2002 DODGE RAM battery

display segment test. In this test, all of the Vacuum
Fluorescent Display (VFD) segments are lighted
while the compass mini-trip computer module per-
forms the following checks:
²Microprocessor RAM read/write test
²Non-volatile memory read/write test
²Microprocessor ROM verification test
²CCD communications test.
(4) Following completion of these tests, the com-
pass mini-trip computer will display one of three
messages: ªPASS,º ªFAIL,º or ªCCd.º Respond to the
respective test results as follows:
²If the ªPASSº message is displayed, but compass
mini-trip computer operation is still improper, the
use of a DRB scan tool and the proper Diagnostic
Procedures manual are required for further diagno-
sis.
²If the ªFAILº message is displayed, the compass
mini-trip computer module is faulty and must be
replaced.
²If the ªCCdº message is displayed, the use of a
DRBtscan tool and the proper Diagnostic Proce-
dures manual are required for further diagnosis.
²If any VFD segment should fail to light during
the display segment test, the compass mini-trip com-
puter module is faulty and must be replaced.
(5) If all tests are passed, or if the ignition switch
is turned to the Off position, the compass mini-trip
computer module will automatically return to normal
operation.
NOTE: If the compass functions, but accuracy is
suspect, it may be necessary to perform a variation
adjustment. This procedure allows the compass
unit to accommodate variations in the earth's mag-
netic field strength, based on geographic location.
Refer to Compass Variation Adjustment in the Ser-
vice Procedures section of this group.
NOTE: If the compass reading has blanked out, and
only ªCALº appears in the display, demagnetizing
may be necessary to remove excessive residual
magnetic fields from the vehicle. Refer to Compass
Demagnetizing in the Service Procedures section of
this group.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the overhead console from the head-
liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(3) Remove the three screws that secure the com-
pass mini-trip computer module to the overhead con-
sole housing (Fig. 7).(4) Pull the compass mini-trip computer module
away from the overhead console far enough to access
the wire harness connector.
(5) Disconnect the overhead console wire harness
connector from the compass mini-trip computer mod-
ule connector receptacle.
(6) Remove the compass mini-trip computer mod-
ule from the overhead console housing.
INSTALLATION
(1) Position the compass mini-trip computer mod-
ule onto the overhead console housing.
(2) Reconnect the overhead console wire harness
connector to the compass mini-trip computer module
connector receptacle.
(3) Install and tighten the three screws that secure
the compass mini-trip computer module to the over-
head console housing. Tighten the screws to 2.2 N´m
(20 in. lbs.).
(4) Install the overhead console onto the headliner
(Refer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
INSTALLATION).
(5) Reconnect the battery negative cable.
NOTE: If a new compass mini-trip computer has
been installed, the compass will have to be cali-
brated and the variance set. Refer to Compass Vari-
ation Adjustment and Compass Calibration in the
Service Procedures section of this group for the
procedures.
Fig. 7 Overhead Console Compass Mini-Trip
Computer
1 - WIRE HARNESS CONNECTOR
2 - SCREWS (3)
3 - COMPASS MINI-TRIP COMPUTER MODULE
4 - FRONT LATCHES
BR/BEMESSAGE SYSTEMS 8M - 11
COMPASS/MINI-TRIP COMPUTER (Continued)

AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the com-
pass mini-trip computer module through the ambient
temperature sensor. The ambient temperature sensor
is a variable resistor mounted to a bracket that is
secured with a screw to the underside of the hood
panel near the hood latch striker in the engine com-
partment (Fig. 8).
For complete circuit diagrams, refer toOverhead
Consolein the Contents of Wiring Diagrams. The
ambient temperature sensor cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the compass mini-trip computer module.
The resistance in the sensor changes as temperature
changes, changing the return circuit voltage to the
compass mini-trip computer module. Based upon the
resistance in the sensor, the compass mini-trip com-
puter module senses a specific voltage on the return
circuit, which it is programmed to correspond to a
specific temperature.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, and a
portion of the compass mini-trip computer module. If
any portion of the ambient temperature sensor cir-
cuit fails, the compass/thermometer display function
will self-diagnose the circuit. If 55É C (131É F)
appears in the display, the sensor is being exposed to
temperatures above 55É C (131É F), or the sensor cir-
cuit is shorted. If ±40É C (±40É F) appears in the dis-
play, the sensor is being exposed to temperatures
below ±40É C (±40É F), or the sensor circuit is open.
The ambient temperature sensor circuit can also be
diagnosed using the following Sensor Test, and Sen-
sor Circuit Test. If the temperature sensor and cir-
cuit are confirmed to be OK, but the temperature
display is inoperative or incorrect, refer toDiagnosis
and Testing the Compass Mini-Trip Computer.
For complete circuit diagrams, refer toWiring Dia-
grams.
SENSOR TEST
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.(2) Measure the resistance of the ambient temper-
ature sensor. At ±40É C (±40É F), the sensor resis-
tance is 336 kilohms. At 55É C (131É F), the sensor
resistance is 2.488 kilohms. The sensor resistance
should read between these two values. If OK, refer to
theSensor Circuit Test below. If not OK, replace
the faulty ambient temperature sensor.
SENSOR CIRCUIT TEST
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the overhead console wire har-
ness connector.
(2) Connect a jumper wire between the two termi-
nals in the body half of the ambient temperature sen-
sor wire harness connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the roof wire harness overhead con-
sole connector. There should be continuity. If OK, go
to Step 4. If not OK, repair the open sensor return
circuit or ambient temperature sensor signal circuit
to the ambient temperature sensor as required.
(4) Remove the jumper wire from the body half of
the ambient temperature sensor wire harness con-
nector. Check for continuity between the sensor
return circuit cavity of the roof wire harness over-
head console connector and a good ground. There
should be no continuity. If OK, go to Step 5. If not
OK, repair the shorted sensor return circuit as
required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the roof wire
harness overhead console connector and a good
ground. There should be no continuity. If OK, refer to
Diagnosis and Testing the Compass Mini-Trip
Computerin this section. If not OK, repair the
shorted ambient temperature sensor signal circuit as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Locate the ambient temperature sensor, on the
underside of the hood near the hood latch striker
(Fig. 8).
(3) Disconnect the wire harness connector from the
ambient temperature sensor connector receptacle.
(4) Remove the one screw that secures the ambient
temperature sensor bracket to the inner hood rein-
forcement.
(5) Remove the ambient temperature sensor from
the inner hood reinforcement.
8M - 12 MESSAGE SYSTEMSBR/BE

INSTALLATION
(1) Position the ambient temperature sensor onto
the inner hood reinforcement.
(2) Install and tighten the one screw that secures
the ambient temperature sensor bracket to the inner
hood reinforcement. Tighten the screw to 5.6 N´m (50
in. lbs.).
(3) Reconnect the wire harness connector to the
ambient temperature sensor connector receptacle.
(4) Reconnect the battery negative cable.
Fig. 8 Ambient Temperature Sensor Remove/Install
1 - HOOD
2 - SCREW
3 - SENSOR AND BRACKET
4 - WIRE HARNESS CONNECTOR
5 - HOOD LATCH STRIKER
BR/BEMESSAGE SYSTEMS 8M - 13
AMBIENT TEMP SENSOR (Continued)

