2002 JEEP GRAND CHEROKEE Bus

tion feature of the ITM can be disabled by depressing
the ªLockº button on the RKE transmitter three
times or cycling the key in the driver door cylinder
from the center to lock position within fifteen seconds
during VTA arming, while the security indicator is
still flashing rapidly. The VTA provides a single short
siren ªchirpº as an audible conformation that the
motion detect disable request has been received. The
ITM must be electronically enabled in order for the
intrusion alarm to perform as designed. The intru-
sion alarm function of the ITM is enabled on vehicles
equipped with this option at the factory, but a service
replacement ITM must be configured and enabled by
the dealer using the DRBIIItscan tool. Refer to the
appropriate diagnostic information.
OPERATION - SENTRY KEY IMMOBILIZER
SYSTEM
The Sentry Key Immobilizer System (SKIS) is
designed to provide passive protection against unau-
thorized vehicle use by disabling the engine after
about two seconds of running, whenever any method
other than a valid Sentry Key is used to start the
vehicle. The SKIS is considered a passive protection
system because it is always active when the ignition
system is energized and does not require any cus-
tomer intervention. The SKIS uses Radio Frequency
(RF) communication to obtain confirmation that the
key in the ignition switch is a valid key for operating
the vehicle. The microprocessor-based SKIS hard-
ware and software also uses messages to communi-
cate with other modules in the vehicle over the
Programmable Communications Interface (PCI) data
bus. (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/COMMUNICATION - OPERA-
TION).
Pre-programmed Sentry Key transponders are pro-
vided with the vehicle from the factory. Each Sentry
Key Immobilizer Module (SKIM) will recognize a
maximum of eight Sentry Keys. If the customer
would like additional keys other than those provided
with the vehicle, they may be purchased from any
authorized dealer. These additional keys must be pro-
grammed to the SKIM in the vehicle in order for the
system to recognize them as valid keys. This can be
done by the dealer using a DRBIIItscan tool or, if
Customer Learn programming is an available SKIS
feature in the market where the vehicle was pur-
chased, the customer can program the additional
keys, as long as at least two valid Sentry Keys are
already available. (Refer to 8 - ELECTRICAL/VEHI-
CLE THEFT SECURITY - STANDARD PROCE-
DURE - TRANSPONDER PROGRAMMING).
The SKIS performs a self-test each time the igni-
tion switch is turned to the On position, and will
store fault information in the form of DiagnosticTrouble Codes (DTC's) if a system malfunction is
detected. Refer to the appropriate diagnostic informa-
tion.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - VEHICLE THEFT
SECURITY SYSTEM
The VTSS-related hard wired inputs to and out-
puts from the Body Control Module (BCM), the
Driver Door Module (DDM), or the Passenger Door
Module (PDM) may be diagnosed and tested using
conventional diagnostic tools and procedures. Refer
to the appropriate wiring information.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the BCM, the
DDM, the PDM, or the Programmable Communica-
tions Interface (PCI) data bus network. In order to
obtain conclusive testing of the VTSS, the BCM, the
DDM, the PDM, and the PCI data bus network must
also be checked. The most reliable, efficient, and
accurate means to diagnose the VTSS requires the
use of a DRBIIItscan tool and the appropriate diag-
nostic information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
8Q - 4 VEHICLE THEFT SECURITYWJ
VEHICLE THEFT SECURITY (Continued)

(2) Check for battery voltage at the fused B(+) fuse
in the JB. If OK, go to Step 3. If not OK, repair the
open B(+) circuit between the JB fuse and the Power
Distribution Center (PDC).
(3) Check the fused ignition switch output (st-run)
fuse in the JB. If OK, go to Step 4. If not OK, repair
the shorted circuit or component and replace the
faulty fuse.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (st-run) fuse in the JB. If OK, go to Step 5. If
not OK, repair the open fused ignition switch output
(st-run) circuit between the JB fuse and the ignition
switch as required.
(5) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the Sentry Key Immobilizer Module
(SKIM) from the SKIM connector. Check for continu-
ity between the ground circuit of the instrument
panel wire harness connector for the SKIM and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit.
(6) Reconnect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
instrument panel wire harness connector for the
SKIM. If OK, go to Step 7. If not OK, repair the open
fused B(+) circuit between the SKIM and the JB
fuse.
