SPEEDOMETER DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO POINTER
MOVEMENT1. INTERNAL CLUSTER
FAILURE.1.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF SPEEDOMETER POINTER MOVES TO
CALIBRATION POINTS DURING TEST LOOK FOR
ANOTHER POSSIBLE CAUSE OF FAILURE.
²IF THE POINTER DOESN'T MOVE DURING TEST,
CHECK FOR POWER AND GROUND TO THE MIC.
IF POWER AND GROUND ARE PRESENT GO TO
STEP 1.B.
1.B. REPLACE CLUSTER. GO TO STEP 1.C.
1.C. CONNECT CLUSTER INTO INSTRUMENT
PANEL WIRING HARNESS. PLACE IT BACK INTO
THE PROPER POSITION IN THE INSTRUMENT
PANEL. PUT IN THE TOP FOUR MOUNTING
SCREWS AND SECURE THE CLUSTER TO THE
INSTRUMENT PANEL.
2. NO SPEED PCI BUS
MESSAGE OR ZERO
MPH PCI SPEED BUS
MESSAGE.2.A. CHECK THE PCM (CODE 10) USING A DRB IIIT
SCAN TOOL. IF OK, GO TO STEP 2.B. IF NOT OK,
REFER TO THE PROPER ENGINE DIAGNOSTIC
PROCEDURES MANUAL TO REPAIR THE PCM.
2.B. CHECK THE SPEED SIGNAL INPUT INTO THE
PCM. THE SPEED SIGNAL ORIGINATES FROM ONE
OF THE FOLLOWING SOURCES:
²A DISTANCE SENSOR FOR VEHICLES WITH 3
SPEED AUTOMATIC TRANSMISSION. CHECK
CONTINUITY FROM DISTANCE SENSOR TO PCM.
IF OK, REPLACE DISTANCE SENSOR. IF NOT OK,
REPAIR WIRING.
²THE TCM FOR VEHICLES WITH THE 4 SPEED
ELECTRONIC TRANSMISSIONS. CHECK
CONTINUITY FROM TCM TO PCM. IF OK, USE A
DRB IIITSCAN TOOL TO CHECK TCM. REFER TO
THE PROPER TRANSMISSION DIAGNOSTIC
PROCEDURES MANUAL TO REPAIR THE TCM. IF
NOT OK, REPAIR WIRING.
8J - 4 INSTRUMENT CLUSTERRS
INSTRUMENT CLUSTER (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
ERRATIC POINTER
MOVEMENT1. ERRATIC MESSAGE
FROM ANOTHER
MODULE.1.A. CHECK THE BCM USING A DRB IIITSCAN
TOOL IF OK, GO TO STEP 1.B. IF NOT OK, REFER
TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO REPAIR THE BCM.
1.B. CHECK THE PCM USING A DRB IIITSCAN
TOOL. IF OK, GO TO STEP 1.C. IF NOT OK, REFER
TO THE ENGINE DIAGNOSTIC PROCEDURES
MANUAL TO REPAIR THE PCM.
1.C. CHECK THE SPEED SIGNAL INPUT INTO THE
PCM. THE SPEED SIGNAL ORIGINATES FROM ONE
OF THE FOLLOWING SOURCES:
²A DISTANCE SENSOR FOR VEHICLES WITH 3
SPEED AUTOMATIC TRANSMISSION. CHECK
CONTINUITY FROM DISTANCE SENSOR TO PCM.
IF OK, REPLACE DISTANCE SENSOR. IF NOT OK,
REPAIR WIRING.
²THE TCM FOR VEHICLES WITH THE 4 SPEED
ELECTRONIC TRANSMISSIONS. CHECK
CONTINUITY FROM TCM TO ENGINE
CONTROLLER. IF OK, USE A DRB IIITSCAN TOOL
TO CHECK TCM. REFER TO THE PROPER
TRANSMISSION DIAGNOSTIC PROCEDURES
MANUAL TO REPAIR THE TCM. IF NOT OK, REPAIR
WIRING.
2. INTERNAL CLUSTER
FAILURE.2.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT
STILL APPEARS ERRATIC, THEN GO TO STEP 2.B.
2.B. REPLACE CLUSTER ASSEMBLY.
