ignition DODGE RAM 2002 Service Repair Manual

(5) Reach through the glove box opening and
behind the glove box lamp and switch mounting
bracket to depress the retaining tabs on the top and
bottom of the glove box lamp and switch housing.
(6) While holding the retaining tabs depressed,
push the glove box lamp and switch unit out through
the hole in the mounting bracket on the instrument
panel glove box opening upper reinforcement.
(7) Remove the glove box lamp and switch unit
from the instrument panel.
INSTALLATION
(1) Reach through the glove box opening and
behind the glove box lamp and switch mounting
bracket to feed the instrument panel wire harness
connectors out through the hole in the glove box
lamp and switch housing mounting bracket.
(2) Position the glove box lamp and switch unit to
the instrument panel.
(3) Reconnect the instrument panel wire harness
connector to the connector receptacle on the back of
the glove box lamp and switch unit.
(4) Push the glove box lamp and switch unit into
the hole in the mounting bracket on the instrument
panel glove box opening upper reinforcement.
(5) Install the glove box onto the instrument panel.
(Refer to 23 - BODY/INSTRUMENT PANEL/GLOVE
BOX - INSTALLATION) for the procedures.
(6) Close the glove box.
(7) Reconnect the battery negative cable.
READING LAMP
DESCRIPTION
The overhead console in this vehicle is equipped
with two individual reading and courtesy lamps. The
lamp lenses are the only visible components of these
lamps. The reading and courtesy lamp lenses are
mounted in the overhead console housing between
the garage door opener storage bin and the sun-
glasses storage bin. Each lamp has its own switch,
bulb, reflector and lens; but both lamps share a com-
mon lamp housing within the overhead console.
The overhead console reading and courtesy lamps
operate on battery current that is provided at all
times, regardless of the ignition switch position. The
ground feed for the lamps is switched through the
integral reading and courtesy lamp switches or
through the door jamb switches. Each lamp is
designed and aimed to provide illumination that will
be directed only to that side of the vehicle on which
the lamp is located.The reading and courtesy lamp lenses, bulbs and
the lamp housing and reflector unit are available for
service replacement. The reading and courtesy lamp
switches, bulb holders and wiring are only available
as part of the overhead console wire harness. If
either of the lamp switches or bulb holders is faulty
or damaged, the entire overhead console wire har-
ness assembly must be replaced.
For service of the reading and courtesy lamp bulbs,
refer to the appropriate wiring information. The wir-
ing 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.
OPERATION
All reading and courtesy lamps located in the over-
head console are activated by the door jamb switches.
When all of the doors are closed, these lamps can be
individually activated by depressing the correspond-
ing lens. When any door is open, depressing the lamp
lenses to activate the lamp switches will not turn the
lamps off.
See the owner's manual in the vehicle glove box for
more information on the use and operation of the
overhead console reading and courtesy lamps.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Insert a long, narrow, flat-bladed tool between
the curved (outboard) edge of the reading and cour-
tesy lamp lens and the overhead console housing
(Fig. 5).
(3) Gently pry inward and downward against the
lens until the latch tab in the center of the outboard
edge of the reading and courtesy lamp lens is disen-
gaged from the overhead console housing.
(4) Pull firmly on the lens toward the outboard
side of the vehicle to disengage the two pivot tabs on
the inboard edge of the reading and courtesy lamp
lens are disengaged from the overhead console hous-
ing.
(5) Remove the reading and courtesy lamp lens
from the overhead console housing.
8L - 36 LAMPS/LIGHTING - INTERIORBR/BE
GLOVE BOX LAMP AND SWITCH (Continued)