Both versions of the power lock system include the
following major components, which are described in
further detail elsewhere in this service manual:
²Power Lock Motors- A reversible electric
motor integral to the door latch of each front door
locks or unlocks the front door latch when provided
with the appropriate electrical inputs.
²Power Lock Switches- A power lock switch
integral to the power window/lock switch unit located
near the forward end of the arm rest on each front
door trim panel allows the power door lock system to
be operated by either the driver or the front seat pas-
senger.
On those models equipped with the optional RKE
system, the power lock system also includes the fol-
lowing components, which are described in further
detail elsewhere 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 the many
electronic functions and features not available with
base version of the power lock system.
²Door Cylinder Lock Switches- A resistor-
multiplexed switch located on the back of each front
door lock cylinder allows the power door lock system
to be operated using a key inserted in either the
driver or passenger front door lock cylinder.
Some of the additional features of the power lock
system found in vehicles with the RKE system option
include:
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.
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.
Hard wired circuitry connects the power lock sys-
tem components to the electrical system of the vehi-
cle. 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 power lock sys-
tem components through the use of a combination of
soldered splices, splice block connectors, and many
different types of wire harness terminal connectorsand insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
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, which
means 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 power lock
system components and the hard wired inputs or out-
puts 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 DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
DESCRIPTION - REMOTE KEYLESS ENTRY
SYSTEM
A Remote Keyless Entry (RKE) system is an avail-
able option on this model. The Remote Keyless Entry
(RKE) system is a Radio Frequency (RF) system that
allows the remote operation of the power lock system
and, if the vehicle is so equipped, the Vehicle Theft
Security System (VTSS). (Refer to 8 - ELECTRICAL/
VEHICLE THEFT SECURITY - DESCRIPTION).
The RKE system 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, an RF receiver, and the software that allow it
to provide the many electronic functions and features
of the RKE system.
²Keyless Entry Transmitter- The keyless
entry transmitter is a small, battery-powered, RF
transmitter that is contained within a molded plastic
case that is designed to also serve as a convenient
key fob.
Some additional features of the RKE system
include:
²Horn Chirp- This feature provides a short,
sharp chirp of the vehicle horn to give an audible
confirmation that a valid Lock signal has been
received from the RKE transmitter. This feature can
be enabled or disabled and, if enabled, one of two
8N - 2 POWER LOCKSBR/BE
POWER LOCKS (Continued)

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)

tral Timer Module (CTM) when the front door key
lock cylinder is in the Lock, Unlock, or Neutral posi-
tions. The CTM reads the switch status through an
internal pull-up, then uses this information as an
input for both power lock system and Vehicle Theft
Security System (VTSS) operation.
The door cylinder lock switches and circuits can be
diagnosed using conventional diagnostic tools and
methods.
DIAGNOSIS AND TESTING - DOOR CYLINDER
LOCK SWITCH
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.
(1) Disconnect the door cylinder lock switch pigtail
wire connector from the door wire harness connector.
(2) Using an ohmmeter, perform the switch resis-
tance checks between the two cavities of the door cyl-
inder lock switch pigtail wire connector. Actuate the
switch by rotating the key in the door lock cylinder
to test for the proper resistance values in each of the
three switch positions, as shown in the Door Cylinder
Lock Switch chart.
DOOR CYLINDER LOCK SWITCH
Switch Position
Resistance
Driver Side Passenger Side
Neutral Neutral 12 Kilohms
Lock (Clockwise)Lock (Counter
Clockwise)644 Ohms
Unlock (Counter
Clockwise)Unlock
(Clockwise)1565 Ohms
(3) If a door cylinder lock switch fails any of the
resistance tests, replace the faulty switch as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the door outside latch handle mount-
ing hardware and linkage from the inside of the door.
(Refer to 23 - BODY/DOOR - FRONT/EXTERIOR
HANDLE - REMOVAL).
(3) From the outside of the door, pull the door out-
side latch handle out from the door far enough to
access the door cylinder lock switch (Fig. 1).
(4) Disengage the door cylinder lock switch from
the back of the lock cylinder.(5) Disconnect the door cylinder lock switch pigtail
wire connector from the door wire harness connector.
(6) Disengage the retainers that secure the door
cylinder lock switch pigtail wire harness to the inner
door panel.
(7) Remove the door cylinder lock switch from the
door.
INSTALLATION
(1) Position the door cylinder lock switch into the
door (Fig. 1).
(2) Engage the retainers that secure the door cyl-
inder lock switch pigtail wire harness to the inner
door panel.
(3) Reconnect the door cylinder lock switch pigtail
wire connector to the door wire harness connector.
(4) Reinstall the door cylinder lock switch onto the
back of the lock cylinder.
(5) Reinstall the door outside latch handle mount-
ing hardware and linkage on the inside of the door.
(Refer to 23 - BODY/DOOR - FRONT/EXTERIOR
HANDLE - INSTALLATION).
(6) Reconnect the battery negative cable.
Fig. 1 Door Cylinder Lock Switch - Typical
1 - DOOR OUTSIDE LATCH HANDLE
2 - DOOR
3 - DOOR CYLINDER LOCK SWITCH
4 - CONNECTOR
5 - RETAINERS
8N - 6 POWER LOCKSBR/BE
DOOR CYLINDER LOCK SWITCH (Continued)