RSINSTRUMENT CLUSTER8J-5
INSTRUMENT CLUSTER (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
SPEEDOMETER
INACCURATE.1. SPEEDOMETER OUT
OF CALIBRATION.1.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
²IF SPEEDOMETER IS ACCURATE TO THE
CALIBRATION POINTS THEN LOOK FOR ANOTHER
POSSIBLE CAUSE OF INACCURACY.
²IF SPEEDOMETER IS NOT ACCURATE TO THE
CALIBRATION POINTS, REPLACE CLUSTER
ASSEMBLY.
2. WRONG
SPEEDOMETER PINION
SIZE FOR TIRE SIZE.2.A. IF VEHICLE HAS A 4 SPEED ELECTRONIC
TRANSMISSION GO TO STEP 2.C. OTHERWISE GO
TO STEP 2.B.
2.B. CHECK IF CORRECT SPEEDOMETER PINION
IS BEING USED WITH TIRES ON VEHICLE. REFER
TO TRANSMISSION FOR DIAGNOSIS AND
TESTING.
²IF THE INCORRECT PINION IS IN TRANSMISSION
THEN REPLACE WITH CORRECT PINION.
²IF THE CORRECT PINION IS IN THE
TRANSMISSION, CHECK TIRE SIZE.
2.C. USE A DRB IIITSCAN TOOL TO CHECK THE
TCM TO SEE IF THE CORRECT TIRE SIZE HAS
BEEN PROGRAMMED INTO THE TCM.
²IF THE INCORRECT TIRE SIZE WAS SELECTED,
SELECT THE PROPER TIRE SIZE.
²IF THE CORRECT TIRE SIZE WAS SELECTED,
CHECK SPEED SENSOR.
3. BAD SPEED SENSOR. 3. REFER TO TRANSMISSION, SPEED SENSOR,
DIAGNOSIS AND TESTING.
TACHOMETER DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO POINTER
MOVEMENT1. INTERNAL
CLUSTER FAILURE.1.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST AND
CHECK FOR FAULT CODES.
²IF TACHOMETER POINTER MOVES TO CALIBRATION
POINTS DURING TEST, LOOK FOR ANOTHER
POSSIBLE CAUSE OF FAILURE.
²
IF THE POINTER DOESN'T MOVE DURING TEST,
CHECK FOR POWER AND GROUND TO THE MIC.
IF POWER AND GROUND ARE PRESENT GO TO
STEP 1.B.
1.B. REPLACE CLUSTER. GO TO STEP 1.C.
2.9NO RPM9PCI BUS
MESSAGE OR9ZERO
RPM9PCI BUS
MESSAGE FROM
PCM.2. CHECK THE PCM USING A DRB IIITSCAN TOOL.
REFER TO THE PROPER ENGINE DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE AND
REPAIR.
8J - 6 INSTRUMENT CLUSTERRS
INSTRUMENT CLUSTER (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
ERRATIC POINTER
MOVEMENT.1. BAD PCI BUS
MESSAGE FROM
PCM.1. CHECK THE PCM USING A DRB IIITSCAN TOOL.
REFER TO THE PROPER ENGINE DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE AND
REPAIR.
2. INTERNAL
CLUSTER FAILURE.2.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST AND
CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT STILL
APPEARS ERRATIC, REPLACE CLUSTER ASSEMBLY.
TACHOMETER
INACCURATE.1. TACHOMETER OUT
OF CALIBRATION.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
²IF TACHOMETER IS ACCURATE TO THE CALIBRATION
POINTS, LOOK FOR ANOTHER POSSIBLE CAUSE OF
INACCURACY.
²IF TACHOMETER IS NOT ACCURATE TO THE
CALIBRATION POINTS, REPLACE CLUSTER ASSEMBLY.
FUEL GAUGE DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO POINTER
MOVEMENT.1. INTERNAL CLUSTER
FAILURE.1.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
²IF FUEL GAUGE POINTER MOVES TO
CALIBRATION POINTS, LOOK FOR ANOTHER
POSSIBLE CAUSE OF FAILURE.
²IF THE POINTER DOESN'T MOVE DURING TEST,
VERIFY POWER AND GROUND ARE BEING
PROVIDED TO THE CLUSTER. IF YES, REPLACE
CLUSTER ASSEMBLY. IF NO, DETERMINE CAUSE
OF NO POWER OR GROUND.