using the U.S./Metric push button. The displayed
temperature is not an instant reading of conditions,
but an average temperature. It may take the ther-
mometer display several minutes to respond to a
major temperature change, such as driving out of a
heated garage into winter temperatures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the thermometer unit memory. When the ignition
switch is turned to the On position again, the ther-
mometer will display the memory temperature if the
engine coolant temperature is above about 43É C
(109É F). If the engine coolant temperature is below
about 43É C (109É F), the thermometer will display
the actual temperature sensed by the ambient tem-
perature sensor. The thermometer temperature dis-
play update interval varies with the vehicle speed;
therefore, if the temperature reading seems inaccu-
rate, drive the vehicle for at least three minutes
while maintaining a speed of 48 kilometers-per-hour
(30 miles-per-hour) or higher.
The thermometer function is supported by an
ambient temperature sensor. The sensor is mounted
outside the passenger compartment near the front
and center of the vehicle, and is hard wired to the
module. The ambient temperature sensor is available
as a separate service item.
STANDARD PROCEDURE
STANDARD PROCEDURE - COMPASS
CALIBRATION
CAUTION: Do not place any external magnets, such
as magnetic roof mount antennas, in the vicinity of
the compass. Do not use magnetic tools when ser-
vicing the overhead console.
The electronic compass unit features a self-cali-
brating design, which simplifies the calibration pro-
cedure. This feature automatically updates the
compass calibration while the vehicle is being driven.
This allows the compass unit to compensate for small
changes in the residual magnetism that the vehicle
may acquire during normal use. If the compass read-
ings appear to be erratic or out of calibration, per-
form the following calibration procedure. Also, new
service replacement compass mini-trip computer
modules must have their compass calibrated using
this procedure. Do not attempt to calibrate the com-
pass near large metal objects such as other vehicles,
large buildings, or bridges; or, near overhead or
underground power lines.
(1) Start the engine. If the compass/temperature
data is not currently being displayed, momentarily
depress and release the Step push button to stepthrough the display options until you have reached
the compass/temperature display.
(2) Depress both the U.S./Metric and the Step
push buttons at the same time for more than six sec-
onds, until ªCALº appears in the display, then release
both push buttons. The ªCALº in the display indi-
cates that the compass is in the calibration mode.
(3) Drive the vehicle on a level surface, at least
fifty feet away from large metal objects and power
lines, in all four compass directions, such as driving
around a city block several times or driving in two to
three complete circles at a slow to medium speed.
(4) When the calibration is successfully completed,
ªCALº will disappear from the display and normal
compass mini-trip computer operation will resume.
NOTE: If the ªCALº message remains in the display,
either there is excessive magnetism near the com-
pass, or the unit is faulty. Repeat the calibration
procedure at least one more time.
NOTE: If the wrong direction is still indicated in the
compass display, the area selected for calibration
may be too close to a strong magnetic field. Repeat
the calibration procedure in another location.
STANDARD PROCEDURE - COMPASS
VARIATION ADJUSTMENT
Compass variance, also known as magnetic decli-
nation, is the difference in angle between magnetic
north and true geographic north. In some geographic
locations, the difference between magnetic and geo-
graphic north is great enough to cause the compass
to give false readings. If this problem occurs, the
compass variance must be set. There are two meth-
ods that can be used to enter this information into
the compass mini-trip computer module. They are
the zone method and the direct method.
ZONE METHOD
(1) Using the Variance Settings map, find your
geographic location and note the zone number (Fig.
2).
(2) Turn the ignition switch to the On position. If
the compass/temperature data is not currently being
displayed, momentarily depress and release the Step
push button to step through the display options until
you have reached the compass/temperature display.
(3) Depress both the U.S./Metric and the Step
push buttons at the same time and hold them down
for more than 100 milliseconds, but not more than
one second. The compass mini-trip computer will
enter the variation adjustment mode and ªVARº
along with the current variance zone will appear in
the display.
8M - 4 MESSAGE SYSTEMSBR/BE
OVERHEAD CONSOLE (Continued)

