wiring CHRYSLER VOYAGER 2004 Service Manual
[x] Cancel search | Manufacturer: CHRYSLER, Model Year: 2004, Model line: VOYAGER, Model: CHRYSLER VOYAGER 2004Pages: 2585, PDF Size: 62.54 MB
Page 545 of 2585

INSTALLATION
(1) Install mounting nuts.
(2) Reconnect the wire harness to the fog lamp
bulb.
(3) Reconnect the battery negative cable.
HEADLAMP
DIAGNOSIS AND TESTING - HEADLAMP
When a vehicle experiences problems with the
headlamp system, verify the condition of the battery
connections, fuses, charging system, headlamp bulbs,
wire connectors, relay, high beam switch, dimmer
switch, and headlamp switch. Refer to the appropri-
ate wiring information.Each vehicle is equipped with various lamp assem-
blies. A good ground is necessary for proper lighting
operation. Grounding is provided by the lamp socket
when it comes in contact with the metal body, or
through a separate ground wire.
When changing lamp bulbs check the socket for
corrosion. If corrosion is present, clean it with a wire
brush.
When it is necessary to remove components to ser-
vice another, it should not be necessary to apply
excessive force or bend a component to remove it.
Before damaging a trim component, verify hidden
fasteners or captured edges are not holding the com-
ponent in place.
Fig. 10 FOG LAMP UNIT ALIGNMENT - EXPORT
1 - HIGH INTENSITY AREA 4 - 200 MM
2 - CENTER OF VEHICLE 5 - 10 METERS
3 - HORIZONTAL CENTER OF FOG LAMP UNIT 6 - FRONT OF FOG LAMP UNIT
8L - 10 LAMPS/LIGHTING - EXTERIORRS
FRONT FOG LAMP UNIT (Continued)
Page 546 of 2585

HEADLAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING
OR IGNITION TURNED
OFF.1. Loose or corroded battery
cables.1. Clean and secure battery cable clamps and
posts.
2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system, refer to
Electrical, Charging
4. Battery has insufficient charge. 4. Test battery state-of-charge, refer to
Electrical, Battery System.
5. Battery is sulfated or shorted. 5. Load test battery, refer to Electrical, Battery
System.
6. Poor lighting circuit Z343/Z344-
ground.6. Test for voltage drop across Z343/Z344-
ground locations, refer to Electrical, Wiring
Diagram Information.
HEADLAMP BULBS
BURN OUT
FREQUENTLY.1. Integrated Power Module (IPM)
not controlling voltage.1. Test and repair Integrated Power Module.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and splices.
Refer to Electrical, Wiring Information.
HEADLAMPS ARE DIM
WITH ENGINE
RUNNING ABOVE IDLE.1. Charging system output too low. 1. Test and repair charging system, refer to
Electrical, Wiring Information.
2. Poor lighting circuit Z343/Z344-
ground.2. Test for voltage drop across Z343/Z344-
ground locations, refer to Electrical, Wiring
Information.
3. High resistance in headlamp
circuit.3. Test amperage draw of headlamp circuit.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z343/Z344-
ground.1. Test for voltage drop across Z343/Z344-
ground locations, refer to Electrical, Wiring
Information.
2. Variable resistance in headlamp
circuit.2. Test amperage draw of headlamp circuit.
3. Loose or corroded terminals or
splices in circuit.3. Inspect and repair all connectors and splices,
refer to Electrical, Wiring Information.
4. Faulty headlamp switch. 4. Replace headlamp switch.
RSLAMPS/LIGHTING - EXTERIOR8L-11
HEADLAMP (Continued)
Page 547 of 2585

CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS DO NOT
ILLUMINATE.1. No voltage to headlamps. 1. Repair open headlamp circuit, refer to
Electrical, Wiring Information.
2. No Z343/Z344-ground at
headlamps.2. Repair circuit ground, refer to Electrical,
Wiring Information.
3. Broken connector terminal or
wire splice in headlamp circuit.3. Repair connector terminal or wire splice.
4. Faulty or burned out bulb. 4. Replace headlamp bulb(s).
5. Body Control Module
malfunction.5. Refer to appropriate Body Control Module
diagnostics.