(7) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (st-run) circuit of the instrument panel wire
harness connector for the SKIM. If OK, refer to the
appropriate diagnostic information and use a
DRBIIItscan tool to complete the diagnosis of the
SKIS. If not OK, repair the open fused ignition
switch output (st-run) circuit between the SKIM and
the JB fuse.
SKIS INDICATOR FLASHES OR LIGHTS SOLID FOLLOWING
BULB TEST
A SKIS indicator that flashes following a successful
bulb test indicates that an invalid key has been
detected, or that a key-related fault has been set. A
SKIS indicator that lights solid following a successful
bulb test indicates that the SKIM has detected a sys-
tem malfunction or that the SKIS is inoperative. In
either case, fault information will be stored in the
SKIM memory. For retrieval of this fault information
and further diagnosis of the SKIS, the PCI data bus,
the SKIM message outputs to the instrument cluster,
the SKIM message outputs to the Body Control Mod-
ule (BCM), or the message inputs and outputs
between the SKIM and the Powertrain Control Mod-
ule (PCM), a DRBIIItscan tool and the appropriate
diagnostic information are required. Following are
preliminary troubleshooting guidelines to be followed
during diagnosis using a DRBIIItscan tool:(1) Using the DRBIIItscan tool, read and record
the faults as they exist in the SKIM when you first
begin your diagnosis of the vehicle. It is important to
document these faults because the SKIM does not
differentiate between historical and active faults. If
this problem turns out to be an intermittent condi-
tion, this information may become invaluable to your
diagnosis.
(2) Using the DRBIIItscan tool, erase all of the
faults from the SKIM.
(3) Cycle the ignition switch to the Off position,
then back to the On position.
(4) Using the DRBIIItscan tool, read any faults
that are now present in the SKIM. These are the
active faults.
(5) Using this active fault information, refer to the
proper procedure in the appropriate diagnostic infor-
mation for the additional specific diagnostic steps.
STANDARD PROCEDURE
STANDARD PROCEDURE - SKIS
INITIALIZATION
The Sentry Key Immobilizer System (SKIS) must
be initialized following a Sentry Key Immobilizer
Module (SKIM) replacement. SKIS initialization
requires the use of a DRBIIItscan tool. Initialization
will also require that you have access to the unique
four-digit PIN code that was assigned to the original
SKIM. The PIN codemustbe used to enter the
Secured Access Mode in the SKIM. This PIN number
may be obtained from the vehicle owner, from the
original vehicle invoice, or from the DaimlerChrysler
Customer Center. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES - STANDARD PRO-
CEDURE - PCM/SKIM PROGRAMMING).
NOTE: If a Powertrain Control Module (PCM) is
replaced on a vehicle equipped with the Sentry Key
Immobilizer System (SKIS), the unique Secret Key
data must be transferred from the Sentry Key
Immobilizer Module (SKIM) to the new PCM using
the PCM replacement procedure. This procedure
also requires the use of a DRBIIITscan tool and the
unique four-digit PIN code to enter the Secured
Access Mode in the SKIM. Refer to the appropriate
diagnostic information for the proper PCM replace-
ment procedures.
STANDARD PROCEDURE - SENTRY KEY
TRANSPONDER PROGRAMMING
All Sentry Keys included with the vehicle are pre-
programmed to work with the Sentry Key Immobi-
lizer System (SKIS) when it is shipped from the
8Q - 6 VEHICLE THEFT SECURITYWJ
VEHICLE THEFT SECURITY (Continued)

INSTALLATION - HOOD AJAR SWITCH
STRIKER
(1) Align the three integral retainers of the hood
ajar switch striker with their mounting holes in the
inner hood panel reinforcement (Fig. 4).
(2) Using hand pressure, firmly press the hood
ajar switch striker against the inner hood panel rein-
forcement until all of the striker retainers are fully
engaged in their mounting holes.
(3) Close and latch the hood.
INTRUSION TRANSCEIVER
MODULE
DESCRIPTION
An Intrusion Transceiver Module (ITM) is part of
the premium version of the Vehicle Theft Alarm
(VTA) in the Vehicle Theft Security System (VTSS)
(Fig. 5). The premium version of the VTA is only
available in vehicles built for certain markets, where
the additional features offered by this system are
required. The ITM is located in the passenger com-
partment. This unit is designed to provide interior
motion detection, and serve as an interface between
the Body Control Module (BCM) and the alarm siren
module.
