2002 JEEP GRAND CHEROKEE head

WARNING: THE FRONT IMPACT SENSOR ENABLES
THE SYSTEM TO DEPLOY THE FRONT SUPPLE-
MENTAL RESTRAINTS. NEVER STRIKE OR DROP
THE FRONT IMPACT SENSOR, AS IT CAN DAMAGE
THE IMPACT SENSOR OR AFFECT ITS CALIBRA-
TION. IF AN IMPACT SENSOR IS ACCIDENTALLY
DROPPED DURING SERVICE, THE SENSOR MUST
BE SCRAPPED AND REPLACED WITH A NEW UNIT.
FAILURE TO OBSERVE THIS WARNING COULD
RESULT IN ACCIDENTAL, INCOMPLETE, OR
IMPROPER FRONT SUPPLEMENTAL RESTRAINT
DEPLOYMENT AND POSSIBLE OCCUPANT INJU-
RIES.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the headlamp mounting module from
the front of the vehicle. (Refer to 23 - BODY/EXTE-
RIOR/HEADLAMP MOUNTING MODULE -
REMOVAL).
(3) Disconnect the right or left headlamp and dash
wire harness connector for the front impact sensor
from the sensor connector receptacle.
(4) Remove the three screws that secure the right
or left front impact sensor and bracket unit to the
right or left radiator support vertical member (Fig.
26).
(5) Remove the right or left front impact sensor
and bracket unit from the front of the vehicle.INSTALLATION
The front and side impact sensors are interchange-
able except that the front impact sensors are serviced
with a right or left mounting bracket, while the side
impact sensors use no mounting bracket. If a front
impact sensor is faulty, but not damaged, the sensor
may be removed from the sensor mounting bracket
and replaced with a side impact sensor. If the front
impact sensor or the sensor mounting bracket are
damaged in any way, or if proper tightening torque of
the screws that secure the sensor to the bracket can-
not be achieved, the front impact sensor and bracket
must be replaced as a unit.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, FRONT IMPACT SENSOR,
SIDE IMPACT SENSOR, SIDE CURTAIN AIRBAG, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BAT-
TERY NEGATIVE (GROUND) CABLE, THEN WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: THE FRONT IMPACT SENSOR ENABLES
THE SYSTEM TO DEPLOY THE FRONT SUPPLE-
MENTAL RESTRAINTS. NEVER STRIKE OR DROP
THE FRONT IMPACT SENSOR, AS IT CAN DAMAGE
THE IMPACT SENSOR OR AFFECT ITS CALIBRA-
TION. IF AN IMPACT SENSOR IS ACCIDENTALLY
DROPPED DURING SERVICE, THE SENSOR MUST
BE SCRAPPED AND REPLACED WITH A NEW UNIT.
FAILURE TO OBSERVE THIS WARNING COULD
RESULT IN ACCIDENTAL, INCOMPLETE, OR
IMPROPER FRONT SUPPLEMENTAL RESTRAINT
DEPLOYMENT AND POSSIBLE OCCUPANT INJU-
RIES.
(1) Position the right or left front impact sensor
and bracket unit to the front of the vehicle (Fig. 26).
(2) Position the right or left front impact sensor
and bracket unit to the right or left radiator support
vertical member.
(3) Loosely install the three screws that secure the
right or left front impact sensor and bracket unit
right or left radiator support vertical member.
Fig. 26 Front Impact Sensor & B Remove/Install
1 - RADIATOR SUPPORT
2 - SCREW (3)
3 - BRACKET
4 - WIRE HARNESS CONNECTOR
5 - IMPACT SENSOR
8O - 26 RESTRAINTSWJ
FRONT IMPACT SENSOR & BRACKET (Continued)