6. PCI Bus Communication 6. Verify messages being transmitted by BCM
and received by FCM.
7. IPM/FCM Malfunction. 7. Refer to appropriate IPM/FCM diagnostics.
HEADLAMPS ON WITH
IGNITION IN RUN, WITH
HEADLAMP SWITCH
OFF.1. Faulty headlamp switch. 1. Replace headlamp switch (review BCM
logged faults).
2. Diagnostic tool indicates (4.7 -
5.0V) on headlamp switch input to
BCM.2. Inspect and repair terminals, connectors and
open circuits.
3. PCI Bus Communication. 3. Verify messages being transmitted by BCM
and received by FCM.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove headlamp unit retaining screws.
(3) Remove headlamp unit to expose back of unit.
(4) Remove wiring connector from bulb.
(5) Rotate headlamp bulb retaining ring counter-
clockwise.(6) Pull headlamp bulb and remove from headlamp
unit (Fig. 11).
INSTALLATION
(1) Install headlamp bulb to the headlamp unit.
(2) Install headlamp bulb retaining ring.
(3) Connect wiring connector to bulb.
(4) Install the headlamp unit.
(5) Install headlamp unit retaining screws.
(6) Reconnect the battery negative cable.
HEADLAMP SWITCH
DIAGNOSIS AND TESTING - HEADLAMP
SWITCH
Using a Digital Multi-meter, perform the HEAD-
LAMP SWITCH CONTINUITY test and refer to (Fig.
12).
If the Headlamp Switch is not within specifications
replace the switch.
Fig. 11 HEADLAMP
1 - HEADLAMP
2 - HEADLAMP UNIT
8L - 12 LAMPS/LIGHTING - EXTERIORRS
HEADLAMP (Continued)
Page 548 of 2585

HEADLAMP SWITCH CONTINUITY
HEADLAMP
SWITCH
POSITION13-WAY
CONNECTOR
TERMINALRESISTANCE
OFF 11 TO 6 3651 - 3729V
PARKING
LAMPS ON11 TO 6 1697 - 2517V
PARKING
LAMPS WITH
FRONT FOG
LAMPS ON11 TO 6 5765 - 5886V
HEADLAMPS
ON11 TO 6 788 - 809V
AUTO ON 11 TO 6 10056 - 10264V
HEADLAMPS
ON WITH
FRONT FOG
LAMPS11 TO 6 1171 - 1200V
AUTO ON WITH
FRONT FOG
LAMPS ON11 TO 6 24278 - 24773V
DIMMER
POSITION13-WAY
CONNECTOR
TERMINALRESISTANCE
DOME 12 TO 6 15568 - 23357V
PARADE 12 TO 6 5168 - 7757V
DIM HIGH 12 TO 6 2288 - 3437V
DIM LOW 12 TO 6 688 - 1037V
OFF 12 TO 6 240 - 365V
REMOVAL
(1) Disconnect and isolate the battery negative
cable.(2) Remove the Instrument Panel Lower Steering
Column Cover. Refer to Body, Instrument Panel,
Lower Steering Column Cover, Removal.
(3) Reach up behind the left side of the instrument
panel and depress spring clip on top or bottom of
headlamp switch. Firmly push out on the headlamp
switch assembly.
(4) Disconnect the wiring connectors.
(5) Remove switch from vehicle.
INSTALLATION
(1) Connect the wiring connectors.
(2) Place headlamp switch assembly into position
and firmly snap into place.
(3) Install the Instrument Panel Lower Steering
Column Cover. Refer to Body, Instrument Panel,
Lower Steering Column Cover, Installation.
(4) Connect the battery negative cable.
HEADLAMP UNIT
STANDARD PROCEDURE
STANDARD PROCEDURE - HEADLAMP UNIT
ALIGNMENT
HEADLAMP UNIT ALIGNMENT PREPARATION
(1) Verify headlamp dimmer switch and high beam
indicator operation.
(2) Inspect and correct damaged or defective com-
ponents that could interfere with proper headlamp
alignment.
(3) Verify proper tire inflation.
(4) Clean headlamp lenses.
(5) Verify that luggage area is loaded as the vehi-
cle is routinely used.
