Infinity
tweeter mounted in the A-pillar garnish molding. The
total available power of the premium speaker system
is about 120 watts.
OPERATION
STANDARD
Each of the four full-range speakers used in the
standard speaker system is driven by the amplifier
that is integral to the factory-installed radio receiver.
For complete circuit diagrams, refer to the appropri-
ate 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.
PREMIUM
The Infinity speakers used in the premium speaker
system are driven by dual amplifiers that are inte-
gral to each of the front door speakers. One of these
dual amplifiers drives the front door speaker and the
A-pillar mounted tweeter for that side of the vehicle,
while the other amplifier drives the rear speaker for
that side of the vehicle. For complete circuit dia-
grams, to 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.
DIAGNOSIS AND TESTING - SPEAKER
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: 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.
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) Turn the ignition switch to the On position.
Turn the radio receiver on. Adjust the balance and
fader controls to check the performance of each indi-
vidual speaker. Note the speaker locations that are
not performing correctly. If only an Infinity A-pillar
or an Infinity rear speaker is inoperative, go to Step
8. If any other speaker is inoperative, go to Step 2.
NOTE: If the vehicle is equipped with the Infinity
premium speaker package and all of the speakers
are inoperative, refer to Filter, Choke, and Speaker
Relay in the Diagnosis and Testing section of this
group.
(2) Turn the radio receiver off. Turn the ignition
switch to the Off position. Disconnect and isolate the
battery negative cable. Remove the radio receiver
from the instrument panel. Check both the feed (+)
circuit and return (±) circuit cavities for the inopera-
tive speaker location(s) in the radio receiver wire
harness connectors for continuity to ground. In each
case, there should be no continuity. If OK, go to Step
3. If not OK, repair the shorted speaker feed (+)
and/or return (±) circuit(s) to the speaker as required.
(3) If the inoperative speaker is an Infinity-ampli-
fied speaker, go to Step 5. If the vehicle is equipped
with the standard speaker system, check the resis-
tance between the speaker feed (+) circuit and return
BR/BEAUDIO 8A - 17
REMOTE SWITCHES (Continued)
Page 360 of 2255

CHIME/BUZZER
TABLE OF CONTENTS
page page
CHIME WARNING SYSTEM
DESCRIPTION..........................1
OPERATION............................1DIAGNOSIS AND TESTING - CHIME
WARNING SYSTEM.....................2
CHIME WARNING SYSTEM
DESCRIPTION
A chime warning system is standard factory-in-
stalled equipment on this model. The chime warning
system uses a single chime tone generator that is
integral to the Central Timer Module (CTM) to pro-
vide an audible indication of various vehicle condi-
tions that may require the attention of the vehicle
operator. The chime warning system includes the fol-
lowing major components, which are described in fur-
ther detail elsewhere in this service manual:
²Central Timer Module- The Central Timer
Module (CTM) is located under the driver side end of
the instrument panel, inboard of the instrument
panel steering column opening. The CTM contains an
integral chime tone generator to provide all of the
proper chime warning system features based upon
the monitored inputs.
²Door Ajar Switch- A door ajar switch is inte-
gral to the driver side front door latch. This switch
provides an input to the chime warning system indi-
cating whether the driver side front door is open or
closed.
²Headlamp Switch- The headlamp switch is
located on the instrument panel outboard of the
steering column. The headlamp switch provides an
input to the chime warning system indicating when
the exterior lamps are turned On or Off.
²Ignition Switch- A key-in ignition switch is
integral to the ignition switch. The key-in ignition
switch provides an input to the chime warning sys-
tem indicating whether a key is present in the igni-
tion lock cylinder.
²Seat Belt Switch- A seat belt switch is inte-
gral to the driver side front seat belt buckle unit. The
seat belt switch provides an input to the chime warn-
ing system indicating whether the driver side front
seat belt is fastened.