POWER LOCK MOTOR
DESCRIPTION
Models equipped with the optional power lock sys-
tem have a power operated door locking mechanism
located within each front door. The lock mechanisms
are actuated by a reversible electric power lock motor
that is integral to the door latch unit within each
front door. A single short pigtail wire with a molded
plastic connector insulator connects the door lock
motor to the vehicle electrical system through a take
out and connector of each front door wire harness.
The power lock motors cannot be adjusted or
repaired and, if faulty or damaged, the entire door
latch unit must be replaced.
OPERATION
On models with a base version of the Central
Timer Module (CTM), the power lock motor is con-
trolled by the battery and ground feeds from the
power lock switches. On models with the high-line or
premium versions of the CTM, the power lock motor
is controlled by the battery and ground feeds from
the power lock and unlock relays, which are integral
and internal to the high-line and premium versions
of the CTM. A positive and negative battery connec-
tion to the two motor terminals will cause the power
lock motor plunger to move in one direction. Revers-
ing the current through these same two connections
will cause the power lock motor plunger to move in
the opposite direction.
The power lock motors and circuits can be tested
using conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - POWER LOCK
MOTOR
On models with a base version of the Central
Timer Module (CTM), confirm proper power lock
switch operation before you proceed with this diagno-
sis. On models with a high-line or premium version
of the CTM, confirm proper power lock switch, power
lock switch output circuit, and CTM operation before
you proceed with this diagnosis. Remember, the
power lock switch controls the output to the power
lock motors on models with a base CTM, while the
CTM controls the output to the power lock motors on
models with a high-line or premium CTM. Refer to
the appropriate wiring information. The wiring infor-
mation 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 con-
nectors, splices and grounds.
(1) Check each power lock motor for correct opera-
tion while moving the power lock switch to both theLock and Unlock positions. If both of the power lock
motors are inoperative, go to Step 2. If one power
lock motor is inoperative, go to Step 3.
(2) If both of the power lock motors are inopera-
tive, the problem may be caused by one shorted
motor. Disconnecting a shorted power lock motor
from the power lock circuit will allow the good power
lock motors to operate. Disconnect the wire harness
connector from each power lock motor, one at a time,
and recheck both the lock and unlock functions by
operating the power lock switch. If both power lock
motors are still inoperative after the above test,
check for a short or open circuit between the power
lock motors and either the power lock switch (base
CTM) or the CTM (high-line or premium CTM). If
disconnecting one power lock motor causes the other
motor to become functional, go to Step 3 to test the
disconnected motor.
(3) Once it is determined which power lock motor
is inoperative, that motor can be tested as follows.
Disconnect the door wire harness connector from the
inoperative power lock motor. Apply 12 volts to the
lock and unlock driver circuit cavities of the power
lock motor pigtail wire connector to check its opera-
tion in one direction. Reverse the polarity to check
the motor operation in the opposite direction. If OK,
repair the shorted or open circuits between the power
lock motor and the power lock switch (base CTM) or
the CTM (high-line or premium CTM) as required. If
not OK, replace the faulty power lock motor.
REMOTE KEYLESS ENTRY
TRANSMITTER
DESCRIPTION
The Remote Keyless Entry (RKE) system Radio
Frequency (RF) transmitter is equipped with three
buttons, labeled Lock, Unlock, and Panic. It is also
equipped with a key ring and is designed to serve as
a key fob. The operating range of the transmitter
radio signal is up to 7 meters (23 feet) from the RKE
receiver. The RKE receiver is integral to the high-
line or premium Central Timer Module (CTM) in this
vehicle.
Each RKE transmitter has a different vehicle
access code, which must be programmed into the
memory of the RKE receiver in the vehicle in order
to operate the RKE system. The RKE receiver can
retain the access codes for up to four transmitters in
its memory. (Refer to 8 - ELECTRICAL/POWER
LOCKS/REMOTE KEYLESS ENTRY TRANSMIT-
TER - STANDARD PROCEDURE - RKE TRANS-
MITTER PROGRAMMING).
BR/BEPOWER LOCKS 8N - 7