2. NO PCI FUEL
MESSAGE OR EMPTY
PCI BUS MESSAGE
FROM BODY
CONTROLLER.2.A. CHECK THE BCM USING A DRB IIITSCAN
TOOL. IF OK, GO TO STEP 2.B. IF NOT OK, REFER
TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
2.B. REFER TO THE FUEL SECTION OF THE
SERVICE MANUAL FOR THE FUEL LEVEL SENDING
UNIT TEST PROCEDURE. TEST UNIT AND REPAIR
AS INSTRUCTED.
ERRATIC POINTER
MOVEMENT.1. BAD PCI FUEL
MESSAGE FROM THE
BODY CONTROLLER.1.A. USE A DRB IIITSCAN TOOL TO CHECK THE
BCM. IF OK, GO TO STEP 2.B. IF NOT OK, REFER
TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
2.B. REFER TO THE FUEL SECTION OF THE
SERVICE MANUAL FOR THE FUEL LEVEL SENDING
UNIT TEST PROCEDURE. TEST UNIT. IF OK, LOOK
FOR ANOTHER POSSIBLE CAUSE FOR FUEL
GAUGE FAILURE. IF NOT OK, REPAIR SENDING
UNIT.
RSINSTRUMENT CLUSTER8J-7
INSTRUMENT CLUSTER (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
2. INTERNAL CLUSTER
FAILURE.2. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT
STILL APPEARS ERRATIC, REPLACE CLUSTER
ASSEMBLY.
FUEL GAUGE
INACCURATE.1. FUEL GAUGE OUT OF
CALIBRATION.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST. IF
POINTER IS ACCURATE TO THE CALIBRATION
POINTS LOOK FOR ANOTHER POSSIBLE CAUSE
OF FAILURE. IF POINTER IS INACCURATE TO THE
CALIBRATION POINTS, REPLACE CLUSTER
ASSEMBLY.
2. FUEL LEVEL SENDING
UNIT IS OUT OF
CALIBRATION.2. REFER TO THE FUEL SECTION OF THE SERVICE
MANUAL FOR TESTING AND REPAIR PROCEDURE.
TEMPERATURE GAUGE DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO POINTER
MOVEMENT1. INTERNAL CLUSTER
FAILURE.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK.
²IF TEMPERATURE GAUGE POINTER MOVES TO
CALIBRATION POINTS, LOOK FOR ANOTHER
POSSIBLE CAUSE OF FAILURE.
²IF THE POINTER DOESN'T MOVE DURING TEST,
VERIFY POWER AND GROUND ARE BEING
PROVIDED TO THE CLUSTER. IF YES, REPLACE
CLUSTER. IF NO, DETERMINE CAUSE OF NO
POWER OR NO GROUND.
2. NO PCI
TEMPERATURE
MESSAGE OR COLD PCI
BUS MESSAGE FROM
THE POWERTRAIN
CONTROL MODULE.2.A. CHECK PCM FAULT CODES USING A DRB IIIT
SCAN TOOL. IF THERE ARE NO FAULTS, GO TO
STEP 2.B. IF THERE ARE FAULTS, REFER TO THE
PROPER ENGINE DIAGNOSTIC PROCEDURES
MANUAL TO PROPERLY DIAGNOSE AND REPAIR.
2.B. REFER TO FUEL, COOLANT TEMPERATURE
SENSOR, DIAGNOSIS AND TESTING. REPAIR
SENSOR AS NEEDED.
ERRATIC POINTER
MOVEMENT.1. BAD PCI BUS
MESSAGE FROM THE
POWERTRAIN CONTROL
MODULE.1.A. CHECK PCM FAULT CODES USING A DRB IIIT
SCAN TOOL. IF THERE ARE NO FAULTS, GO TO
STEP 1.B. IF THERE ARE FAULTS, REFER TO THE
ENGINE DIAGNOSTIC PROCEDURES MANUAL TO
PROPERLY DIAGNOSE AND REPAIR.
1.B. REFER TO FUEL, COOLANT TEMPERATURE
SENSOR, DIAGNOSIS AND TESTING. REPAIR
SENSOR AS NEEDED.
2. INTERNAL CLUSTER
FAILURE.2. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT
STILL APPEARS ERRATIC, REPLACE CLUSTER
ASSEMBLY.