Hard wired circuitry connects many of the chime
warning system components to each other through
the electrical system of the vehicle. These hard wired
circuits are integral to several wire harnesses, which
are routed throughout the vehicle and retained bymany different methods. These circuits may be con-
nected to each other, to the vehicle electrical system
and to the chime warning system components
through the use of a combination of soldered splices,
splice block connectors, and many different types of
wire harness terminal connectors and insulators.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
The CTM chime warning system circuitry and the
integral chime tone generator cannot be adjusted or
repaired. If the CTM or the chime tone generator are
damaged or faulty, the CTM unit must be replaced.
OPERATION
The chime warning system is designed to provide an
audible output as an indication of various conditions
that may require the attention or awareness of the
vehicle operator. The chime warning system compo-
nents operate on battery current received through a
fused B(+) fuse in the Junction Block (JB) on a non-
switched fused B(+) circuit so that the system may
operate regardless of the ignition switch position.
The chime warning system provides an audible
indication to the vehicle operator under the following
conditions:
²Fasten Seat Belt Warning- The Central
Timer Module (CTM) chime tone generator will gen-
erate repetitive chime tones at a slow rate to
announce that a hard wired input from the seat belt
switch to the Electro-Mechanical Instrument Cluster
(EMIC) indicates that the driver side front seat belt
is not fastened with the ignition switch in the On
position. Unless the driver side front seat belt is fas-
tened, the chimes will continue to sound for a dura-
tion of about seven seconds each time the ignition
switch is turned to the On position or until the driver
side front seat belt is fastened, whichever occurs
first. This chime tone is based upon a hard wired
chime request input to the CTM from the EMIC, but
is not related to the operation of the EMIC ªSeatbeltº
indicator.
BR/BECHIME/BUZZER 8B - 1
Page 361 of 2255

²Head/Park Lights-On Warning- The CTM
chime tone generator will generate repetitive chime
tones at a fast rate to announce that hard wired
inputs from the driver door ajar switch, headlamp
switch, and ignition switch indicate that the exterior
lamps are turned On with the driver side front door
opened and the ignition switch in the Off position.
The chimes will continue to sound until the exterior
lamps are turned Off, the driver side front door is
closed, or the ignition switch is turned to the On
position, whichever occurs first.
²Key-In-Ignition Warning- The CTM chime
tone generator will generate repetitive chime tones at
a fast rate to announce that hard wired inputs from
the driver door ajar switch, headlamp switch, and
ignition switch indicate that the key is in the ignition
lock cylinder with the driver side front door opened
and the ignition switch in the Off position. The
chimes will continue to sound until the key is
removed from the ignition lock cylinder, the driver
side front door is closed, or the ignition switch is
turned to the On position, whichever occurs first.
²Warning Chime Support- The CTM chime
tone generator will generate repetitive chime tones at
a slow rate to announce that a hard wired chime
request input has been received from the EMIC.
These chime tones provide an audible alert to the
vehicle operator that supplements certain visual indi-
cations displayed by the EMIC. Supplemented indica-
tions include the following:
²The ªAirbagº indicator is illuminated. The
chimes will continue to sound for a duration of about
four seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªCheck Gagesº indicator is illuminated. The
chimes will continue to sound for a duration of about
two seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªLow Fuelº indicator is illuminated. The
chimes will continue to sound for a duration of about
two seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªLow Washº indicator is illuminated. The
chimes will continue to sound for a duration of about
two seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªTrans Tempº indicator is illuminated (auto-
matic transmission only). The chimes will continue to
sound for a duration of about two seconds each time
the indicator is illuminated or until the ignition
switch is turned to the Off position, whichever occurs
first.²The vehicle is over a programmed speed value
(Middle East Gulf Coast Country (GCC) only). The
CTM chime tone generator will generate repetitive
chime tones at a slow rate to announce that the vehi-
cle speed exceeds a programmed value. The chimes
will continue to sound until the vehicle speed is
below the programmed value.
²The ªWater-In-Fuelº indicator is illuminated
(diesel engine only). The chimes will continue to
sound for a duration of about two seconds each time
the indicator is illuminated or until the ignition
switch is turned to the Off position, whichever occurs
first.
