2002 JEEP GRAND CHEROKEE Electrical Theft Security

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)

OPERATION
The Vehicle Theft Security System (VTSS) indica-
tor gives a visible indication of the VTSS arming sta-
tus. One side of Light-Emittiong Diode (LED) in the
VTSS indicator is connected to unswitched battery
current through a fused B(+) circuit and a fuse in the
Junction Block (JB). The other side of the LED is
hard wired to the Body Control Module (BCM), which
controls the operation of the VTSS indicator by pull-
ing this side of the LED circuit to ground. When the
VTSS arming is in progress, the BCM will flash the
LED rapidly on and off for about fifteen seconds.
When the VTSS has been successfully armed, the
BCM will flash the LED on and off continually at a
much slower rate until the VTSS has been disarmed.
The VTSS indicator can be diagnosed using conven-
tional diagnostic tools and methods.
DIAGNOSIS AND TESTING - VTSS INDICATOR
The diagnosis found here addresses an inoperative
Vehicle Theft Security System (VTSS) indicator con-
dition. If the problem being diagnosed is related to
indicator accuracy, be certain to confirm that the
problem is with the indicator and not with an inop-
erative VTSS. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY - DIAGNOSIS AND TESTING -
VEHICLE THEFT SECURITY SYSTEM). If no VTSS
problem is found, the following procedure will help to
locate a short or open in the VTSS indicator control
circuit. Refer to the appropriate wiring 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.
(1) Check the fused B(+) fuse in the Junction
Block (JB). If OK, go to Step 2. If not OK, repair the
shorted circuit or component and replace the faulty
fuse.
(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 fused B(+) circuit between the JB and the
Power Distribution Center (PDC).
(3) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the automatic headlamp light sensor/
VTSS indicator from the automatic headlamp light
sensor/VTSS indicator pigtail wire connector. Recon-
nect the battery negative cable. Check for battery
voltage at the fused B(+) circuit cavity of the instru-
ment panel wire harness connector for the automatic
headlamp light sensor/VTSS indicator. If OK, go to
Step 4. If not OK, repair the open fused B(+) circuit
between the VTSS indicator and the JB.
(4) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the JB from the JB connector recepta-
cle. Check for continuity between the VTSS indicator
driver circuit cavity of the instrument panel wire
harness connector for the automatic headlamp light
sensor/VTSS indicator and a good ground. There
should be no continuity. If OK, go to Step 5. If not
OK, repair the shorted VTSS indicator driver circuit
between the VTSS indicator and the JB.
(5) Check for continuity between the VTSS indica-
tor driver circuit of the instrument panel wire har-
ness connector for the automatic headlamp light
sensor/VTSS indicator and the instrument panel wire
harness connector for the JB. There should be conti-
nuity. If OK, replace the faulty VTSS indicator. If not
OK, repair the open VTSS indicator driver circuit
between the VTSS indicator and the JB.
8Q - 16 VEHICLE THEFT SECURITYWJ
VTSS INDICATOR (Continued)

INSTALLATION
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.
(1) If the vehicle is not equipped with the optional
automatic headlamps light sensor/vehicle theft secu-
rity system indicator, be certain that the hole plug is
installed in the clearance hole located to the out-
board side of the driver side defroster outlet in the
instrument panel top cover (Fig. 22).
(2) Before installing the top cover onto the top of
the instrument panel, be certain that the rubber top
cover seal is properly positioned on the forward edge
of the top cover panel.
(3) Position the top cover onto the top of the
instrument panel.
(4) Align the four snap clips on the top cover with
the snap clip receptacles in the instrument panel top
pad.
(5) Press firmly downward on the top cover over
each of the four snap clip locations until each of the
snap clips is fully seated in their receptacles in the
instrument panel top pad.
(6) Reconnect the battery negative cable.
INSTRUMENT PANEL TOP PAD
REMOVAL
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.(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim from the right and left A-pil-
lars. (Refer to 23 - BODY/INTERIOR/A-PILLAR
TRIM - REMOVAL).
(3) Remove the top cover from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL TOP COVER - REMOVAL).
(4) Remove the four nuts that secure the instru-
ment panel top pad to the studs on the dash panel
near the windshield fence line (Fig. 23).
(5) Remove the speakers from the instrument
panel top pad. (Refer to 8 - ELECTRICAL/AUDIO/
SPEAKER - REMOVAL - INSTRUMENT PANEL
SPEAKER).
(6) Disengage the retainer that secures each of the
two instrument panel wire harness speaker take outs
to the mounting hole in the instrument panel top
pad. Tuck the loose ends of these speaker take outs
down the defroster ducts to keep them out of the way
during the remainder of this procedure.
(7) If the vehicle is so equipped, remove the two
screws that secure the automatic headlamp light sen-
sor/vehicle theft security system indicator unit to the
instrument panel top pad just outboard of the driver
side defroster outlet. Move the sensor/indicator unit
towards the windshield to keep it out of the way dur-
ing the remainder of this procedure.
(8) Remove the cluster bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(9) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(10) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(11) Roll the glove box down from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - STANDARD PROCEDURE - GLOVE
BOX ROLL DOWN).
(12) Remove the end cap from the passenger side
lower outboard end of the instrument panel. (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL END CAP - REMOVAL).
(13) Remove the lower right center bezel from the
instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/IP LOWER RIGHT CENTER BEZEL
- REMOVAL).
(14) Remove the glove box lamp and switch from
the instrument panel. (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - INTERIOR/GLOVE BOX
LAMP/SWITCH - REMOVAL).
23 - 52 INSTRUMENT PANEL SYSTEMWJ
INSTRUMENT PANEL TOP COVER (Continued)