Refer to the appropriate Powertrain Diagnostic Man-
ual and the DRBIIItscan tool.
(1) Install PCM module to the mounting bracket.
(2) Install electrical connectors and lock.
(3) Install the splash shield.
(4) Lower vehicle.
(5) Connect the negative battery cable.
(6) Using DRBIIItscan tool, program mileage and
vehicle identification number (VIN) into PCM. Refer
to the DRBIIItscan tool and the appropriate Power-
train Diagnostic Manual.
SENTRY KEY IMMOBILIZER
MODULE
DESCRIPTION
The Sentry Key Immobilizer Module (SKIM) con-
tains a Radio Frequency (RF) transceiver and a
microprocessor. The SKIM retains in memory the ID
numbers of any Sentry Key that is programmed to it.
The maximum number of keys that may be pro-
grammed to each module is eight (8). The SKIM also
communicates over the Programmable Communica-
tion Interface (PCI) data bus with the Powertrain
Control Module (PCM), the Body Control Module
(BCM), the Mechanical Instrument Cluster (MIC),
and the DRB IIItscan tool. The SKIM transmits and
receives RF signals through a tuned antenna
enclosed within a molded plastic ring formation that
is integral to the SKIM housing. When the SKIM is
properly installed on the steering column, the
antenna ring fits snugly around the circumference of
the ignition lock cylinder housing. If this ring is not
mounted properly, communication problems may
arise in the form of transponder-related faults.
For added system security, each SKIM is pro-
grammed with a unique9Secret Key9code. This code
is stored in memory and is sent over the PCI bus to
the PCM and to each key that is programmed to
work with the vehicle. The9Secret Key9code is there-
fore a common element found in all components of
the Sentry Key Immobilizer System (SKIS). In the
event that a SKIM replacement is required, the
9Secret Key9code can be restored from the PCM by
following the SKIM replacement procedure found in
the DRB IIItscan tool. Proper completion of this
task will allow the existing ignition keys to be repro-
grammed. Therefore, new keys will NOT be needed.
In the event that the original9Secret Key9code can
not be recovered, new ignition keys will be required.
The DRB IIItscan tool will alert the technician if
key replacement is necessary. Another security code,
called a PIN, is used to gain secured access to the
SKIM for service. The SKIM also stores in its mem-
ory the Vehicle Identification Number (VIN), which itlearns through a bus message from the assembly
plant tester. The SKIS scrambles the information
that is communicated between its components in
order to reduce the possibility of unauthorized SKIM
access and/or disabling.
OPERATION
When the ignition switch is moved to the RUN
position, the Sentry Key Immobilizer Module (SKIM)
transmits an Radio Frequency (RF) signal to the
transponder in the ignition key. The SKIM then
waits for a response RF signal from the transponder
in the key. If the response received identifies the key
as valid, the SKIM sends a9valid key9message to
the Powertrain Control Module (PCM) over the Pro-
grammable Communication Interface (PCI) data bus.
If the response received identifies the key as invalid
or no response is received from the transponder in
the ignition key, the SKIM sends an9invalid key9
message to the PCM. The PCM will enable or disable
engine operation based upon the status of the SKIM
messages. It is important to note that the default
condition in the PCM is9invalid key.9Therefore, if no
response is received by the PCM, the engine will be
immobilized after two (2) seconds of running.
The SKIM also sends indicator light status mes-
sages to the Mechanical Instrument Cluster (MIC) to
operate the light. This is the method used to turn the
light ON solid or to flash it after the indicator light
test is complete to signify a fault in the SKIS. If the
light comes ON and stays ON solid after the indica-
tor light test, this signifies that the SKIM has
detected a system malfunction and/or that the SKIS
has become inoperative. If the SKIM detects an
invalid keyORa key-related fault exists, the indica-
tor light will flash following the indicator light test.
The SKIM may also request an audible chime if the
customer key programming feature is available and
the procedure is being utilized (Refer to 8 - ELEC-
TRICAL/VEHICLE THEFT SECURITY/TRANSPON-
DER KEY - STANDARD PROCEDURE).
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove Lower Instrument Panel Cover. Refer
to Body, Instrument Panel, Lower Instrument Panel
Cover, Removal.
(3) Remove the steering column upper and lower
shrouds. Refer to Steering, Column, Column Shroud,
Removal.
(4) Disengage the steering column wire harness
from the Sentry Key Immobilizer Module (SKIM).
(5) Remove the one screws securing the SKIM to
the steering column.
8E - 18 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)
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)
(2) Turn the ignition key to the ON position. Exit
vehicle with the scan tool.
(3) After checking that no one is inside the vehicle,
connect the battery negative remote terminal.
(4) Read and record theACTIVEDiagnostic Trou-
ble Code (DTC) data.
(5) Read and record anySTOREDDTC's.
(6) Refer to the proper Body Diagnostic Procedures
manual if any DTC's are found in Step 4 and Step 5.