The CTM provides chime service for all available
features in the chime warning system. The CTM
relies upon hard wired inputs from the driver door
ajar switch, the EMIC, the headlamp switch, and the
key-in ignition switch (ignition switch) to provide
chime service for all of the chime warning system
features. Upon receiving the proper inputs, the CTM
activates the integral chime tone generator to pro-
vide the audible chime tone to the vehicle operator.
The chime tone generator in the CTM is capable of
producing repeated chime tones at two different
rates, slow or fast. The slow chime rate is about fifty
chime tones per minute, while the fast chime rate is
about 180 chime tones per minute. The internal pro-
gramming of the CTM and the EMIC determines the
priority of each chime tone request input that is
received, as well as the rate and duration of each
chime tone that is to be generated.
The hard wired chime warning system inputs to
the CTM and the EMIC, as well as other hard wired
circuits for this system may be diagnosed and tested
using conventional diagnostic tools and procedures.
See the owner's manual in the vehicle glove box for
more information on the features provided by the
chime warning system.
DIAGNOSIS AND TESTING - CHIME WARNING
SYSTEM
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds. The hard wired
chime warning system inputs to the Central Timer
Module (CTM) and the Electro-Mechanical Instru-
ment Cluster (EMIC), as well as other hard wired
circuits for this system may be diagnosed and tested
using conventional diagnostic tools and procedures.
8B - 2 CHIME/BUZZERBR/BE
CHIME WARNING SYSTEM (Continued)
Page 362 of 2255

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.
CHIME WARNING SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
SEAT BELT WARNING
CHIME WITH SEAT BELT
BUCKLED1. Seat belt switch sense
circuit shorted.1. Disconnect the body wire harness connector
for the seat belt switch and the instrument panel
wire harness connector (Connector C2) for the
EMIC. Check for continuity between the seat belt
switch sense circuit cavity and a good ground.
There should be no continuity. Repair the seat
belt switch sense circuit, if required.
2. Faulty seat belt switch. 2. Check for continuity between the ground circuit
cavity and the seat belt switch sense circuit cavity
of the seat belt switch connector receptacle.
There should be no continuity with the seat belt
buckled. Replace the faulty seat belt, if required.
NO SEAT BELT WARNING
CHIME WITH SEAT BELT
UNBUCKLED, BUT OTHER
CHIME FEATURES OK1. Seat belt switch ground
circuit open.1. Disconnect the body wire harness connector
for the seat belt switch. Check for continuity
between the ground circuit cavity of the connector
for the seat belt switch and a good ground. There
should be continuity. If not OK, repair the open
ground circuit to ground as required.
2. Seat belt switch sense
circuit open.2. With the body wire harness connector for the
seat belt switch and the instrument panel wire
harness connector (Connector C2) for the EMIC
disconnected, there should be continuity between
the seat belt switch sense circuit cavities of the
two connectors. Repair the seat belt switch sense
circuit, if required.
3. Faulty seat belt switch. 3. Check for continuity between the ground circuit
cavity and the seat belt switch sense circuit cavity
of the seat belt switch connector receptacle.
There should be continuity with the seat belt
unbuckled. Replace the faulty seat belt, if
required.
BR/BECHIME/BUZZER 8B - 3
CHIME WARNING SYSTEM (Continued)
Page 367 of 2255

The features that the CTM supports or controls
include the following:
²Automatic Door Lock- The high-line/premium
CTM provides an optional automatic door lock fea-
ture (also known as rolling door locks). This is a pro-
grammable feature.²Central Locking- The high-line/premium CTM
provides an optional central locking/unlocking fea-
ture.
²Chimes- All versions of the CTM provide chime
service through an integral chime tone generator.
²Courtesy Lamps- The high-line/premium CTM
provides courtesy lamp control with timed load shed-
ding.
²Door Lock Inhibit- The high-line/premium
CTM provides a door lock inhibit feature.
²Enhanced Accident Response- The high-line/
premium CTM provides an optional enhanced acci-
dent response feature. This is a programmable
feature.
