ECU DODGE RAM 2001 Service Repair Manual

Compass mini-trip computer units for vehicles
equipped with the VTSS include a red Light-Emit-
ting Diode (LED) on their electronic circuit board.
This LED protrudes through the bottom of the lens
on the front of the overhead console unit, and serves
as the security indicator lamp. Refer toSecurity
Indicator Lampin Vehicle Theft/Security Systems
for more information on this feature.
The compass mini-trip computer module contains a
central processing unit and interfaces with other
electronic modules in the vehicle on the Chrysler Col-
lision Detection (CCD) data bus network. The CCD
data bus network allows the sharing of sensor infor-
mation. This helps to reduce wire harness complexity,
reduce internal controller hardware, and reduce com-
ponent sensor current loads. At the same time, this
system provides increased reliability, enhanced diag-
nostics, and allows the addition of many new feature
capabilities.
The compass mini-trip computer provides several
electronic functions and features. Some of the func-
tions and features that the compass mini-trip com-
puter module supports and/or controls, include the
following display options:
²Compass and temperature- provides the out-
side temperature and one of eight compass readings
to indicate the direction the vehicle is facing.
²Compass and compass in degrees- provides
one of eight compass readings to indicate the direc-
tion the vehicle is facing and provides the compass
direction in degrees.
²Trip odometer (ODO)- shows the distance
travelled since the last trip computer reset.
²Average fuel economy (AVG ECO)- shows
the average fuel economy since the last trip computer
reset.
²Instant fuel economy (ECO)- shows the
present fuel economy based upon the current vehicle
distance and fuel used information.
²Distance to empty (DTE)- shows the esti-
mated distance that can be travelled with the fuel
remaining in the fuel tank. This estimated distance
is computed using the average miles-per-gallon from
the last 30 gallons of fuel used.
²Elapsed time (ET)- shows the accumulated
ignition-on time since the last trip computer reset.
²Blank screen- the compass mini-trip VFD is
turned off.
The ambient temperature sensor is hard wired to
the compass mini-trip computer module. Data input
for all other compass mini-trip computer functions,
including VFD dimming level, is received through
CCD data bus messages. The compass mini-trip com-
puter uses its internal programming and all of these
inputs to calculate and display the requested data. If
the data displayed is incorrect, perform the self-diag-nostic tests as described in this group. If these tests
prove inconclusive, the use of a DRBIIItscan tool
and the proper Diagnostic Procedures manual are
recommended for further testing of the compass
mini-trip computer module and the CCD data bus.
The compass mini-trip computer module cannot be
repaired, and is available for service only as a unit. If
faulty or damaged, the complete module must be
replaced.
OPERATION
The compass mini-trip computer only operates with
the ignition switch in the On position. When the igni-
tion switch is turned to the On position, all of the
segments in the compass mini-trip computer VFD
will be turned on for one second, then the display
will return to the last function being displayed before
the ignition was turned to the Off position. With the
ignition switch in the On position, momentarily
depressing and releasing the Step push button switch
will cause the compass-mini-trip computer to change
its mode of operation, and momentarily depressing
and releasing the U.S./Metric push button will cause
the unit to toggle between U.S. and Metric measure-
ments. While in either compass mode, depressing the
U.S./Metric push button for more than ten seconds
will toggle the display between the compass/temper-
ature and the compass/compass in degrees modes.
This compass mini-trip computer features several
functions that can be reset. If both the Step and U.S./
Metric push buttons are depressed at the same time
with the ignition switch in the On position, the trip
computer information that can be reset is reset.
Depressing and releasing the Step and U.S./Metric
push buttons at the same time for more than 100
milliseconds, but not more than one second while in
any display mode (except the compass/temperature
mode) will cause a local reset. A local reset affects
only the function currently displayed. See the Reset
Chart below for more information on this feature.
Performing a local reset while in the compass/tem-
perature mode enters the module into the compass
variance setting mode.
Depressing and releasing the Step and U.S./Metric
push buttons at the same time for more than two
seconds while in any display mode (except the com-
pass/temperature mode) will cause a global reset. A
global reset changes all of the trip computer func-
tions that can be reset.
For more information on the features and control
functions of the compass mini-trip computer, see the
owner's manual in the vehicle glove box.
BR/BEMESSAGE SYSTEMS 8M - 9
COMPASS/MINI-TRIP COMPUTER (Continued)