(4) Momentarily depress and release the Step push
button to step through the zone numbers, until the
zone number for your geographic location appears in
the display.
(5) After five seconds, the displayed zone will auto-
matically be set in the compass mini-trip computer
module memory and normal operation will resume.
(6) Confirm that the correct directions are now
indicated by the compass.
DIRECT METHOD
(1) Turn the vehicle so it is headed in either the
north or south direction. The vehicle must be headed
within 45 degrees of north or south for this procedure
to work. The vehicle may be moving or stationary.
(2) Turn the ignition switch to the On position. If
the compass/temperature data is not currently being
displayed, momentarily depress and release the Step
push button to step through the display options until
you have reached the compass/temperature display.
(3) Depress both the U.S./Metric and the Step
push buttons at the same time and hold them down
for more than 100 milliseconds, but not more than
one second. The compass mini-trip computer will
enter the variation adjustment mode and ªVARº
along with the current variance zone will appear in
the display.
(4) Within the next five seconds, momentarily
depress and release the U.S./Metric push button. The
variance zone will automatically be set in the com-pass mini-trip computer module memory and normal
operation will resume.
(5) If the ªVARº in the display flashes twice before
the compass mini-trip computer module resumes nor-
mal operation, the new variance zone setting was not
accepted. Reorient the vehicle so it is headed within
45 degrees of north or south and repeat this proce-
dure.
STANDARD PROCEDURE - COMPASS
DEMAGNETIZING
A degaussing tool (Special Tool 6029) is used to
demagnetize, or degauss, the overhead console for-
ward mounting screw and the roof panel above the
overhead console. Equivalent units must be rated as
continuous duty for 110/115 volts and 60 Hz. They
must also have a field strength of over 350 gauss at 7
millimeters (0.25 inch) beyond the tip of the probe.
To demagnetize the roof panel and the overhead
console forward mounting screw, proceed as follows:
(1) Be certain that the ignition switch is in the Off
position, before you begin the demagnetizing proce-
dure.
(2) Connect the degaussing tool to an electrical
outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.
(3) Slowly approach the head of the overhead con-
sole forward mounting screw with the degaussing
tool connected.
Fig. 2 Variance Settings
BR/BEMESSAGE SYSTEMS 8M - 5
OVERHEAD CONSOLE (Continued)

(3) Engage the two mounting hooks on the rear of
the overhead console housing in the mounting holes
in the inner roof panel.
(4) Slide the overhead console forward far enough
to align the two latches on the front of the housing
with their receptacles in the inner roof panel.
(5) Push upward firmly and evenly on the front of
the overhead console until each of the two latches is
fully engaged in its receptacle in the inner roof panel.
(6) Close the garage door opener storage bin door.
(7) Reconnect the battery negative cable.
SPECIAL TOOLS
OVERHEAD CONSOLE SPECIAL TOOL
COMPASS/MINI-TRIP
COMPUTER
DESCRIPTION
The compass mini-trip computer is located in the
premium overhead console on models equipped with
this option. Two compass mini-trip computer units
are available. One unit is used on vehicles not
equipped with the Vehicle Theft Security System
(VTSS) option, and the other is used on vehicles with
the VTSS option. Both compass mini-trip computer
units include the electronic control module, a Vacu-
um-Fluorescent Display (VFD), a compass flux-gate
unit and two push button function switches.
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, thissystem 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
Degaussing Tool 6029
BR/BEMESSAGE SYSTEMS 8M - 9
OVERHEAD CONSOLE (Continued)

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.
DIAGNOSIS AND 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 this section. If the problem
with the compass mini-trip computer module is an
inaccurate or scrambled display, refer toCMTC Self-
Diagnostic Testin this section. If the problem with
the compass mini-trip computer module is incorrect
Vacuum Fluorescent Display (VFD) dimming levels,
use a DRBtscan tool and the proper Diagnostic Pro-
cedures manual to test for the correct dimming mes-
sage inputs being received from the instrument
cluster over the Chrysler Collision Detection (CCD)
data bus. If the problem is a no-display condition,use the following procedures. For complete circuit
diagrams, refer toOverhead Consolein the Con-
tents 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.
CMTC 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
8M - 10 MESSAGE SYSTEMSBR/BE
COMPASS/MINI-TRIP COMPUTER (Continued)