²Heated Seats- The premium CTM controls the
optional heated seat system by controlling the opera-
tion of the heated seat relay.
²Illuminated Entry- The high-line/premium
CTM provides a timed illuminated entry feature.
²Intermittent Wipe Control- All versions of
the CTM provide control of the intermittent wipe
delay, and wipe-after-wash features.
²Panic Mode- The high-line/premium CTM pro-
vides support for the optional RKE system panic
mode features.
²Power Lock Control- The high-line/premium
CTM provides the optional power lock system fea-
tures, including support for the automatic door lock
and door lock inhibit modes.
²Programmable Features- The high-line/pre-
mium CTM provides support for certain programma-
ble features.
²Remote Keyless Entry- The high-line/pre-
mium CTM provides the optional Remote Keyless
Entry (RKE) system features, including support for
the RKE Lock (with optional horn chirp), Unlock,
Panic, and illuminated entry modes, as well as the
ability to be programmed to recognize up to four
RKE transmitters. The RKE horn chirp is a program-
mable feature.
²Remote Radio Switch Interface- The high-
line/premium CTM monitors and transmits the sta-
tus of the optional remote radio switches.
²Speed Sensitive Intermittent Wipe Control-
The high-line/premium CTM provides the speed sen-
sitive intermittent wipe feature.
²Vehicle Theft Alarm- The high-line/premium
CTM provides control of the optional Vehicle Theft
Alarm features, including support for the central
locking/unlocking mode.
Hard wired circuitry connects the CTM to the elec-
trical system of the vehicle. These hard wired circuits
are integral to several wire harnesses, which are
routed throughout the vehicle and retained by many
different methods. These circuits may be connected to
each other, to the vehicle electrical system and to the
Fig. 1 Central Timer Module (Base)
1 - SCREWS
2 - BRACKET
3 - WIRE HARNESS CONNECTOR
4 - CENTRAL TIMER MODULE
Fig. 2 Central Timer Module (High-Line/Premium)
1 - SCREWS
2 - BRACKET
3 - WIRE HARNESS CONNECTORS
4 - CENTRAL TIMER MODULE
8E - 2 ELECTRONIC CONTROL MODULESBR/BE
CENTRAL TIMER MODULE (Continued)
Page 368 of 2255

CTM through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
All versions of the CTM for this model are serviced
only as a complete unit. Many of the electronic fea-
tures in the vehicle controlled or supported by the
high-line or premium versions of the CTM are pro-
grammable using the DRBIIItscan tool.However, if
any of the CTM hardware components are damaged
or faulty, the entire CTM unit must be replaced. The
base version of the CTM and the hard wired inputs
or outputs of all CTM versions can be diagnosed
using conventional diagnostic tools and methods;
however, for diagnosis of the high-line or premium
versions of the CTM or the CCD data bus, the use of
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.
OPERATION
The Central Timer Module (CTM) is designed to
control and integrate many of the electronic features
and functions of the vehicle. The base version of the
CTM monitors only hard wired inputs and responds
with the proper hard wired outputs. The microproces-
sor-based high-line/premium version of the CTM
monitors many hard wired switch and sensor inputs
as well as those resources it shares with other elec-
tronic modules in the vehicle through its communica-
tion over the Chrysler Collision Detection (CCD) data
bus network. The internal programming and all of
these inputs allow the high-line/premium CTM
microprocessor to determine the tasks it needs to
perform and their priorities, as well as both the stan-
dard and optional features that it should provide.
The high-line/premium CTM programming then per-
forms those tasks and provides those features
through both CCD data bus communication with
other electronic modules and through hard wired out-
puts to a number of circuits, relays, and actuators.
These outputs allow the high-line/premium CTM the
ability to control numerous accessory systems in the
vehicle.