(7) If the airbag warning lamp either fails to light,
or goes ON and stays ON, there is a system malfunc-
tion. To test the airbag warning lamp (bulb) opera-
tion in the cluster, refer to Electrical, Instrument
Cluster, Diagnosis and Testing - Instrument Cluster.
Refer to the proper Body Diagnostic Procedures man-
ual for any other system problems.
STANDARD PROCEDURE
STANDARD PROCEDURE - HANDLING
AIRBAGS
DEPLOYED AIRBAG
The vehicle interior may contain a very small
amount of sodium hydroxide powder, a by-product of
airbag deployment. Sodium hydroxide powder can
irritate the skin, eyes, nose and throat. Wear safety
glasses, rubber gloves, and long sleeved clothing
when cleaning any of the powder residue from the
vehicle.
If you find that the cleanup is irritating your skin,
run cool water over the affected area. Also, if you
experience nasal or throat irritation, exit the vehicle
for fresh air until the irritation ceases. If irritation
continues, see a physician.
UNDEPLOYED AIRBAG
The airbags must be stored in its original special
container until used for service. At no time should a
source of electricity be permitted near the inflator on
the back of an airbag module. When carrying or han-
dling an undeployed airbag module, the trim side of
the airbag should be pointing away from the body to
minimize possibility of injury if accidental deploy-
ment occurs. Do not place undeployed airbag face
down on a solid surface, the airbag will propel into
the air if accidental deployment occurs.
STANDARD PROCEDURE - SERVICE AFTER AN
AIRBAG DEPLOYMENT
DRIVER AIRBAG
After a Driver Airbag has been deployed due to a
collision, the followingMUSTbe replaced:
²Driver Airbag²Clock Spring Assembly
²Steering Wheel
²Complete Steering Column Assembly w/Lower
Steering Column Coupler
All other airbag and vehicle components should be
closely inspected following any airbag deployment,
and should be replaced when visible damage is
incurred.
PASSENGER AIRBAG
After a Passenger Airbag has been deployed due to
a collision. the followingMUSTbe replaced:
²Passenger Airbag
²Instrument Panel and Pad Assembly
All other airbag and vehicle components should be
closely inspected following any airbag deployment,
and should be replaced when visible damage is
incurred.
SEAT AIRBAG
After a Seat Airbag has been deployed due to a col-
lision. the followingMUSTbe replaced:
²Complete Seat Back Assembly
All other airbag and vehicle components should be
closely inspected following any airbag deployment,
and should be replaced when visible damage is
incurred.
SEAT BELTS AND TENSIONERS
After a frontal impact where an airbag has been
deployed due to a collision. the followingMUSTbe
replaced:
²Front Seat Belt Buckle (driver and passenger)
with integral Tensioners.
All other seat belts should be closely inspected for
cuts, tears, fraying, or damage in any way following
any frontal impact or airbag deployment. The other
seat belts are to be replaced when visible damage is
incurred. Inspect the Lower Anchors and Tether for
CHildren (LATCH) child restraint anchors for dam-
age after an impact event and replace as needed.
CLEAN UP PROCEDURE
Roll or fold the airbag towards its mounting point
(i.e. instrument panel, steering wheel, or seat back).
Then tape the ripped cover over the deployed airbag
if applicable.
Use a vacuum cleaner to remove any residual pow-
der from the vehicle interior. Work from the outside
in to avoid kneeling or sitting in a contaminated
area. Vacuum the heater and A/C outlets as well (Fig.
1). If the heater or air conditioner was in RECIRC
mode at time of airbag deployment, operate blower
motor on low speed and vacuum powder residue
expelled from the heater and A/C outlets. Multiple
RSRESTRAINTS8O-3
RESTRAINTS (Continued)
sends a9valid key9message to the Powertrain Con-
trol Module (PCM) over the Programmable Commu-
nication Interface (PCI) data bus. If the response
received identifies the key as invalid or no response
is received from the transponder in the ignition key,
the SKREEM sends an9invalid key9message to the
PCM. The PCM will enable or disable engine opera-
tion based upon the status of the SKREEM mes-
sages. It is important to note that the default
condition in the PCM is9invalid key.9Therefore, if no
response is received by the PCM, the engine will be
immobilized after two (2) seconds of running.
The SKREEM also sends indicator light status
messages to the Mechanical Instrument Cluster
(MIC) to operate the light. This is the method used to
turn the light ON solid or to flash it after the indi-
cator light test is complete to signify a fault in the
SKREES. If the light comes ON and stays ON solid
after the indicator light test, this signifies that the
SKREEM has detected a system malfunction and/or
that the SKREES has become inoperative. If the
SKREEM detects an invalid keyORa key-related
fault exists, the indicator light will flash following
the indicator light test. The SKREEM may also
request an audible chime if the customer key pro-
gramming feature is available and the procedure is
being utilized (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY/TRANSPONDER KEY - STAN-
DARD PROCEDURE).
