2002 DODGE RAM PCM

optional horn chirp durations (twenty or forty milli-
seconds) can also be selected.
²Illuminated Entry- This feature turns on the
courtesy lamps in the vehicle for a timed interval
(about thirty seconds) each time a valid Unlock sig-
nal has been received from the RKE transmitter.
²Panic Mode- This feature allows the vehicle
operator to cause the vehicle horn to pulse, the head-
lights to flash, and the courtesy lamps to illuminate
for about three minutes by depressing a Panic button
on the RKE transmitter. Pressing the Panic button a
second time will cancel the Panic mode. A vehicle
speed of about 24 kilometers-per-hour (15 miles-per-
hour) will also cancel the panic mode.
OPERATION
OPERATION - POWER LOCKS
All versions of the power lock system allow both
doors to be locked or unlocked electrically by operat-
ing the power lock switch on either front door trim
panel. On vehicles that are also equipped with the
optional Remote Keyless Entry (RKE) system, both
doors may also be locked or unlocked using a key in
either front door lock cylinder, or by using the RKE
transmitter. On vehicles with the RKE system, if cer-
tain features have been electronically enabled, the
locks may also be operated automatically by the
high-line or premium Central Timer Module (CTM)
based upon various other inputs. Those features and
their inputs are:
²Automatic Door Lock- If enabled, the high-
line/premium CTM will automatically lock the doors
when it receives a message from the Powertrain Con-
trol Module (PCM) indicating that the vehicle speed
is about 24 kilometers-per-hour (15 miles-per-hour)
or greater. The CTM also monitors the door ajar
switches, and will not activate the automatic door
lock feature until both doors have been closed for at
least five seconds. If this feature is enabled and a
door is opened after the vehicle is moving, the CTM
will also lock the doors five seconds after both doors
are closed.
²Central Locking- Vehicles equipped with a
high-line/premium CTM also have a resistor-multi-
plexed door cylinder lock switch mounted to the back
of the door lock cylinder within each front door. The
CTM continually monitors the input from these
switches to provide the central locking/unlocking fea-
ture. The CTM will automatically lock or unlock both
front doors when either front door is locked or
unlocked using a key.
²Door Lock Inhibit- The high-line/premium
CTM receives inputs from the key-in ignition switch,the headlamp switch, and the door ajar switches. The
logic within the CTM allows it to monitor these
inputs to provide a door lock inhibit feature. The
door lock inhibit feature prevents the power lock sys-
tem from being energized with a power lock switch
input if the driver door is open with the headlamps
on or the key still in the ignition switch. However,
the locks can still be operated with the manual door
lock button or with a key in the door lock cylinder,
and the power locks will still operate using the RKE
transmitter while the driver door is open with the
headlamps on or a key in the ignition.
²Enhanced Accident Response- If enabled,
the high-line/premium CTM provides an enhanced
accident response feature. This feature uses elec-
tronic message inputs received by the CTM from the
Airbag Control Module (ACM) to determine when an
airbag has been deployed. The CTM also monitors
the state of the power lock system and the vehicle
speed messages from the PCM in order to provide
this feature. If the airbag has been deployed and the
vehicle has stopped moving, the CTM will automati-
cally unlock the doors, prevent the doors from being
locked, and turn on the courtesy lamps inside the
vehicle. Of course, these responses are dependent
upon a functional battery and electrical circuitry fol-
lowing the impact.
All versions of the power lock system operate on
battery current received through a fused B(+) circuit
from a fuse in the Junction Block (JB) so that the
system remains functional, regardless of the ignition
switch position. Also, in both versions of the power
lock system, each power lock switch receives battery
current independent of the other. In vehicles with the
base version of the power lock system, the driver side
power lock switch receives ground through the body
wire harness. A single wire take out of the body wire
harness with an eyelet terminal connector is secured
by a ground screw to the lower left B-pillar (regular
cab, extended cab) or lower left quarter inner panel
(quad cab). The passenger side power lock switch
receives ground through the driver side power lock
switch in the base version of the power lock system.
The base version power lock switches direct the
appropriate battery current and ground feeds to the
power lock motors. In the power lock system for vehi-
cles with the RKE system, the power lock switches
direct a battery current Lock or Unlock request sig-
nal to the high-line or premium CTM, and the CTM
energizes internal relays to direct the appropriate
battery current and ground feeds to the power lock
motors.