8J - 8 INSTRUMENT CLUSTERRS
INSTRUMENT CLUSTER (Continued)
DAYTIME RUNNING LAMPS
Power is reduced using pulse-width modulation to
the high beams, where by the power is switched on
and off rapidly instead of remaining on continuously.
The duration and interval of the power pulses is pro-
grammed into the Front Control Module (FCM).
HEADLAMP SYSTEM
The headlamp system will default to headlamps
ON position when ignition switch is ON and when an
open or short circuit failure occurs on the headlamp
switch input. The system will return to normal oper-
ation when the open or short is repaired. A fault will
be reported by the BCM when a failure occurs on the
dimmer or headlamp switch input.
If the exterior lamps are ON and the headlamp
switch is in any position other than OFF or AUTO
and with the ignition switch OFF (LOCK) after 3
minutes the BCM sends a message via J1850 to the
FCM informing the FCM to turn off the headlamps,
park lamps and fog lamps. This feature prevents the
vehicle battery from being discharged when the vehi-
cle lights have been left ON.
HEADLAMP TIME DELAY SYSTEM
The headlamp time delay system is activated by
turning the headlamps ON (high or low beam) while
the engine is running, turning the ignition switch
OFF, and then turning the headlamp switch OFF
within 45 seconds. The system will not activate if
more than 45 seconds elapse between ignition switch
OFF and headlamp switch OFF. The BCM will allow
the headlamps to remain ON for 90 seconds (config-
urable) before they automatically turn off (If the key
is in the ignition during the headlamp time delay
mode, then both the headlamps and park lamps
(including panel dimming) will be ON). Refer to the
Owner's Manual for more information.
If the headlamp switch is in the Auto Headlamp
Position, the headlamps are ON due to the night sig-
nal from the CMTC and the ignition switch is in any
position other than run/start, the BCM shall enter a
90 second (configurable) Auto Headlamps time delay
mode. If the key is in the ignition during the head-
lamp time delay mode, then both the headlamps and
park lamps (including panel dimming) will be ON. If
the key is not in the ignition, then only the head-
lamps will be ON. The BCM will allow the head-
lamps to remain ON for 90 seconds before they
automatically turn OFF. Refer to the Owner's Man-
ual for more information.
LAMP OUTAGE
If one or more of the following lamps (Low and/or
High beams) are out, then a ªlamps outº indicator
located in the cluster will illuminate.
OPTICAL HORN/HIGH BEAMS
When the multifunction switch is pulled to the first
detent (optical horn) signal, the headlamps are ON,
key-in the ignition the BCM shall send a message via
J1850 to the FCM to turn on the headlamps drivers
to illuminate all four filaments (Low and High
beams). When the multifunction switch is pulled to
the second detent (high beam) signal and the head-
lamps are ON, the BCM shall send a message via
J1850 to the FCM to turn on the headlamps drivers.
The High Beams are illuminated and the Low Beams
and Fog Lamps (if ON) are extinguished. If the head-
lamps were in the high beam configuration when
power was removed from the headlamps, the head-
lamps will be configured as low beam the next time
they are activated.
DIAGNOSIS AND TESTING
WARNING: EYE PROTECTION SHOULD BE USED
WHEN SERVICING GLASS COMPONENTS. PER-
SONAL INJURY CAN RESULT.
CAUTION: Do not touch the glass of halogen bulbs
with fingers or other possibly oily surface, reduced
bulb life will result. Do not use bulbs other than
those indicated in the Bulb Application table. Dam-
age to lamp and/or Daytime Running Lamp Module
can result. Do not use fuses, circuit breakers or
relays having greater amperage value than indi-
cated on the fuse panel or in the Owners Manual.
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. 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 connec-
tors, splices and grounds.
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.
RSLAMPS/LIGHTING - EXTERIOR8L-3
LAMPS/LIGHTING - EXTERIOR (Continued)
DIAGNOSIS & TESTING - HOMELINKT
If the Homelinktis inoperative, but the Electronic
Vehicle Information Center (EVIC) or Compass Mini-
Trip Computer is operating normally, see the owner's
manual in the vehicle glove box for instructions on
training the Homelinkt. Retrain the Homelinktwith
a known good transmitter as instructed in the own-
er's manual and test the Homelinktoperation again.