The ITM is concealed beneath a dedicated molded
plastic trim cover that approximates the size and
shape of a typical dome lamp housing. However,
rather than a lens, the ITM features three sets of
louvered openings. One set of louvered openings is
located at each outboard end of the center rib, while
the third set is centered. Each of the louvered open-
ings is covered on the inside by a sight shield thatextends the length of the center rib. The module is
secured to a mounting bracket above the headliner
(Fig. 6).
Concealed within the housing is the circuitry of the
ITM which includes a microprocessor, and an ultra-
sonic receive transducer. Both the transmit trans-
ducer on the right side of the module and the receive
transducer on the ITM circuit board are aimed
through two small round holes in the sight shield of
the trim cover. The ITM is connected to the vehicle
electrical system by a take out and connector of the
overhead wire harness that is integral to the head-
liner.
The ITM unit cannot be adjusted or repaired and,
if faulty or damaged, it must be replaced. The ITM is
serviced as a unit with the trim cover.
OPERATION
The microprocessor in the Intrusion Transceiver
Module (ITM) contains the motion sensor logic cir-
cuits and controls all of the features of the premium
version of the Vehicle Theft Alarm (VTA). The ITM
uses On-Board Diagnostics (OBD) and can communi-
cate with other modules in the vehicle as well as
with the DRBIIItscan tool using the Programmable
Communications Interface (PCI) data bus network.
This method of communication is used by the ITM to
communicate with the Body Control Module (BCM)
and for diagnosis and testing. The ITM also commu-
nicates with the alarm siren over a dedicated serial
bus circuit.
Fig. 5 INTRUSION TRANSCEIVER MODULE
1 - ITM
2 - HEADLINER
Fig. 6 INTRUSION TRANSCEIVER MODULE
1 - TRIM COVER
2 - CONNECTOR RECEPTACLE
3 - HOUSING
4 - SCREW (4)
5 - SERVICE HOLE (2)
6 - LATCH FEATURE (4)
WJVEHICLE THEFT SECURITY 8Q - 11
HOOD AJAR SWITCH (Continued)

The ITM microprocessor continuously monitors
inputs from its on-board motion sensor as well as
inputs from the BCM and the alarm siren module.
The ITM motion sensor transmits ultrasonic signals
into the vehicle cabin through a transmit transducer,
then listens to the returning signals as the bounce off
of objects in the vehicle interior. If an object is mov-
ing in the interior, a detection circuit in the ITM
senses this movement through the modulation of the
returning ultrasonic signals that occurs due to the
Doppler effect. The motion detect function of the ITM
can be disabled by depressing the ªLockº button on
the Remote Keyless Entry (RKE) transmitter three
times within fifteen seconds, while the security indi-
cator is still flashing rapidly or by cycling the key in
the driver door cylinder from the center to the lock
position. The ITM will signal the alarm siren module
to provide a single siren ªchirpº as an audible confir-
mation that the motion sensor function has been dis-
abled.
If movement is detected, the ITM sends an mes-
sage to the BCM over the PCI data bus to flash the
exterior lighting and send a message to the alarm
siren module over a dedicated serial bus line to
sound the siren. When the BCM detects a breach in
the perimeter protection through a door, tailgate,
flip-up glass, or hood ajar switch input, it sends an
message to the ITM and the ITM sends an message
to the BCM over the PCI data bus to flash the exte-
rior lighting and send a message to the alarm siren
module over a dedicated serial bus line to sound the
siren. The ITM also monitors inputs from the alarm
siren module for siren battery or siren input/output
circuit tamper alerts, and siren battery condition
alerts, then sets active and stored Diagnostic Trouble
Codes (DTC) for any monitored system faults it
detects. An active fault only remains for the current
ignition switch cycle, while a stored fault causes a
DTC to be stored in memory by the ITM. If a fault
does not reoccur for fifty ignition cycles, the ITM will
automatically erase the stored DTC.