All versions of the CTM operate on battery current
received through fuses in the Junction Block (JB) on
a non-switched fused B(+) circuit, a fused ignition
switch output (st-run) circuit (base version only), and
a fused ignition switch output (run-acc) circuit (high-
line/premium version only). This arrangement allows
the CTM to provide some features regardless of the
ignition switch position, while other features willoperate only with the ignition switch in the Acces-
sory, On, and/or Start positions. All versions of the
CTM are grounded through their connector and take
out of the instrument panel wire harness. The high-
line/premium CTM has another ground received
through a second connector and take out of the
instrument panel wire harness. The first ground cir-
cuit receives ground through a take out with an eye-
let terminal connector of the instrument panel wire
harness that is secured by a nut to a ground stud
located on the left instrument panel end bracket,
while the second ground circuit (high-line/premium
version only) receives ground through a take out with
an eyelet terminal connector of the instrument panel
wire harness that is secured by a nut to a ground
stud located on the back of the instrument panel
armature above the inboard side of the instrument
panel steering column opening.
The high-line/premium CTM monitors its own
internal circuitry as well as many of its input and
output circuits, and will store a Diagnostic Trouble
Code (DTC) in electronic 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 CTM include the fol-
lowing:
²CCD bus± - high-line/premium version only
²CCD bus+ - high-line/premium version only
²Cylinder lock switch mux - high-line premium
version only
²Driver door ajar switch sense
²Fused B(+)
²Fused ignition switch output (run-acc) - high-
line/premium version only
²Fused ignition switch output (st-run) - base ver-
sion only
²Ground (one circuit - base version, two circuits -
high-line/premium version)
²Key-in ignition switch sense
²Passenger door ajar switch sense - high-line/pre-
mium version only
²Power door lock motor B(+) lock - high-line/pre-
mium version only
²Power door lock motor B(+) unlock - high-line/
premium version only
²Radio control mux - high-line/premium version
only
²Tone request signal
²Washer switch sense
²Wiper park switch sense
²Wiper switch mode sense
²Wiper switch mode signal
BR/BEELECTRONIC CONTROL MODULES 8E - 3
CENTRAL TIMER MODULE (Continued)
Page 369 of 2255

HARD WIRED OUTPUTS
The hard wired outputs of the CTM include the fol-
lowing:
²CCD bus± - high-line/premium version only
²CCD bus+ - high-line/premium version only
²Courtesy lamp switch output - high-line/pre-
mium version only
²Door lock driver - high-line/premium version
only
²Door unlock driver - high-line/premium version
only
²Headlamp relay control - high-line/premium ver-
sion only
²Heated seat relay control - premium version
only
²Horn relay control - high-line/premium version
only
²VTSS indicator driver - high-line/premium ver-
sion only
²Wiper motor relay control
MESSAGING
The high-line/premium CTM uses the following
messages received from other electronic modules over
the CCD data bus:
²Airbag Deploy (ACM)
²Charging System Failure (PCM)
²Engine RPM (PCM)
²System Voltage (PCM)
²Vehicle Speed (PCM)
²Voltage Fault (PCM)
The high-line/premium CTM provides the following
messages to other electronic modules over the CCD
data bus:
²Engine Enable (PCM)
²Radio Seek Up (Radio)
²Radio Seek Down (Radio)
²Radio Volume Up (Radio)
²Radio Volume Down (Radio)
²Preset Scan (Radio)
DIAGNOSIS AND TESTING - CENTRAL TIMER
MODULE
The hard wired inputs to and outputs from the
Central Timer Module (CTM) may be diagnosed and
tested using conventional diagnostic tools and meth-
ods. Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the high-line/pre-
mium CTM. In order to obtain conclusive testing of
the high-line/premium CTM, the Chrysler CollisionDetection (CCD) data bus network and all of the elec-
tronic modules that provide inputs to or receive out-
puts from the CTM must also be checked. The most
reliable, efficient, and accurate means to diagnose
the high-line/premium CTM, the CCD data bus net-
work, and the electronic modules that provide inputs
to or receive outputs from the high-line/premium
CTM requires the use of a DRBIIItscan tool and the
appropriate diagnostic information. The DRBIIIt
scan tool can provide confirmation that the CCD data
bus network is functional, that all of the electronic
modules are sending and receiving the proper mes-
sages over the CCD data bus, and that the CTM is
receiving the proper hard wired inputs and respond-
ing with the proper hard wired outputs needed to
perform its many functions.