(6) Vehicles equipped with automatic load leveling
suspension should be driven normally for approxi-
mately 5 km (3 miles) before attempting a proper
headlamp unit alignment.
(7) Fuel tank should be FULL. Add 2.94 kg (6.5
lbs.) of weight over the fuel tank for each estimated
gallon of missing fuel.
ALIGNMENT SCREEN PREPARATION
(1) Position vehicle on a level surface perpendicu-
lar to a flat wall 7.62 meters (25 ft.) away from front
of headlamp lens (Fig. 13).
(2) If necessary, tape a line on the floor 7.62
meters (25 ft.) away from and parallel to the wall.
(3) Rock vehicle side-to-side three times and allow
suspension to stabilize.
(4) Jounce front suspension three times by pushing
downward on front bumper and releasing.
Fig. 12 HEADLAMP SWITCH CONNECTOR
RSLAMPS/LIGHTING - EXTERIOR8L-13
HEADLAMP SWITCH (Continued)
Page 550 of 2585

(3) Verify proper tire inflation.
(4) Clean headlamp lenses.
(5) Verify that luggage area is loaded as the vehi-
cle is routinely used.
(6) Vehicles equipped with automatic load leveling
suspension should be driven normally for approxi-
mately 5 km (3 miles) before attempting a proper
headlamp unit alignment.
(7) Fuel tank should be FULL. Add 2.94 kg (6.5
lbs.) of weight over the fuel tank for each estimated
gallon of missing fuel.
ALIGNMENT SCREEN PREPARATION
(1) Position vehicle on a level surface perpendicu-
lar to a flat wall 10 meters (32.8 ft.) away from front
of headlamp lens (Fig. 15).
(2) If necessary, tape a line on the floor 10 meters
(32.8 ft.) away from and parallel to the wall.
(3) Rock vehicle side-to-side three times and allow
suspension to stabilize.
(4) Jounce front suspension three times by pushing
downward on front bumper and releasing.
(5) Measure the distance from the center of head-
lamp lens to the floor. Transfer measurement to the
alignment screen (with tape). Use this line for
up/down adjustment reference.
HEADLAMP UNIT ADJUSTMENT
The low beam headlamp will project on the screen
upper edge of the beam (cut-off) at the horizontal
lamp cut-off line 20 mm (0.75 in.). The high beam
pattern should be correct when the low beams are
aligned properly (Fig. 15). To adjust headlamp align-
ment, rotate adjustment screws (Fig. 16) to achieve
the specified low beam cut-off location.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the three retaining screws (Fig. 17).
(3) Disconnect the wiring harness from the bulbs
(Fig. 18).
(4) Remove wire harness retainer from back of
headlamp unit.
(5) Remove the headlamp unit.
Fig. 14 HEADLAMP UNIT ADJUSTMENT
1 - ADJUSTMENT LOCATION
2 - HEADLAMP UNIT
RSLAMPS/LIGHTING - EXTERIOR8L-15
HEADLAMP UNIT (Continued)
Page 552 of 2585

INSTALLATION
(1) Reconnect wire harness to the bulbs.
(2) Install wire harness retainer to headlamp unit.
(3) Install the three retaining screws.
(4) Reconnect the battery negative cable.
HEADLAMP UNIT - EXPORT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the three retaining screws.
(3) Disconnect the central wiring harness connec-
tor from the headlamp unit.
(4) Remove the headlamp unit from vehicle.
INSTALLATION
(1) Connect the wiring harness to the headlamp
unit's central connector.
(2) Place headlamp unit into headlamp unit pocket
in front end.
(3) Install the three retaining screws.
(4) Connect the battery negative cable.
(5) Verify vehicle and system operation.
LICENSE LAMP
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove two screws (Fig. 19).
(3) Twist bulb socket and remove (Fig. 20).
(4) Pull bulb from socket.
INSTALLATION
(1) Push bulb into socket.
(2) Install socket into lamp.
(3) Install two screws.
(4) Reconnect the battery negative cable.