The ITM is connected to the vehicle electrical sys-
tem through the overhead wire harness. The ITM
receives battery voltage on a B(+) circuit through a
fuse in the Junction Block (JB), and is grounded to
the chassis at G303. These connections allow the
ITM to remain operational, regardless of the ignition
switch position. The hard wired inputs and outputs
for the ITM may be diagnosed and tested using con-
ventional diagnostic tools and procedures. However,
conventional diagnostic methods will not prove con-
clusive in the diagnosis of the ITM, the PCI data bus
network, or the electronic message inputs to and out-
puts from the ITM. The most reliable, efficient, and
accurate means to diagnose the ITM, the PCI data
bus network, and the message inputs to and outputsfrom the ITM requires the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) While pulling downward lightly on the rear cor-
ner of the Intrusion Transceiver Module (ITM) trim
cover, insert a small thin-bladed screwdriver through
each of the service holes on the rear edge of the trim
cover to release the two integral rear latch features
of the module from the mounting bracket above the
headliner (Fig. 7).
(3) Pull the ITM trim cover rearward far enough
to disengage the two front latch features of the mod-
ule from the mounting bracket above the headliner.
(4) Pull the ITM and trim cover down from the
headliner far enough to access and disconnect the
overhead wire harness connector for the ITM from
the module connector.
(5) Remove the ITM from the headliner.
INSTALLATION
(1) Position the Intrusion Transceiver Module
(ITM) to the headliner.
(2) Reconnect the overhead wire harness connector
for the ITM to the module connector.
(3) Align the two front latch features of the ITM
with the two front latch receptacles of the mounting
bracket above the headliner (Fig. 8).
(4) Push the ITM trim cover forward far enough to
insert the two rear latch features of the module into
Fig. 7 INTRUSION TRANSCEIVER MODULE
REMOVE
1 - SMALL SCREWDRIVER
2 - HEADLINER
3 - SERVICE HOLES
4 - ITM
8Q - 12 VEHICLE THEFT SECURITYWJ
INTRUSION TRANSCEIVER MODULE (Continued)

the two rear latch receptacles of the mounting
bracket above the headliner.
(5) Push upward firmly and evenly on the rear
edge of the ITM trim cover until the two rear latch
features of the module are engaged and latched in
the mounting bracket above the headliner.
(6) Reconnect the battery negative cable.
NOTE: If the Intrusion Transceiver Module (ITM) has
been replaced with a new unit, the new ITM MUST
be initialized before the Vehicle Theft Security Sys-
tem can operate as designed. The use of a DRBIIIT
scan tool is required to initialize the ITM. Refer to
the appropriate diagnostic information.
SIREN
DESCRIPTION
An alarm siren module is part of the premium ver-
sion of the Vehicle Theft Alarm (VTA) in the Vehicle
Theft Security System (VTSS) (Fig. 9). The premium
version of the VTA is only available in vehicles built
for certain markets, where the additional features
offered by this system are required. The alarm siren
module is located in the right front frame rail. This
unit is designed to provide the audible alert require-
ments for the premium VTA.
The alarm siren module consists of microprocessor,
the siren, and a nickel metal hydride backup battery.
All of the alarm module components are protected
and sealed within the housing.The alarm siren module cannot be repaired or
adjusted and, if faulty or damaged, it must be
replaced.
OPERATION
The microprocessor within the alarm siren module
provides the siren unit features and functions based
upon internal programming and arm and disarm
messages received from the Intrusion Transceiver
Module (ITM) over a dedicated serial bus communi-
cation circuit. The alarm siren module will self-detect
problems with its internal and external power supply
and communication circuits, then send messages
indicating the problem to the ITM upon receiving a
request from the ITM. The ITM will store a Diagnos-
tic Trouble Code (DTC) for a detected alarm siren
module fault that can be retrieved with the DRBIIIt
scan tool over the Programmable Communications
Interface (PCI) data bus.
When the premium version of the Vehicle Theft
Alarm (VTA) is armed, the alarm siren module con-
tinuously monitors inputs from the ITM for messages
to sound its siren and enters its auto-detect mode.
While in the auto-detect mode, if the alarm siren
module detects that its power supply or communica-
tion circuits are being tampered with or have been
sabotaged, it will sound an alarm and continue to
operate through its on-board backup battery. If the
arm siren module is in its disarmed mode when its
power supply or communication circuits are inter-
rupted, the siren will not sound. The alarm module
will also notify the ITM when the backup battery
requires charging, and the ITM will send a message
that will allow the backup battery to be charged
through the battery voltage and ground circuits to
the alarm module only when the ignition switch is in
the On position and the engine is running. This will
prevent the charging of the alarm backup battery
from depleting the charge in the main vehicle battery
while the vehicle is not being operated.