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.
NOTE: The following tests may not prove conclu-
sive in the diagnosis of the high-line or premium
versions of the Central Timer Module (CTM). The
most reliable, efficient, and accurate means to diag-
nose the high-line or premium CTM requires the
use of a DRBIIITscan tool and the appropriate diag-
nostic information.
(1) Check the fused B(+) fuse (Fuse 13 - 10
ampere) in the Junction Block (JB). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
(Fuse 13 - 10 ampere) in the JB. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(3) For a base version CTM, check the fused igni-
tion switch output (st-run) fuse (Fuse 11 - 10 ampere)
in the JB. For a high-line/premium version CTM,
check the fused ignition switch output (run-acc) fuse
(Fuse6-25ampere) in the JB. If OK, go to Step 4. If
not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
8E - 4 ELECTRONIC CONTROL MODULESBR/BE
CENTRAL TIMER MODULE (Continued)
Page 370 of 2255

(4) Turn the ignition switch to the On position. For
a base version CTM, check for battery voltage at the
fused ignition switch output (st-run) fuse (Fuse 11 -
10 ampere) in the JB. For a high-line/premium ver-
sion CTM, check for battery voltage at the fused igni-
tion switch output (run-acc) fuse (Fuse6-25
ampere) in the JB. If OK, go to Step 5. If not OK,
repair the shorted circuit or component as required
and replace the faulty fuse.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the CTM from its mounting bracket to access
the CTM wire harness connector(s). Disconnect the
instrument panel wire harness connector(s) for the
CTM from the CTM connector receptacle(s). Check
the wire harness connectors and the CTM receptacles
for loose, corroded, or damaged terminals and pins. If
OK, go to Step 6. If not OK, repair as required.
(6) Check for continuity between the ground cir-
cuit cavity of the instrument panel wire harness con-
nector (Connector C1) for the CTM and a good
ground. For the high-line/premium version of the
CTM only, repeat the check between the ground cir-
cuit cavity of the instrument panel wire harness con-
nector (Connector C2) for the CTM and a good
ground. In each case, there should be continuity. If
OK, go to Step 7. If not OK, repair the open ground
circuit(s) to ground as required.
(7) Reconnect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
instrument panel wire harness connector (Connector
C1) for the CTM. If OK, go to Step 8. If not OK,
repair the open fused B(+) circuit between the CTM
and the JB as required.
(8) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (st-run) circuit cavity (base version) or fused
ignition switch output (run-acc) circuit cavity (high-
line/premium version) of the instrument panel wire
harness connector (Connector C1) for the CTM. If OK
with a base version CTM, replace the faulty CTM. If
OK with a high-line/premium version CTM, use a
DRBIIItscan tool and the appropriate diagnostic
information to perform further diagnosis of the CTM.
If not OK, repair the open fused ignition switch out-
put circuit between the CTM and the JB.
REMOVAL
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.
NOTE: Before replacing a high-line/premium version
Central Timer Module (CTM), use a DRBIIITscan
tool to retrieve the current settings for the CTM pro-
grammable features. Refer to the appropriate diag-
nostic information. These settings should be
duplicated in the replacement high-line/premium
CTM using the DRBIIITscan tool before returning
the vehicle to service.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(3) Remove the two screws that secure the Central
Timer Module (CTM) to the bracket on the inboard
side of the instrument panel steering column opening
(Fig. 3) or (Fig. 4).
(4) Pull the CTM into the instrument panel steer-
ing column opening far enough to access the instru-
ment panel wire harness connector(s).
Fig. 3 Central Timer Module (Base) Remove/Install
1 - SCREWS
2 - BRACKET
3 - WIRE HARNESS CONNECTOR
4 - CENTRAL TIMER MODULE
BR/BEELECTRONIC CONTROL MODULES 8E - 5
CENTRAL TIMER MODULE (Continued)