MULTI-FUNCTION SWITCH
DESCRIPTION - TURN SIGNAL SYSTEM
The turn signals are actuated with a lever on
Multi-Function Switch, located on the left side of the
steering wheel. The signals are automatically turned
off by a canceling cam (two lobes molded to the clock
spring mechanism). The cam comes in contact with
the cancel actuator on the turn signal (multi-func-
tion) switch assembly. Either cam lobe, pushing on
the cancel actuator, returns the switch to the OFF
position. The multi-function switch is a resistive
MUX switch that feeds inputs to the BCM.
Fig. 18 HEADLAMP UNIT
1 - HEADLAMP UNIT
2 - HEADLAMP
3 - PARK/TURN SIGNAL LAMP
4 - WIRE HARNESS RETAINER
Fig. 19 LICENSE PLATE LAMP UNITS
1 - SCREW
2 - LICENSE PLATE LAMP
Fig. 20 LICENSE PLATE LAMP - REMOVE/INSTALL
1 - LICENSE PLATE LAMP UNIT
2 - BULB
RSLAMPS/LIGHTING - EXTERIOR8L-17
HEADLAMP UNIT (Continued)
Page 553 of 2585

OPERATION - TURN SIGNAL SYSTEM
Lane change signaling is actuated by applying par-
tial turn signal stalk movement toward the direction
desired until the indicator lamps flashes in the
instrument cluster. When the switch stalk is released
the stalk will spring back into the neutral position
turning OFF the turn signal.
With the ignition switch ON and the turn signal
switch stalk actuated left or right, current flows
through the:
²Multi-function switch
²Body Control Module
²Integrated Power Module (IPM)
²Turn indicator lamp
²Front and rear turn signal bulbs.
A chime will sound after the vehicle has traveled a
distance of approximately 1.0 mile and a speed of 15
mph, with the turn signal ON.
DIAGNOSIS AND TESTING - MULTI-FUNCTION
SWITCH
To test turn signal, headlamp beam select and opti-
cal horn portion of the multi-function switch:
(1) Remove the multi-function switch, refer to
Electrical, Lamps/Lighting - Exterior, Multi-Function
Switch, Removal, and Installation.
(2) Using an ohmmeter check the resistance read-
ings between multi-function switch pins. Refer to
Wiring Diagrams for proper pin numbers and the
MULTI-FUNCTION SWITCH RESISTANCE table.
MULTI-FUNCTION SWITCH RESISTANCE
SWITCH
POSITIONPIN NUMBER RESISTANCE
LEFT 2 AND 3 2.7V 5%
RIGHT 2 AND 3 1KV 5%
OPTICAL
HORN2 AND 4 1.7KV 5%
HI BEAM 2 AND 4 2.32KV 5%
REMOVAL
(1) Disconnect and isolate battery negative cable.
(2) Remove upper and lower steering column
shrouds. Refer to Steering, Column, Shroud,
Removal.
(3) Disconnect wire connector from back of multi-
function switch.
(4) Remove screws holding multi-function switch to
steering column adapter collar.
(5) Remove the multi-function switch.
INSTALLATION
(1) Position the switch on to the steering column.
(2) Install the two retaining screws.(3) Connect the wire harness connector.
(4) Install the upper and lower steering column
shrouds. Refer to Steering, Column, Shroud, Installa-
tion.
(5) Connect the battery negative cable.
PARK/TURN SIGNAL LAMP
REMOVAL
(1) Disconnect and isolate battery negative cable.
(2) Remove headlamp retaining screws.
(3) Twist socket counter - clockwise and remove
(Fig. 21).
(4) Pull bulb from socket.
INSTALLATION
(1) Push bulb into socket.
(2) Twist socket into headlamp.
(3) Install headlamp retaining screws.
(4) Reconnect battery negative cable.
TAIL LAMP
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the tail lamp unit. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/TAIL
LAMP UNIT - REMOVAL).
(3) Squeeze the tabs on the bulb socket and
remove from tail lamp unit (Fig. 22).
(4) Pull bulb from lamp socket.
Fig. 21 PARK/TURN SIGNAL LAMP
1 - PARK/TURN SIGNAL LAMP
2 - LAMP SOCKET
8L - 18 LAMPS/LIGHTING - EXTERIORRS
MULTI-FUNCTION SWITCH (Continued)
Page 561 of 2585

also affect compass operation. If the vehicle roof
should become magnetized, the demagnetizing and
calibration procedures found in this section may be
required to restore proper compass operation.