BR/BEPOWER LOCKS 8N - 3
POWER LOCKS (Continued)

OPERATION - REMOTE KEYLESS ENTRY
SYSTEM
On vehicles with the Remote Keyless Entry (RKE)
system, the power locks can be operated remotely
using the RKE transmitter. If the vehicle is so
equipped, the RKE transmitter also arms and dis-
arms the factory-installed Vehicle Theft Security Sys-
tem (VTSS). Three small, recessed buttons on the
outside of the transmitter case labelled Lock, Unlock,
and Panic allow the user to choose the function that
is desired. The RKE transmitter then sends the
appropriate Radio Frequency (RF) signal. An RF
receiver that is integral to the high-line or premium
version of the Central Timer Module (CTM) receives
the transmitted signal, then uses its internal elec-
tronic programming to determine whether the
received signal is valid and what function has been
requested. If the signal is valid, the CTM provides
the programmed features.
Besides operating the power lock system and arm-
ing or disarming the VTSS, the RKE system also
controls the following features:
²Horn Chirp- If this feature is enabled, the
CTM provides a horn chirp by internally pulling the
control coil of the horn relay to ground through a
hard wired circuit output.
²Illuminated Entry- The CTM provides illumi-
nated entry by internally controlling the current flow
to the courtesy lamps in the vehicle through a hard
wired output circuit.
²Panic Mode- The CTM provides the horn pulse
and headlight flash by internally pulling the control
coils of the horn relay and headlamp relay to ground
through hard wired circuit outputs. The CTM con-
trols the current flow to the courtesy lamps in the
vehicle through a hard wired output circuit. The
CTM also monitors the vehicle speed through elec-
tronic messages it receives from the Powertrain Con-
trol Module (PCM) over the Chrysler Collision
Detection (CCD) data bus network.
The RKE system operates on battery current
received through a fused B(+) circuit from a fuse in
the Junction Block (JB) so that the system remains
functional, regardless of the ignition switch position.
The RKE system can retain the vehicle access codes
of up to four RKE transmitters. The transmitter
codes are retained in RKE system memory, even if
the battery is disconnected. If a transmitter is faulty
or is lost, new transmitter vehicle access codes can be
programmed into the system using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
Many of the electronic features in the vehicle con-
trolled or supported by the high-line or premium ver-
sions of the CTM are programmable using the
DRBIIItscan tool. In addition, the high-line/pre-
mium CTM software is Flash compatible, whichmeans it can be reprogrammed using Flash repro-
gramming procedures. However, if any of the CTM
hardware components are damaged or faulty, the
entire CTM unit must be replaced. The hard wired
inputs or outputs of the CTM 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 DRBIIIt
scan tool is required. Refer to the appropriate diag-
nostic information.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER LOCKS
The following tests provide a preliminary diagnosis
for the power lock system usedonlyon vehicles
equipped with a base version of the Central Timer
Module (CTM). These testsdo notapply to the diag-
nosis of the power lock system used on vehicles
equipped with the optional Remote Keyless Entry
(RKE) system, which includes a high-line or premium
CTM. (Refer to 8 - ELECTRICAL/POWER LOCKS -
DIAGNOSIS AND TESTING - POWER LOCK &
REMOTE KEYLESS ENTRY SYSTEM). 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.
PRELIMINARY TESTS
To begin this test, note the system operation while
you actuate both the Lock and Unlock functions with
the power lock switches. Then, proceed as follows:
²If the entire power lock system fails to function
with both of the power lock switches, check the fused
B(+) fuse in the Junction Block (JB). If the fuse is
OK, check the ground circuit between the driver side
power lock switch and ground (G301). If the ground
circuit is OK, proceed to the diagnosis of the power
lock motors. (Refer to 8 - ELECTRICAL/POWER
LOCKS/POWER LOCK MOTOR - DIAGNOSIS AND
TESTING).
²If the entire power lock system fails to function
with only one of the power lock switches, proceed to
diagnosis of the power lock switches. (Refer to 8 -
ELECTRICAL/POWER LOCKS/POWER LOCK
SWITCH - DIAGNOSIS AND TESTING).
²If only one power lock motor fails to operate
with both power lock switches, proceed to diagnosis
of the power lock motor. (Refer to 8 - ELECTRICAL/
POWER LOCKS/POWER LOCK MOTOR - DIAGNO-
SIS AND TESTING).