REMOTE KEYLESS ENTRY (RKE)
After pressing the lock button on the RKE trans-
mitter, all of the door locks will lock, the illuminated
entry will turn off (providing all doors are closed),
and the VTSS (if equipped) will arm. After pressing
the unlock button, on the RKE transmitter, one time,
the driver door lock will unlock, the illuminated
entry will turn on the courtesy lamps, and the VTSS
(if equipped) will disarm. After pressing the unlock
button a second time, the remaining door locks will
unlock. The Electronic Vehicle Information Center
(EVIC) or the DRBIIItscan tool can reprogram this
feature to unlock all of the door locks with one press
of the unlock button. If the vehicle is equipped with
the memory system, the memory message will iden-
tify which transmitter (1 or 2) sent the signal.
The SKREEM is capable of retaining up to 8 indi-
vidual access codes (8 transmitters). If the PRNDL is
in any position except park, the SKREEM will dis-
able the RKE. The 4 button transmitter uses
1-CR2032 battery. The minimum battery life is
approximately 4.7 years based on 20 transmissions a
day at 84ÉF (25ÉC). Use the DRBIIItscan tool or the
Miller Tool 9001 RF Detector to test the RKE trans-
mitter. Use the DRBIIItor the customer program-
ming method to program the RKE system. However,the SKREEM will only allow RKE programming
when the ignition is in the ON position, the PRNDL
is in park position, and the VTSS (if equipped) is dis-
armed.
TIRE PRESSURE MONITORING (TPM)
The SKREEM monitors the signals from the tire
pressure sensor/transmitters and determines if any
tire has gone below the low pressure threshold LOW
TIRE PRESSURE THRESHOLDS table.
LOW TIRE PRESSURE THRESHOLDS
SYSTEM STATUS
INDICATORTIRE PRESSURE
ON 193 kPa (28 PSI)
OFF 227 kPa (33 PSI)
CRITICAL AND NON-CRITICAL SYSTEM ALERTS
CRITICAL:A critical alert will be triggered when
a tire pressure has gone below a set threshold pres-
sure. The SKREEM will display ªX TIRE(S) LOW
PRESSUREº. ªXº will be the number of tires report-
ing low pressure. The message will display for the
duration of the current ignition cycle or until an
EVIC button is pressed. If the display is removed
without correcting the condition, it will reappear 300
seconds to warn the driver of the low pressure condi-
tion.
NON-CRITICAL:A non-critical alert will be trig-
gered when no signal is received from a sensor/trans-
mitter. The EVIC display in the cluster will display
ªSERVICE TIRE SYSTEM SOON.º
DIAGNOSIS AND TESTING - SENTRY KEY
REMOTE ENTRY MODULE
For proper diagnosis and testing of the Sentry Key
Remote Entry Module (SKREEM), use a DRBllltand
refer to the proper Body Diagnostic Procedures infor-
mation.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Steering Column Opening Cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - REMOVAL).
(3) Remove the steering column upper and lower
shrouds (Refer to 19 - STEERING/COLUMN/UPPER
SHROUD - REMOVAL) and (Refer to 19 - STEER-
ING/COLUMN/LOWER SHROUD - REMOVAL).
(4) Disengage the steering column wire harness
from the Sentry Key Remote Entry Module
(SKREEM).
(5) Remove the one screws securing the SKREEM
to the steering column.
RSVEHICLE THEFT SECURITY8Q-5
SENTRY KEY REMOTE ENTRY MODULE (Continued)
OPERATION
The Mechanical Instrument Cluster (MIC) per-
forms a four second bulb check via PCI communica-
tion with the Sentry Key Remote Entry Module
(SKREEM). After the bulb check, the lamp is con-
trolled according to SKREEM messages. Then, the
SKREEM sends messages to the BCM to operate the
light based upon the results of the Sentry Key
Remote Entry System (SKREES) 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 SKREEM has
detected a system malfunction. If the SKREEM
detects an invalid key when the ignition switch is
moved to the ON position, it sends a message on thePCI bus to the MIC, to flash the light. The SKREEM
can also send a message to flash the light and gen-
erate a single audible chime at the same time. These
two events occurring simultaneously indicate that
the SKIS has been placed into the9Customer Learn9
mode (Refer to 8 - ELECTRICAL/VEHICLE THEFT
SECURITY/TRANSPONDER KEY - STANDARD
PROCEDURE). If the light comes on and stays on
after the power-up test, diagnosis of the SKREES
should be performed using a DRBIIItscan tool and
the appropriate Body Diagnostic Procedures informa-
tion. The light is a Light Emitting Diode (LED) and
is not a serviceable component.
8Q - 8 VEHICLE THEFT SECURITYRS
VTSS/SKIS INDICATOR LAMP (Continued)