DIAGNOSIS & TESTING - COMPASS MINI-TRIP
COMPUTER
If the problem with the compass mini-trip com-
puter module is an inoperative security indicator
lamp, refer toSecurity Indicator Lampin Vehicle
Theft/Security Systems. If the problem with the com-
pass mini-trip computer module is an ªOCº or ªSCº in
the compass/thermometer display, refer toAmbient
Temperature Sensorin the Diagnosis and Testing
section of this group. If the problem with the com-
pass mini-trip computer module is an inaccurate or
scrambled display, refer toSelf-Diagnostic Testin
the Diagnosis and Testing section of this group. If the
problem with the compass mini-trip computer module
is incorrect Vacuum Fluorescent Display (VFD) dim-
ming levels, use a DRBtscan tool and the proper
Diagnostic Procedures manual to test for the correct
dimming message inputs being received from the
instrument cluster over the Chrysler Collision Detec-
tion (CCD) data bus. If the problem is a no-display
condition, use the following procedures. For complete
circuit diagrams, refer toOverhead Consolein the
Contents of Wiring Diagrams.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the junction block. If OK, go to Step 3. If not OK,
repair the open fused B(+) circuit to the battery as
required.
(3) Check the fused ignition switch output (run/
start) fuse in the junction block. If OK, go to Step 4.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) fuse in the junction block. If OK,
go to Step 5. If not OK, repair the open fused ignition
switch output (run/start) circuit to the ignition switch
as required.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the overhead console. Check for continuity
between the ground circuit cavities of the roof wire
harness connector for the overhead console and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit to
ground as required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
roof wire harness connector for the overhead console.
If OK, go to Step 7. If not OK, repair the open fused
B(+) circuit to the junction block fuse as required.(7) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) circuit cavity of the roof wire har-
ness connector for the overhead console. If OK, refer
toSelf-Diagnostic Testin the Diagnosis and Test-
ing section of this group for further diagnosis of the
compass mini-trip computer module and the CCD
data bus. If not OK, repair the open fused ignition
switch output (run/start) circuit to the junction block
fuse as required.
SELF-DIAGNOSTIC TEST
A self-diagnostic test is used to determine that the
compass mini-trip computer module is operating
properly electrically. Initiate the self-diagnostic test
as follows:
(1) With the ignition switch in the Off position,
simultaneously depress and hold the Step button and
the U.S./Metric button.
(2) Turn the ignition switch to the On position.
(3) Continue to hold both buttons depressed until
the compass mini-trip computer module enters the
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.
8M - 10 MESSAGE SYSTEMSBR/BE
COMPASS/MINI-TRIP COMPUTER (Continued)

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 toOverhead Consolein the Removal
and Installation section of this group for the proce-
dures.
(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 toOverhead Consolein the Removal and
Installation section of this group for the procedures.
(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.
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.
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.Fig. 7 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)

DIAGNOSIS & 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 toCompass
Mini-Trip Computerin the Diagnosis and Testing
section of this group. For complete circuit diagrams,
refer toOverhead Consolein the Contents of Wir-
ing Diagrams.
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
Sensor Circuit Testin the Diagnosis and Testing
section of this group. 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
Compass Mini-Trip Computerin the Diagnosis
and Testing section of this group. If not OK, repair
the shorted ambient temperature sensor signal cir-
cuit 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.
Fig. 8 Ambient Temperature Sensor Remove/Install
1 - HOOD
2 - SCREW
3 - SENSOR AND BRACKET
4 - WIRE HARNESS CONNECTOR
5 - HOOD LATCH STRIKER
8M - 12 MESSAGE SYSTEMSBR/BE
AMBIENT TEMP SENSOR (Continued)

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.
BR/BEMESSAGE SYSTEMS 8M - 13
AMBIENT TEMP SENSOR (Continued)

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 connectors
and 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 CTMhardware 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
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.
8N - 2 POWER LOCKSBR/BE
POWER LOCKS (Continued)

OPERATION - POWER LOCK SYSTEM
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 vehiclespeed 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.
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:
BR/BEPOWER LOCKS 8N - 3
POWER LOCKS (Continued)