8N - 4 POWER LOCKSBR/BE
POWER LOCKS (Continued)

SPEED CONTROL
TABLE OF CONTENTS
page page
SPEED CONTROL
DESCRIPTION
DESCRIPTION - SPEED CONTROL SYSTEM . 1
DESCRIPTION - VEHICLE SPEED INPUT....2
OPERATION - SPEED CONTROL SYSTEM....2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - VACUUM
SUPPLY TEST.........................3
DIAGNOSIS AND TESTING - ROAD TEST....4
SPECIFICATIONS
TORQUE - SPEED CONTROL SYSTEM.....4
CABLE
DESCRIPTION..........................4
OPERATION............................4
REMOVAL
REMOVAL - GAS ENGINES...............4
REMOVAL - DIESEL WITH AUTO. TRANS. . . . 5
INSTALLATION
INSTALLATION - GAS ENGINES...........5
INSTALLATION - DIESEL WITH AUTO.
TRANS...............................6SPEED CONTROL SERVO
DESCRIPTION..........................6
OPERATION............................6
REMOVAL
REMOVAL............................6
REMOVAL - DIESEL WITH AUTO. TRANS. . . . 9
INSTALLATION
INSTALLATION.......................11
INSTALLATION - DIESEL WITH AUTO.
TRANS..............................12
SWITCH
DESCRIPTION.........................12
OPERATION...........................12
REMOVAL.............................13
INSTALLATION.........................14
VACUUM RESERVOIR
DESCRIPTION.........................14
REMOVAL.............................14
INSTALLATION.........................15
SPEED CONTROL
DESCRIPTION
DESCRIPTION - SPEED CONTROL SYSTEM
Gas Engines and/or Diesel With Automatic Trans.
The speed control system is operated by the use of
a cable and a vacuum controlled servo. Electronic
control of the speed control system is integrated into
the Powertrain Control Module (PCM). The controls
consist of two steering wheel mounted switches. The
switches are labeled: ON/OFF, RES/ACCEL, SET,
COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THATARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
Diesel With Manual Trans.
The speed control system is fully electronically con-
trolled by the Engine Control Module (ECM).A
cable and a vacuum controlled servo are not
used if the vehicle is equipped with a manual
transmission and a diesel engine. This is a ser-
vo-less system.The controls consist of two steering
wheel mounted switches. The switches are labeled:
ON/OFF, RES/ACCEL, SET, COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
BR/BESPEED CONTROL 8P - 1

DESCRIPTION - VEHICLE SPEED INPUT
Gas Engines and/or Diesel With Automatic Trans.
The Vehicle Speed Sensor (VSS) is no longer used
for any Dodge Truck.
Vehicle speed and distance covered are measured
by the Rear Wheel Speed Sensor. The sensor is
mounted to the rear axle. A signal is sent from this
sensor to the Controller Antilock Brake (CAB) com-
puter. A signal is then sent from the CAB to the Pow-
ertrain Control Module (PCM) to determine vehicle
speed and distance covered. The PCM will then
determine strategies for speed control system opera-
tion.
Diesel With Manual Trans.
The Vehicle Speed Sensor (VSS) is no longer used
for any Dodge Truck.
Vehicle speed and distance covered are measured
by the Rear Wheel Speed Sensor. The sensor is
mounted to the rear axle. A signal is sent from this
sensor to the Controller Antilock Brake (CAB) com-
puter. A signal is then sent from the CAB to the
Engine Control Module (ECM) to determine vehicle
speed and distance covered. The ECM will then
determine strategies for speed control system opera-
tion.
OPERATION - SPEED CONTROL SYSTEM
Gas Engines and/or Diesel With Automatic Trans.
When speed control is selected by depressing the
ON switch, the PCM allows a set speed to be stored
in PCM RAM for speed control. To store a set speed,
depress the SET switch while the vehicle is moving
at a speed between 35 and 85 mph. In order for the
speed control to engage, the brakes cannot be
applied, nor can the gear selector be indicating the
transmission is in Park or Neutral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal.
²Depressing the OFF switch.
²Depressing the CANCEL switch.
²Depressing the clutch pedal (if equipped).
NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the PCM.