The alarm siren module receives battery voltage
through a fuse in the Power Distribution Center
(PDC), and is grounded to the chassis. These connec-
tions allow the alarm siren module to remain opera-
tional, regardless of the ignition switch position. The
hard wired inputs and outputs for the alarm siren
module may be diagnosed and tested using conven-
tional diagnostic tools and procedures. However, con-
ventional diagnostic methods will not prove
conclusive in the diagnosis of the internal circuitry or
the backup battery of the alarm siren module, the
ITM, the serial bus communication line, or the mes-
sage inputs to and outputs from the alarm siren
module. The most reliable, efficient, and accurate
means to diagnose the alarm siren module, the ITM,
the serial bus communication line, and the electronic
Fig. 8 INTRUSION TRANSCEIVER MODULE
RETAINER RING
1 - STAMPED NUT (2)
2 - MOUNTING BRACKET
3 - HEADLINER
4 - LATCH RECEPTACLES (4)
WJVEHICLE THEFT SECURITY 8Q - 13
INTRUSION TRANSCEIVER MODULE (Continued)

message inputs to and outputs from the alarm siren
module requires the use of a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the alarm siren module wiring har-
ness connector. (Fig. 9).
(3) Remove the screws that secure the alarm siren
module to the left frame rail.
(4) Remove the alarm siren module.
INSTALLATION
(1) Position the alarm siren module on to the left
frame rail. (Fig. 9).
(2) Install and tighten the screws that secure the
alarm siren moduleto the frame rail. Tighten the
screws to 6 N´m (50 in. lbs.).
(3) Reconnect the alarm siren module wiring har-
ness connector.
(4) Reconnect the battery negative cable.
NOTE: If the alarm siren module has been replaced
with a new unit, the new unit MUST be configured
in the Intrusion Transceiver Module (ITM) before the
Vehicle Theft Security System can operate as
designed. The use of a DRBIIITscan tool is requiredto configure the alarm siren module settings in the
ITM. Refer to the appropriate diagnostic informa-
tion.
SKIS INDICATOR LAMP
DESCRIPTION
A Sentry Key Immobilizer System (SKIS) indicator
lamp is standard equipment on all instrument clus-
ters, but is only functional on vehicles equipped with
the optional SKIS. The amber SKIS indicator lamp is
located to the right of the oil pressure gauge.
OPERATION
The Sentry Key Immobilizer System (SKIS) indica-
tor lamp gives an indication to the vehicle operator of
the status of the SKIS. This lamp is controlled by a
transistor on the instrument cluster circuit board
based upon messages received by the cluster from
the Sentry Key Immobilizer Module (SKIM) over the
Programmable Communications Interface (PCI) data
bus. The SKIS indicator lamp bulb receives battery
current on the instrument cluster circuit board
through the fused ignition switch output (st-run) cir-
cuit whenever the ignition switch is in the On or
Start positions. The lamp bulb only illuminates when
it is provided a path to ground by the instrument
cluster transistor. The instrument cluster will turn
on the SKIS indicator lamp for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position, the SKIM tells the cluster
to illuminate the lamp for about three seconds.
²SKIS Lamp-On Message- Each time the clus-
ter receives a SKIS lamp-on message from the SKIM,
the lamp will be illuminated. The lamp can be
flashed on and off, or illuminated solid, as dictated
by the message from the SKIM. For more informa-
tion on the SKIS and the SKIS lamp control param-
eters, (Refer to 8 - ELECTRICAL/VEHICLE THEFT
SECURITY - OPERATION - SENTRY KEY IMMO-
BILIZER SYSTEM). The lamp remains illuminated
until the cluster receives a lamp-off message from
the SKIM or until the ignition switch is turned to the
Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the lamp will be turned on
for the duration of the test to confirm the functional-
ity of the lamp and the cluster.
The SKIM performs a self-test each time the igni-
tion switch is turned to the On position to decide
whether the system is in good operating condition.