If the unit is still inoperative, replace the faulty
Homelinktand EVIC/CMTC module as a unit. If
both the Homelinktand the EVIC/CMTC module are
inoperative, refer toOverhead Console Diagnosis
and Testingearlier in this group for further diagno-
sis. For complete circuit diagrams, refer toOver-
head Consolein Wiring Diagrams.
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.
Refer toFront Control Modulein Electronic
Control Modules. For complete circuit diagrams, refer
to the appropriate wiring information. 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 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
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 ambienttemperature 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 - 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 kilohms. At 55É C (140É F), the sensor
resistance is 2.488 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
RSOVERHEAD CONSOLE8M-11
UNIVERSAL TRANSMITTER (Continued)
the OFF position. Replace the first valid Sentry Key
in the ignition lock cylinder with the second valid
Sentry Key and turn the ignition switch back to the
ON position. The second valid Sentry Key must be
inserted within 15 seconds of removing the first valid
Sentry key.
(4) About ten seconds after the completion of Step
3, the indicator light will start to flash and a single
audible chime tone will sound to indicate that the
system has entered the9Customer Learn9program-
ming mode.
(5) Within sixty seconds of entering the9Customer
Learn9programming mode, turn the ignition switch
to the OFF position, replace the valid Sentry Key
with a blank Sentry Key transponder, and turn the
ignition switch back to the ON position.
(6) About ten seconds after the completion of Step
5, a single audible chime tone will sound and the
indicator light will stop flashing and stay on solid for
three seconds and then turn off to indicate that the
blank Sentry Key has been successfully programmed.
The SKIS will immediately exit the9Customer
Learn9programming mode and the vehicle may be
started using the newly programmed Sentry Key.
These steps must be completed in their entirety for
each additional Sentry Key to be programmed. If any
of the above steps are not completed in the given
sequence, or within the allotted time, the SKIS will
exit the9Customer Learn9programming mode and
the programming will be unsuccessful. The SKIS will
also automatically exit the9Customer Learn9pro-
gramming mode if:
²It sees a non-blank Sentry Key when it should
see a blank.
²If it has already programmed eight (8) valid
Sentry Keys.
²If the ignition switch is turned to the OFF posi-
tion for more than about fifty (50) seconds.
NOTE: If you attempt to start the vehicle while in
ªCustomer Learnº mode (LED flashing), the vehicle
will behave as though an invalid key is being used
(i.e. the engine will stall after two (2) seconds of
running). No faults will be logged.
NOTE: Once a Sentry Key has been programmed to
a particular vehicle, it cannot be used on any other
vehicle.VTSS/SKIS INDICATOR LAMP
DESCRIPTION
The Sentry Key Immobilizer System (SKIS) uses
an indicator light to convey information on the status
of the system to the customer. This light is shared
with the Vehicle Theft Security System (VTSS). The
light is located in the Message Center. The indicator
light is controlled by the Body Control Module (BCM)
based upon messages it receives from the Sentry Key
Immobilizer Module (SKIM) on the PCI bus.
OPERATION
The BCM performs a four second bulb check,
regardless of SKIM messages. After the bulb check,
the lamp is controlled according to SKIM messages.
Then, the SKIM sends messages to the BCM to oper-
ate the light based upon the results of the SKIS self
tests. The light may be actuated in two possible
ways, flashing or on solid. If the light comes on and
stays on solid after a power-up test, this indicates
that the SKIM has detected a system malfunction. If
the SKIM detects an invalid key when the ignition
switch is moved to the ON position, it sends a mes-
sage on the PCI bus to the BCM, to flash the light.
The SKIM can also send a message to flash the light
and generate a single audible chime at the same
time. These two events occurring simultaneously
indicate that the SKIS has been placed into the9Cus-
tomer Learn9mode. Refer to Electrical, Vehicle Theft
Security, Transponder Key, Standard Procedure -
Transponder Programming for more information on
the9Customer Learn9mode. If the light comes on
and stays on after the power-up test, diagnosis of the
SKIS should be performed using a DRB IIItscan tool
and the appropriate Body Diagnostic Procedures
manual. The light is not a serviceable component.
RSVEHICLE THEFT SECURITY8Q-5
TRANSPONDER KEY (Continued)