For added safety, the speed control system is pro-
grammed to disengage for any of the following condi-
tions:
²An indication of Park or Neutral.
²A rapid increase of rpm (indication that the
clutch has been disengaged).²Excessive engine rpm (indicates that the trans-
mission may be in a low gear).
²The speed signal increases at a rate of 10 mph
per second (indicates that the coefficient of friction
between the road surface and tires is extremely low).
²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate).
Once the speed control has been disengaged,
depressing the RES/ACCEL switch (when speed is
greater than 30 mph) restores the vehicle to the tar-
get speed that was stored in the PCM.
While the speed control is engaged, the driver can
increase the vehicle speed by depressing the RES/AC-
CEL switch. The new target speed is stored in the
PCM when the RES/ACCEL is released. The PCM
also has a9tap-up9feature in which vehicle speed
increases at a rate of approximately 2 mph for each
momentary switch activation of the RES/ACCEL
switch.
A ªtap downº feature is used to decelerate without
disengaging the speed control system. To decelerate
from an existing recorded target speed, momentarily
depress the COAST switch. For each switch activa-
tion, speed will be lowered approximately 1 mph.
Diesel With Manual Trans.
When speed control is selected by depressing the
ON switch, the Engine Control Module (ECM) allows
a set speed to be stored in ECM RAM for speed con-
trol. To store a set speed, depress the SET switch
while the vehicle is moving at a speed between 35
and 85 mph. In order for the speed control to engage,
the brakes cannot be applied.The speed control can
be disengaged manually by:
²Stepping on the brake pedal.
²Depressing the OFF switch.
²Depressing the CANCEL switch.
²Depressing the clutch pedal.
NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the ECM.
For added safety, the speed control system is pro-
grammed to disengage for any of the following condi-
tions:
²A rapid increase of rpm (indication that the
clutch has been disengaged).
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear).
²The speed signal increases at a rate of 10 mph
per second (indicates that the coefficient of friction
between the road surface and tires is extremely low).
²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate).
8P - 2 SPEED CONTROLBR/BE
SPEED CONTROL (Continued)

INSTALLATION - DIESEL WITH AUTO. TRANS.
(1) Install (connect) end of speed control servo
cable to speed control servo. Refer to Speed Control
Servo Removal/Installation.
(2) Install cable through mounting hole on mount-
ing bracket. Cable snaps into bracket.
(3) Connect servo cable to throttle lever by push-
ing cable connector rearward onto lever pin while
holding lever forward.
(4) Connect negative battery cables to both batter-
ies.
(5) Before starting engine, operate accelerator
pedal to check for any binding.
(6) Install cable/lever cover.
SPEED CONTROL SERVO
DESCRIPTION
A speed control servo is not used if equipped
with both a diesel engine and a manual trans-
mission.
The servo unit consists of a solenoid valve body,
and a vacuum chamber. The solenoid valve body con-
tains three solenoids:
²Vacuum²Vent
²Dump
The vacuum chamber contains a diaphragm with a
cable attached to control the throttle linkage.
OPERATION
A speed control servo is not used if equipped
with both a diesel engine and a manual trans-
mission.
The Powertrain Control Module (PCM) controls the
solenoid valve body. The solenoid valve body controls
the application and release of vacuum to the dia-
phragm of the vacuum servo. The servo unit cannot
be repaired and is serviced only as a complete assem-
bly.
Power is supplied to the servo's by the PCM
through the brake switch. The PCM controls the
ground path for the vacuum and vent solenoids.
The dump solenoid is energized anytime it receives
power. If power to the dump solenoid is interrupted,
the solenoid dumps vacuum in the servo. This pro-
vides a safety backup to the vent and vacuum sole-
noids.
The vacuum and vent solenoids must be grounded
at the PCM to operate. When the PCM grounds the
vacuum servo solenoid, the solenoid allows vacuum
to enter the servo and pull open the throttle plate
using the cable. When the PCM breaks the ground,
the solenoid closes and no more vacuum is allowed to
enter the servo. The PCM also operates the vent sole-
noid via ground. The vent solenoid opens and closes a
passage to bleed or hold vacuum in the servo as
required.