DESCRIPTION - TEMPERATURE
All the available overhead consoles on this model
include Temperature information. The temperature
displays the outside ambient temperature in whole
degrees. The temperature display can be toggled
from Fahrenheit to Celsius by selecting the desired
U.S./Metric option from the customer programmable
features. The displayed temperature is not an instant
reading of conditions, but an average temperature. It
may take the temperature display several minutes to
respond to a major temperature change, such as driv-
ing 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 electronic control modules (CT, CMTC, EVIC)
memory. When the ignition switch is turned to the
On position again, the electronic module will display
the memory temperature for one minute; then update
the display to the current average temperature read-
ing within five minutes.
The temperature function is supported by an ambi-
ent temperature sensor. The sensor is mounted out-
side the passenger compartment near the front and
center of the vehicle, and is hard wired to the Front
Control Module (FCM). The FCM sends temperature
status messages to the module over the J1850 PCI
data bus circuit.
Following are general descriptions of the major
components used in the overhead console. Refer to
Wiring Diagrams for complete circuit schematics.
OPERATION
Refer to the vehicle Owner's Manual for specific
operation of each overhead console and its systems.
DIAGNOSIS AND TESTING - OVERHEAD
CONSOLE
If the problem with the overhead console is an
inaccurate or scrambled display, refer toSelf-Diag-
nostic Testbelow. If the problem with the overhead
console is incorrect Vacuum Fluorescent Display
(VFD) dimming levels, use a DRB IIItscan tool and
the proper Diagnostic Procedures manual to test for
the correct dimming message inputs being received
from the Body Control Module (BCM) or Front Con-
trol Module (FCM) over the J1850 Programmable
Communications Interface (PCI) data bus circuit. If
the problem is a no-display condition, use the follow-
ing procedures. For complete circuit diagrams, refer
toOverhead Consolein the Wiring Diagrams sec-
tion of the service manual.(1) Check the fused B(+) fuse in the integrated
power module. If OK, go to Step 2. If not OK, repair
the shorted circuit or component as required and
replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the integrated power module. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit to the
fused B(+) fuse in the integrated power module as
required.
(3) Check the fused ignition switch output (run/
start) fuse in the integrated power module. 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 integrated power mod-
ule. 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 cavity of the roof wire
harness connector for the electronics module 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 electronics mod-
ule. If OK, go to Step 7. If not OK, repair the open
fused B(+) circuit to the fused B(+) fuse in the inte-
grated power module 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 electronics module. If OK, refer
toSelf-Diagnostic Test
later this group for further
diagnosis of the electronics module and the J1850
PCI data bus circuit. If not OK, repair the open fused
ignition switch output (run/start) circuit to the fuse
in the integrated power module as required.
SELF-DIAGNOSTIC TEST
A self-diagnostic test is used to determine that the
electronics module is operating properly, and that all
the J1850 PCI data bus messages are being received
for initial operation. Initiate the self-diagnostic test
as follows:
(1) With the ignition switch in the Off position, on
Electronic Vehicle Information Center (EVIC) and
Compass Mini-Trip Computer (CMTC) equipped vehi-
cles simultaneously depress and hold theSTEP and
the RESET buttons. On Compass Temperature
Module (CT) equipped vehicles depress theC/T and
the US/M push buttons.
8M - 2 MESSAGE SYSTEMSRS
OVERHEAD CONSOLE (Continued)
Page 570 of 2585

Transmitter and the EVIC module are inoperative,
refer toElectronic Vehicle Information Center
Diagnosis and Testingin this group for further
diagnosis. For complete circuit diagrams, refer to
Wiring Diagrams. (Fig. 5) as described below:
(1) Turn the Radio Frequency (RF) Detector ON. A
ªchirpº will sound and the green power LED will
light. If the green LED does not light, replace the
battery.
(2) Hold the RF detector within one inch of the
TRAINED universal transmitter and press any of the
transmitters buttons.
(3) The red signal detection LEDs will light and
the tool will beep if a radio signal is detected. Repeat
this test three times.
STANDARD PROCEDURE
STANDARD PROCEDURE - SETTING
TRANSMITTER CODES
(1) Turn off the engine.