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

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)

The RKE transmitter operates on two Duracell
DL2016, Panasonic CR2016 (or equivalent) batteries.
Typical battery life is from one to two years. The
RKE transmitter cannot be repaired and, if faulty or
damaged, it must be replaced.
OPERATION
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the Remote Keyless Entry (RKE) transmitters.
DIAGNOSIS AND TESTING - REMOTE KEYLESS
ENTRY TRANSMITTER
(1) Replace the Remote Keyless Entry (RKE)
transmitter batteries. (Refer to 8 - ELECTRICAL/
POWER LOCKS/REMOTE KEYLESS ENTRY
TRANSMITTER - STANDARD PROCEDURE - RKE
TRANSMITTER BATTERIES). Test each of the RKE
transmitter functions. If OK, discard the faulty bat-
teries. If not OK, go to Step 2.
(2) Program the suspect RKE transmitter and
another known good transmitter into the RKE
receiver. (Refer to 8 - ELECTRICAL/POWER
LOCKS/REMOTE KEYLESS ENTRY TRANSMIT-
TER - STANDARD PROCEDURE - RKE TRANS-
MITTER PROGRAMMING).
(3) Test the RKE system operation with both
transmitters. If both transmitters fail to operate the
power lock system, a DRBIIItscan tool is required
for further diagnosis of the RKE system. Refer to the
appropriate diagnostic information. If the known
good RKE transmitter operates the power locks and
the suspect transmitter does not, replace the faulty
RKE transmitter.
NOTE: Be certain to perform the RKE Transmitter
Programming procedure again following this test.
This procedure will erase the access code of the
test transmitter from the RKE receiver.
STANDARD PROCEDURE
STANDARD PROCEDURE - RKE TRANSMITTER
PROGRAMMING
To program the Remote Keyless Entry (RKE)
transmitter access codes into the RKE receiver in the
high-line or premium Central Timer Module (CTM)
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
STANDARD PROCEDURE - REMOTE KEYLESS
ENTRY TRANSMITTER BATTERIES
The Remote Keyless Entry (RKE) transmitter case
snaps open and shut for battery access. To replace
the RKE transmitter batteries:
(1) Using a trim stick or a thin coin, gently pry at
the notch in the center seam of the RKE transmitter
case halves located near the key ring until the two
halves unsnap.
(2) Lift the back half of the transmitter case off of
the RKE transmitter.
(3) Remove the two batteries from the RKE trans-
mitter.
(4) Replace the two batteries with new Duracell
DL2016, or their equivalent. Be certain that the bat-
teries are installed with their polarity correctly ori-
ented.
(5) Align the two RKE transmitter case halves
with each other, and squeeze them firmly and evenly
together using hand pressure until they snap back
into place.
POWER LOCK SWITCH
DESCRIPTION
The power lock system can be controlled by a two-
way momentary switch integral to the power window
and lock switch and bezel unit on the trim panel of
each front door. Each power lock switch is illumi-
nated by a Light-Emitting Diode (LED) that is inte-
gral to the switch paddle. The LED of each switch is
illuminated whenever the ignition switch is in the
On position.
The power lock switches and their LEDs cannot be
adjusted or repaired and, if faulty or damaged, the
entire power window and lock switch and bezel unit
must be replaced.
OPERATION
On models with a base version of the Central
Timer Module (CTM), the power lock switches are
hard-wired to the power lock motors. The power lock
switch provides the correct battery and ground feeds
to the power lock motors to lock or unlock the door
latches.
On models with a high-line or premium version of
the CTM, the power lock switch controls battery cur-
rent signals to the lock and unlock sense inputs of
the CTM. The CTM then relays the correct battery
and ground feeds to the power lock motors to lock or
unlock the door latches.
8N - 8 POWER LOCKSBR/BE
REMOTE KEYLESS ENTRY TRANSMITTER (Continued)