The SKIM then sends a message to the instrument
cluster. If the SKIS indicator lamp fails to light dur-
ing the bulb test, replace the bulb. For further diag-
nosis of the SKIS indicator lamp or the instrument
Fig. 9 Siren Remove/Install
1 - SIREN
2 - FRAME
8Q - 14 VEHICLE THEFT SECURITYWJ
SIREN (Continued)

cluster circuitry that controls the lamp, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). If the instrument cluster turns
on the SKIS indicator lamp after the bulb test, either
solid or flashing, it indicates that a SKIS malfunction
has occurred or that the SKIS is inoperative. For
proper diagnosis of the SKIS, the PCI data bus, or
the message inputs to the instrument cluster that
control the SKIS indicator lamp, a DRBIIItscan tool
and the appropriate diagnostic information are
required.
TRANSPONDER KEY
DESCRIPTION
Each ignition key used in the Sentry Key Immobi-
lizer System (SKIS) has an integral transponder chip
(Fig. 10). Ignition keys with this feature can be
readily identified by a gray rubber cap molded onto
the head of the key, while conventional ignition keys
have a black molded rubber cap. The transponder
chip is concealed beneath the molded rubber cap,
where it is molded into the head of the metal key.
Each new Sentry Key has a unique transponder iden-
tification code permanently programmed into it by
the manufacturer. The Sentry Key transponder if
faulty or damaged, must be replaced.
OPERATION
When the ignition switch is turned to the On posi-
tion, the Sentry Key Immobilizer Module (SKIM)communicates through its antenna with the Sentry
Key transponder using a Radio Frequency (RF) sig-
nal. The SKIM then waits for a RF response from the
transponder through the same antenna. The Sentry
Key transponder chip is within the range of the
SKIM transceiver antenna ring when it is inserted
into the ignition lock cylinder. The SKIM determines
whether a valid key is present in the ignition lock
cylinder based upon the response from the transpon-
der. If a valid key is detected, that fact is communi-
cated by the SKIM to the Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus, and the PCM allows the
engine to continue running. If the PCM receives an
invalid key message, or receives no message from the
SKIM over the PCI data bus, the engine will be dis-
abled after about two seconds of operation. The Elec-
troMechanical Instrument Cluster (EMIC) will also
respond to the invalid key message on the PCI data
bus by flashing the SKIS indicator on and off.
Each Sentry Key has a unique transponder identi-
fication code permanently programmed into it by the
manufacturer. Likewise, the SKIM has a unique
Secret Key code programmed into it by the manufac-
turer. When a Sentry Key is programmed into the
memory of the SKIM, the SKIM stores the transpon-
der identification code from the Sentry Key, and the
Sentry Key learns the Secret Key code from the
SKIM. Once the Sentry Key learns the Secret Key
code of the SKIM, it is permanently stored in the
memory of the transponder. Therefore, once a Sentry
Key has been programmed to a particular vehicle, it
cannot be used on any other vehicle. (Refer to 8 -
ELECTRICAL/VEHICLE THEFT SECURITY -
STANDARD PROCEDURE - TRANSPONDER PRO-
GRAMMING).
VTSS INDICATOR
DESCRIPTION
The Vehicle Theft Security System (VTSS) indica-
tor consists of a red Light-Emitting Diode that is
mounted and integral to the automatic headlamp
light sensor photo diode unit, which is located on the
top of the instrument panel. The remainder of the
housing including the mount and the electrical con-
nection are concealed beneath the instrument panel
top cover.
The VTSS indicator cannot be adjusted or repaired
the entire automatic headlamp light sensor/VTSS
indicator must be replaced. (Refer to 8 - ELECTRI-
CAL/LAMPS/LIGHTING - EXTERIOR/AUTO HEAD-
LAMP SENSOR - REMOVAL).
Fig. 10 Sentry Key Immobilizer Transponder
1 - MOLDED CAP
2 - TRANSPONDER CHIP
3 - MOLDED CAP REMOVED
4 - TRANSPONDER KEY
WJVEHICLE THEFT SECURITY 8Q - 15
SKIS INDICATOR LAMP (Continued)

tem functions, as well as separate hard wired sense
inputs to the BCM for the high speed continuous
wipe and front washer system functions.