(2) Erase the codes by pressing the two outside
buttons. Release the buttons when the display con-
firms the operation (about 20 seconds).
(3) Choose one of the three buttons to train. Place
the hand-held transmitter within one inch of the uni-
versal transmitter and push the buttons on both
transmitters.(4) Release both buttons. Your universal transmit-
ter is now ªtrainedº. To train the other buttons,
repeat Step 3 and Step 4. Be sure to keep your hand-
held transmitter in case you need to retrain the uni-
versal transmitter.
STANDARD PROCEDURE - ERASING
TRANSMITTER CODES
To erase the universal transmitter codes, simply
hold down the two outside buttons until the display
confirms the operation.
NOTE: Individual channels cannot be erased. Eras-
ing the transmitter codes will erase ALL pro-
grammed codes.
REMOVAL
(1) For universal transmitter removal and installa-
tion procedure, (Refer to 8 - ELECTRICAL/OVER-
HEAD CONSOLE/COMPASS/MINI-TRIP
COMPUTER - REMOVAL and INSTALLATION).
AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the over-
head console through ambient temperature messages
received from the Front Control Module (FCM) over
the Programmable Communications Interface (PCI)
J1850 data bus circuit. The FCM receives a hard
wired input from the ambient temperature sensor.
The ambient temperature sensor is a variable resis-
tor mounted to a bracket that is secured with a screw
to the right side of the headlamp mounting module
grille opening, behind the radiator grille and in front
of the engine compartment.
For more information on the Front Control Module
refer to the Electronic Control Modules section of this
manual. For complete circuit diagrams, refer to the
appropriate wiring information. The ambient temper-
ature 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 Front Control Module. The resis-
tance in the sensor changes as temperature changes,
changing the temperature sensor signal circuit volt-
age to the Front Control Module. Based upon the
resistance in the sensor, the Front Control Module
senses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The Front Control Module
Fig. 5 RADIO FREQUENCY DETECTOR
1 - SIGNAL DETECTION LED'S
2 - POWER LED
3 - ON/OFF SWITCH
4 - 9V BATTERY
RSMESSAGE SYSTEMS8M-11
UNIVERSAL TRANSMITTER (Continued)
Page 571 of 2585

then sends the proper ambient temperature mes-
sages to the EVIC, CMTC over the PCI J1850 data
bus.
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, the
Front Control Module, the Programmable Communi-
cations Interface (PCI) data bus, and a portion of the
Electronics module. If any portion of the ambient
temperature sensor circuit fails, the Front Control
Module will self-diagnose the circuit.
The ambient temperature sensor circuit can also be
diagnosed by referring toDiagnosis and Testing -
Ambient Temperature Sensor, and Diagnosis
and Testing - Ambient Temperature Sensor Cir-
cuit. If the temperature sensor and circuit are con-
firmed to be OK, but the temperature display is
inoperative or incorrect, refer toDiagnosis and
Testing - Overhead Consolein this group. For
complete circuit diagrams, refer to the appropriate
wiring information.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(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 336.6 kilohms. At 60É C (140É F), the sensor
resistance is 2.49 kilohms. The sensor resistance
should read between these two values. If OK, refer to
Diagnosis and Testing - Ambient Temperature
Sensor Circuitin this group. If not OK, replace the
faulty ambient temperature sensor.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(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 Front Control Module wire
harness 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 Front Control Module wire har-
ness 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 Front Control Module
wire harness 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 Front
Control Module wire harness connector and a good
ground. There should be no continuity. If OK, refer to
Diagnosis and Testing - Overhead Consolein
this group. If not OK, repair the shorted ambient
temperature sensor signal circuit as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) From behind front bumper fascia, remove
screw holding sensor to radiator closure panel.
(3) Disconnect the sensor electrical connector.
Depress the connector retaining tab and pull the con-
nector straight off the ambient temperature sensor.
(4) Remove sensor from vehicle.
INSTALLATION
(1) Position the sensor in the vehicle and connect
the sensor electrical connector.
(2) From behind the front bumper fascia, install
the screw holding sensor to radiator closure panel.
(3) Connect the battery negative cable.
8M - 12 MESSAGE SYSTEMSRS
AMBIENT TEMP SENSOR (Continued)