The PCM duty cycles the vacuum and vent sole-
noids to maintain the set speed, or to accelerate and
decelerate the vehicle. To increase throttle opening,
the PCM grounds the vacuum and vent solenoids. To
decrease throttle opening, the PCM removes the
grounds from the vacuum and vent solenoids. When
the brake is released, if vehicle speed exceeds 30
mph to resume, 35 mph to set, and the RES/ACCEL
switch has been depressed, ground for the vent and
vacuum circuits is restored.
REMOVAL
REMOVAL
V-8 ENGINE
(1) Disconnect negative battery cable at battery.
(2) Disconnect electrical connector at servo (Fig. 4).
(3) Disconnect vacuum hose at servo.
(4) Disconnect servo cable at throttle body. Refer to
Servo Cable Removal/Installation in this group.
Fig. 3 Servo Cable at Throttle Lever
1 - PINCH (2) TABS
2 - CABLE MOUNTING BRACKET
3 - PINCH TABS (2)
4 - OFF
5 - THROTTLE CABLE
6 - THROTTLE LEVER
7 - THROTTLE LEVER PIN
8 - OFF
9 - CONNECTOR
10 - SPEED CONTROL CABLE
8P - 6 SPEED CONTROLBR/BE
CABLE (Continued)

(4) Insert servo studs through holes in servo cable
sleeve.
(5) Install servo mounting nuts and tighten to 8.5
N´m (75 in. lbs.) torque.
(6) Connect vacuum line to servo.
(7) Connect electrical connector to servo terminals.
(8) Connect servo cable to throttle body. Refer to
Servo Cable Removal/Installation in this group.
(9) Install battery tray. Tighten all battery tray
mounting hardware to 16 N´m (140 in. lbs.) torque.
(10) Position battery into battery tray.
(11) If equipped, install battery heat shield.
(12) Install battery holddown clamp. Tighten bolt
to 4 N´m (35 in. lbs.) torque.
(13) Connect positive battery cable to battery.
(14) Connect negative battery cable to battery.
(15) Before starting engine, operate accelerator
pedal to check for any binding.
INSTALLATION - DIESEL WITH AUTO. TRANS.
(1) Position servo to mounting bracket.
(2) Align hole in cable connector with hole in servo
pin. Install cable-to-servo retaining clip.
(3) Insert servo studs through holes in servo
mounting bracket.
(4) Insert servo studs through holes in servo cable
sleeve.
(5) Install servo mounting nuts and tighten to 8.5
N´m (75 in. lbs.) torque.
(6) Connect vacuum line to servo.
(7) Connect electrical connector to servo terminals.
(8) Connect servo cable to throttle lever by push-
ing cable connector rearward onto lever pin while
holding lever forward.
(9) Install battery tray. Tighten all battery tray
mounting hardware to 16 N´m (140 in. lbs.) torque.
(10) Position battery into battery tray.
(11) If equipped, install battery heat shield.
(12) Install battery holddown clamp. Tighten bolt
to 4 N´m (35 in. lbs.) torque.
(13) Connect positive battery cable to battery.
(14) Connect negative battery cables to both bat-
teries.
(15) Before starting engine, operate accelerator
pedal to check for any binding.
(16) Install cable/lever cover.
SWITCH
DESCRIPTION
Gas Engines and Diesel With Auto. Trans.
There are two separate switch pods that operate
the speed control system. The steering-wheel-
mounted switches use multiplexed circuits to provideinputs to the Powertrain Control Module (PCM) for
ON, OFF, RESUME, ACCELERATE, SET, DECEL
and CANCEL modes. Refer to the owner's manual for
more information on speed control switch functions
and setting procedures.
The individual switches cannot be repaired. If one
switch fails, the entire switch module must be
replaced.
Diesel With Manual Trans.
There are two separate switch pods that operate
the speed control system. The steering-wheel-
mounted switches use multiplexed circuits to provide
inputs to the Engine Control Module (ECM) for ON,
OFF, RESUME, ACCELERATE, SET, DECEL and
CANCEL modes. Refer to the owner's manual for
more information on speed control switch functions
and setting procedures.
The individual switches cannot be repaired. If one
switch fails, the entire switch module must be
replaced.
OPERATION
Gas Engines and Diesel With Auto. Trans.
When speed control is selected by depressing the
ON, OFF switch, the Powertrain Control Module
(PCM) allows a set speed to be stored in its RAM for
speed control. To store a set speed, depress the SET
switch while the vehicle is moving at a speed
between approximately 35 and 85 mph. In order for
the speed control to engage, the brakes cannot be
applied, nor can the gear selector be indicating the
transmission is in Park or Neutral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal.