The front wiper and washer system will only oper-
ate when the ignition switch is in the Accessory or
On positions. Battery current is directed from a B(+)
fuse in the Power Distribution Center (PDC) to the
wiper and washer system circuit breaker in the Junc-
tion Block (JB) through a fused ignition switch out-
put (run-acc) circuit. The automatic resetting circuit
breaker then provides battery current through a
fused ignition switch output (run-acc) circuit to the
wiper on/off relay, and the park switch in the front
wiper motor. A separate fuse in the JB provides bat-
tery current through another fused ignition switch
output (run-acc) circuit to the right multi-function
switch. The right multi-function switch circuitry uses
this battery feed to directly control the operation of
the front washer pump/motor unit. The BCM uses
low side drivers to control front wiper system opera-
tion by energizing or de-energizing the wiper high/
low and wiper on/off relays.
The hard wired circuits and components of the
front wiper and washer system may be diagnosed
and tested using conventional diagnostic tools and
procedures. However, conventional diagnostic meth-
ods may not prove conclusive in the diagnosis of the
Body Control Module (BCM), or the inputs to or out-
puts from the BCM that control the front wiper and
washer system operating modes. The most reliable,
efficient, and accurate means to diagnose the BCM,
or the BCM inputs and outputs related to the various
front wiper and washer system operating modes
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
Following are paragraphs that briefly describe the
operation of each of the front wiper and washer sys-
tem operating modes.
CONTINUOUS WIPE MODE
When the Low position of the control knob on the
control stalk of the right (wiper) multi-function
switch is selected, the Body Control Module (BCM)
energizes the wiper on/off relay. This directs battery
current through the normally open contacts of the
energized wiper on/off relay and the normally closed
contacts of the de-energized wiper high/low relay to
the low speed brush of the front wiper motor, causing
the front wipers to cycle at low speed. When the
High position of the control knob is selected, the
BCM energizes both the wiper on/off relay and the
wiper high/low relay. This directs battery current
through the normally open contacts of the energized
wiper on/off relay and the normally open contacts of
the energized wiper high/low relay to the high speedbrush of the front wiper motor, causing the front wip-
ers to cycle at high speed.
When the Off position of the control knob is
selected, the BCM de-energizes both the wiper on/off
and wiper high/low relays, then one of two events
will occur. The event that will occur depends upon
the position of the wiper blades on the windshield at
the moment that the control knob Off position is
selected. If the wiper blades are in the down position
on the windshield when the Off position is selected,
the park switch that is integral to the front wiper
motor is closed to ground and the wiper motor ceases
to operate. If the wiper blades are not in the down
position on the windshield at the moment the Off
position is selected, the park switch is closed to bat-
tery current from the fused ignition switch output
(run-acc) circuit of the front wiper motor. The park
switch directs this battery current to the low speed
brush of the wiper motor through the wiper park
switch sense circuit and the normally closed contacts
of the wiper on/off and wiper high/low relays. This
causes the wiper motor to continue running at low
speed until the wiper blades are in the down position
on the windshield and the park switch is again
closed to ground.
INTERMITTENT WIPE MODE
On models not equipped with the optional auto-
matic wiper system, when the control knob on the
control stalk of the right (wiper) multi-function
switch is moved to one of the five Delay interval posi-
tions, the BCM electronic intermittent wipe logic cir-
cuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The BCM monitors the chang-
ing state of the wiper motor park switch through a
hard wired front wiper park switch sense circuit
input. This input allows the BCM to determine the
proper intervals at which to energize and de-energize
the wiper on/off relay to operate the front wiper
motor intermittently for one low speed cycle at a
time. The BCM logic is also programmed to provide
an immediate wipe cycle and begin a new delay
interval timing cycle each time a shorter delay inter-
val is selected, and to add the remaining delay tim-
ing interval to the new delay interval timing before
the next wipe cycle occurs each time a longer delay
interval is selected.
The intermittent wipe mode delay times are speed
sensitive. The BCM monitors vehicle speed messages
received from the Powertrain Control Module (PCM)
over the Programmable Communications Interface
(PCI) data bus network in order to provide the speed
sensitive delay intervals. Above about sixteen kilome-
ters-per-hour (ten miles-per-hour) the delay is driver
adjustable from about one-half second to about eigh-
WJFRONT WIPERS/WASHERS 8R - 5
FRONT WIPERS/WASHERS (Continued)