and receiving the proper messages on the CCD data
bus, that the CTM is receiving the proper hard wired
inputs, and that the power lock motors are being sent
the proper hard wired outputs by the CTM.
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.
PRELIMINARY TESTS
To begin this test, note the system operation while
you actuate both the Lock and Unlock functions with
the power lock switches, the door cylinder lock switches,
and the RKE transmitter. Then, proceed as follows:
²If the entire power lock system fails to function
with the power lock switches, the door cylinder lock
switches, or the RKE transmitter, check the fused
B(+) fuse in the Junction Block (JB). If the fuse is
OK, proceed to the diagnosis of the power lock
motors. (Refer to 8 - ELECTRICAL/POWER LOCKS/
POWER LOCK MOTOR - DIAGNOSIS AND TEST-
ING).
²If the power lock system functions with both
power lock switches, and both door cylinder lock
switches, but not with the RKE transmitter, proceed
to the diagnosis of the transmitter. (Refer to 8 -
ELECTRICAL/POWER LOCKS/REMOTE KEYLESS
ENTRY TRANSMITTER - DIAGNOSIS AND TEST-
ING).
²
If the entire power lock system functions with the
RKE transmitter, and both door cylinder lock switches,
but not with one or both of the power lock switches, pro-
ceed to diagnosis of the power lock switches. (Refer to 8
- ELECTRICAL/POWER LOCKS/POWER LOCK
SWITCH - DIAGNOSIS AND TESTING).
²If the entire power lock system functions with
the RKE transmitter, and both power lock switches,
but not with one or both of the door cylinder lock
switches, proceed to diagnosis of the door cylinder
lock switches. (Refer to 8 - ELECTRICAL/POWER
LOCKS/DOOR CYLINDER LOCK SWITCH - DIAG-
NOSIS AND TESTING).
²If one power lock motor fails to operate with
both of the power lock switches, both of the door cyl-
inder lock switches and/or the RKE transmitter, pro-
ceed to diagnosis of the power lock motor. (Refer to 8
- ELECTRICAL/POWER LOCKS/POWER LOCK
MOTOR - DIAGNOSIS AND TESTING).
If the problem being diagnosed is related to one or
more of the electronic features (automatic locks, door
lock inhibit, enhanced accident response, illuminated
entry, panic mode, or RKE horn chirp), further diag-
nosis should be performed using a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
DOOR CYLINDER LOCK
SWITCH
DESCRIPTION
A door cylinder lock switch is snapped onto the
back of the key lock cylinder inside each front door of
vehicles equipped with a high-line or premium Cen-
tral Timer Module (CTM). The door cylinder lock
switch is a resistor multiplexed momentary switch
that is hard wired in series between a body ground
and the CTM through the front door wire harness.
The door cylinder lock switches are driven by the key
lock cylinders and contain three internal resistors.
One resistor is used for the neutral switch position,
one for the Lock position, and one for the Unlock
position.
The door cylinder lock switches cannot be adjusted
or repaired and, if faulty or damaged, they must be
replaced.
OPERATION
The door cylinder lock switches are actuated by the
key lock cylinder when the key is inserted in the lock
cylinder and turned to the lock or unlock positions.
The door cylinder lock switch closes a path to ground
through one of three internal resistors for the Cen-
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 & 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.
BR/BEPOWER LOCKS 8N - 5
POWER LOCKS (Continued)

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.
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.
Fig. 1 Door Cylinder Lock Switch
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)

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the
automatic day/night mirror (Fig. 2).
(3) Remove the set screw that secures the auto-
matic day/night mirror to the windshield support
button.
(4) Push the automatic day/night mirror upwards
far enough for the mounting bracket to clear the sup-
port button and remove the mirror from the wind-
shield.
INSTALLATION
(1) Install the mirror to the support button.
(2) Tighten the set screw.
(3) Reconnect the harness connector to the mirror.
(4) Reconnect the negative battery cable.
POWER MIRROR SWITCH
DESCRIPTION
Both the right and left power outside mirrors are
controlled by a single multi-function switch unit
located on and mounted to the upper flag area of the
driver side door trim panel.
OPERATION
The switch knob is rotated clockwise (right mirror
control), or counterclockwise (left mirror control) to
select the mirror to be adjusted. The switch knob is
then moved in a joystick fashion to control movement
of the selected mirror up, down, right, or left.
The power mirror switch cannot be repaired and, if
faulty or damaged, it must be replaced. The power
mirror switch knob is available for service replace-
ment.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Pull the control knob rearward to remove it
from the power mirror switch stem (Fig. 3).
Fig. 2 AUTOMATIC DAY/NIGHT MIRROR REMOVE
1 - SCREW
2 - WIRE HARNESS CONNECTOR
3 - AUTOMATIC DAY/NIGHT MIRROR
4 - SUPPORT BUTTON
Fig. 3 POWER MIRROR SWITCH REMOVE/INSTALL
1 - DOOR
2 - SWITCH
3 - DOOR TRIM PANEL
4 - KNOB
5 - NUT
8N - 12 POWER MIRRORSBR/BE
AUTOMATIC DAY / NIGHT MIRROR (Continued)