²Depressing the OFF switch.
²Depressing the CANCEL switch.
The speed control can be disengaged also by any of
the following conditions:
²An indication of Park or Neutral.
²The vehicle speed signal increases at a rate of
10 mph per second (indicates that the co-efficient of
friction between the road surface and tires is
extremely low).
²Depressing the clutch pedal.
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear).
²The vehicle speed signal decreases at a rate of
10 mph per second (indicates that the vehicle may
have decelerated at an extremely high rate).
²If the actual speed is not within 20 mph of the
set speed.
The previous disengagement conditions are pro-
grammed for added safety.
8P - 12 SPEED CONTROLBR/BE
SPEED CONTROL SERVO (Continued)

Once the speed control has been disengaged,
depressing the ACCEL switch restores the vehicle to
the target speed that was stored in the PCM's RAM.
NOTE: Depressing the OFF switch will erase the set
speed stored in the PCM's RAM.
If, while the speed control is engaged, the driver
wishes to increase vehicle speed, the PCM is pro-
grammed for an acceleration feature. With the
ACCEL switch held closed, the vehicle accelerates
slowly to the desired speed. The new target speed is
stored in the PCM's RAM when the ACCEL switch is
released. The PCM also has a9tap-up9feature in
which vehicle speed increases at a rate of approxi-
mately 2 mph for each momentary switch activation
of the ACCEL switch.
The PCM also provides a means to decelerate with-
out disengaging speed control. To decelerate from an
existing recorded target speed, depress and hold the
COAST switch until the desired speed is reached.
Then release the switch. The ON, OFF switch oper-
ates two components: the PCM's ON, OFF input, and
the battery voltage to the brake switch, which powers
the speed control servo.
Diesel With Manual Trans.
When speed control is selected by depressing the
ON, OFF switch, the Engine Control Module (ECM)
allows a set speed to be stored in its RAM for speed
control. To store a set speed, depress the SET switch
while the vehicle is moving at a speed between
approximately 35 and 85 mph. In order for the speed
control to engage, the brakes cannot be applied.
The speed control can be disengaged manually by:
²Stepping on the brake pedal.
²Depressing the OFF switch.
²Depressing the CANCEL switch.
The speed control can be disengaged also by any of
the following conditions:
²The vehicle speed signal increases at a rate of
10 mph per second (indicates that the co-efficient of
friction between the road surface and tires is
extremely low).
²Depressing the clutch pedal.
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear).
²The vehicle speed signal decreases at a rate of
10 mph per second (indicates that the vehicle may
have decelerated at an extremely high rate).
²If the actual speed is not within 20 mph of the
set speed.The previous disengagement conditions are pro-
grammed for added safety.
Once the speed control has been disengaged,
depressing the ACCEL switch restores the vehicle to
the target speed that was stored in the ECM's RAM.
NOTE: Depressing the OFF switch will erase the set
speed stored in the ECM's RAM.
If, while the speed control is engaged, the driver
wishes to increase vehicle speed, the ECM is pro-
grammed for an acceleration feature. With the
ACCEL switch held closed, the vehicle accelerates
slowly to the desired speed. The new target speed is
stored in the ECM's RAM when the ACCEL switch is
released. The ECM also has a9tap-up9feature in
which vehicle speed increases at a rate of approxi-
mately 2 mph for each momentary switch activation
of the ACCEL switch.
The ECM also provides a means to decelerate with-
out disengaging speed control. To decelerate from an
existing recorded target speed, depress and hold the
COAST switch until the desired speed is reached.
Then release the switch. The ON, OFF switch oper-
ates two components: the ECM's ON, OFF input, and
the battery voltage to the brake switch, which powers
the speed control servo.
REMOVAL
WARNING: BEFORE BEGINNING ANY AIRBAG SYS-
TEM COMPONENT REMOVAL OR INSTALLATION,
REMOVE AND ISOLATE THE NEGATIVE (-)
CABLE(S) FROM THE BATTERY. THIS IS THE ONLY
SURE WAY TO DISABLE THE AIRBAG SYSTEM.
THEN WAIT TWO MINUTES FOR SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE FURTHER SYSTEM
SERVICE. FAILURE TO DO THIS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE INJURY.
(1) Disconnect and isolate negative battery
cable(s).
(2) Remove airbag module. Refer to 8, Restraint
Systems for procedures.
(3) Remove switch-to-steering wheel mounting
screws (Fig. 20).
(4) Remove switch.
(5) Remove electrical connector at switch.
BR/BESPEED CONTROL 8P - 13
SWITCH (Continued)

VEHICLE THEFT SECURITY
TABLE OF CONTENTS
page page
VEHICLE THEFT SECURITY
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING - VEHICLE THEFT
SECURITY SYSTEM....................3VTSS INDICATOR
DESCRIPTION..........................3
OPERATION............................3
DIAGNOSIS AND TESTING - VTSS
INDICATOR...........................4
VEHICLE THEFT SECURITY
DESCRIPTION
The Vehicle Theft Security System (VTSS) is an
available factory-installed option on this model when
it is also equipped with the high-line or premium
Central Timer Module (CTM). The VTSS is designed
to provide perimeter protection against unauthorized
use or tampering by monitoring the vehicle doors and
the ignition system. If unauthorized vehicle use or
tampering is detected, the system responds by puls-
ing the horn, flashing the headlamps, and preventing
the engine from operating.
The VTSS includes the following major compo-
nents, which are described in further detail else-
where in this service manual:
²Central Timer Module- The high-line or pre-
mium Central Timer Module (CTM) is located under
the driver side end of the instrument panel, inboard
of the instrument panel steering column opening.
The high-line or premium CTM contains a micropro-
cessor and software that allow it to provide many
electronic functions and features not available with
base version of the CTM, including the VTSS. The
CTM provides all of the proper VTSS features and
outputs based upon the monitored inputs. The CTM
circuitry monitors hard wired switch inputs, as well
as message inputs received from other vehicle elec-
tronic modules over the Chrysler Collision Detection
(CCD) data bus network. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/BODY CON-
TROL/CENTRAL TIMER MODULE -
DESCRIPTION).
²Door Ajar Switch- A door ajar switch is
located on the hinge pillar of each front door in the
vehicle. These switches provide an input to the VTSS
indicating whether the door is opened or closed.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
INTERIOR/DOOR AJAR SWITCH - DESCRIPTION).
²Door Cylinder Lock Switch- A door cylinder
lock switch is located on the back of each front door
lock cylinder. This switch provides an input to theVTSS indicating whether the system should remain
armed or be disarmed. (Refer to 8 - ELECTRICAL/
POWER LOCKS/DOOR CYLINDER LOCK SWITCH
- DESCRIPTION).
²Horn Relay- The horn relay is located in the
Power Distribution Center (PDC) in the engine com-
partment near the battery. The horn relay is nor-
mally activated by the horn switch to control the
sounding of the vehicle horn or horns. However, it
can also be activated by an output of the Central
Timer Module (CTM) to provide an audible indication
that unauthorized vehicle use or tampering has been
detected. (Refer to 8 - ELECTRICAL/HORN/HORN
RELAY - DESCRIPTION).
²Headlamp Relay- The headlamp relay (also
known as the security relay) is located in the Power
Distribution Center (PDC) in the engine compart-
ment near the battery. The headlamp relay is nor-
mally activated by the Central Timer Module (CTM)
based upon inputs from the Remote Keyless Entry
(RKE) panic mode feature. However, it can also be
activated by an output of the CTM to flash the head-
lamp low beams to provide a highly visible indication
that unauthorized vehicle use or tampering has been
detected. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/HEADLAMP RELAY - DESCRIP-
TION).
²VTSS Indicator- A red Light Emitting Diode
(LED) located on the lower surface of the overhead
console near the windshield is illuminated by an out-
put of the Central Timer Module (CTM) to indicate
the status of the VTSS. This LED is integral to the
electronic circuit board for the Compass Mini-Trip
Computer (CMTC). (Refer to 8 - ELECTRICAL/
OVERHEAD CONSOLE/COMPASS/MINI-TRIP
COMPUTER - DESCRIPTION).
The engine no-run feature of the VTSS relies upon
communication between the high-line or premium
CTM and the Powertrain Control Module (PCM) over
the Chrysler Collision Detection (CCD) data bus net-
work.
BR/BEVEHICLE THEFT SECURITY 8Q - 1