(4) For the right impact sensor and bracket unit,
the tightening sequence for the three screws that
secure it to the right radiator support vertical mem-
ber is from top to bottom. For the left impact sensor
and bracket unit, the tightening sequence for the
three screws that secure it to the left radiator sup-
port vertical member is from bottom to top. Tighten
the screws to 12 N´m (105 in. lbs.).
(5) Reconnect the right or left headlamp and dash
wire harness connector for the front impact sensor to
the sensor connector receptacle.
(6) Reinstall the headlamp mounting module to
the front of the vehicle. (Refer to 23 - BODY/EXTE-
RIOR/HEADLAMP MOUNTING MODULE -
INSTALLATION).
(7) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
FRONT SEAT BELT &
RETRACTOR
REMOVAL
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Adjust the front seat to its most forward posi-
tion for easiest access to the front seat belt lower
anchor and the B-pillar trim.
(2) Disconnect and isolate the battery negative
cable.
(3) Lift the front seat belt lower anchor cover far
enough to access the screw that secures it to the
lower B-pillar (Fig. 27).
(4) Remove the screw that secures the lower
anchor to the B-pillar.(5) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the top of the turning loop
trim cover to unsnap it from the height adjuster and
access the screw that secures the front seat belt turn-
ing loop to the adjuster on the upper B-pillar (Fig.
28).
Fig. 27 Front Seat Belt & Retractor Remove/Install
1 - ADJUSTER
2 - TURNING LOOP
3 - SCREW
4 - LOWER ANCHOR
5 - SCREW
6 - RETRACTOR
Fig. 28 Turning Loop Cover Remove/Install
1 - PILLAR
2 - TRIM COVER
3 - ADJUSTER
WJRESTRAINTS 8O - 27
FRONT IMPACT SENSOR & BRACKET (Continued)

SIDE CURTAIN AIRBAG
DESCRIPTION
Optional side curtain airbags are available for this
model when it is also equipped with dual front air-
bags. These airbags are passive, inflatable, Supple-
mental Restraint System (SRS) components, and
vehicles with this equipment can be readily identified
by a molded identification trim button with the ªSRS
- AIRBAGº logo located on the headliner above each
B-pillar (Fig. 42). This system is designed to reduce
injuries to the vehicle occupants in the event of a
side impact collision.
Vehicles equipped with side curtain airbags have
two individually controlled curtain airbag units.
These airbag units are concealed and mounted above
the headliner where they are each secured to one of
the roof side rails (Fig. 43). Each folded airbag cush-
ion is contained within a long extruded plastic chan-
nel that extends along the roof rail from the A-pillar
at the front of the vehicle to just behind the C-pillar
at the rear of the vehicle. One tether extends down
the A-pillar from the front of the airbag cushion, and
a second tether extends to the roof rail above the
D-pillar. The ends of these tethers are secured to
slots in the sheet metal with metal hooks retained by
plastic anchor clips.
The hybrid-type inflator for each airbag is secured
to the roof rail at the rear of the airbag unit between
the C-pillar and the D-pillar, and is connected to the
airbag cushion by a long tubular manifold. The infla-
tor bracket and the extruded airbag cushion channel
are secured with both plastic push-in fasteners and
screws to the roof rail. A dedicated two-wire take out
and connector of the body wire harness is routed for-
ward from the D-pillar to the airbag inflator.The side curtain airbag unit cannot be adjusted or
repaired and must be replaced if deployed, faulty, or
in any way damaged. Once a side curtain airbag has
been deployed, the complete airbag unit, the head-
liner, the upper A, B, and C-pillar trim, and all other
visibly damaged components must be replaced.
OPERATION
Each side curtain airbag is deployed individually
by an electrical signal generated by the Airbag Con-
trol Module (ACM) to which it is connected through
left or right curtain airbag line 1 and line 2 (or
squib) circuits. The hybrid-type inflator assembly for
each airbag contains a small canister of highly com-
pressed gas. When the ACM sends the proper electri-
cal signal to the airbag inflator, the electrical energy
creates enough heat to ignite chemical pellets within
the inflator. Once ignited, these chemicals burn rap-
idly and produce the pressure necessary to rupture a
containment disk in the pressurized gas canister. The
inflator and gas canister are sealed and connected to
a tubular manifold so that all of the released inert
gas is directed into the folded side curtain airbag
cushion, causing the cushion to inflate.
As the airbag cushion inflates it will drop down
from the roof rail between the edge of the headliner
and the side glass/body pillars to form a curtain-like
cushion to protect the vehicle occupants during a side
impact collision. The front and rear tethers keep the
side curtain bag taut, thus ensuring that the bag will
deploy in the proper position. Following the airbag
deployment, the airbag cushion quickly deflates by
venting the inert gas through the loose weave of the
cushion fabric, and the deflated cushion hangs down
loosely from the roof rail.
REMOVAL
The following procedure is for replacement of a
faulty or damaged side curtain airbag. If the airbag
is faulty or damaged, but not deployed, review the
recommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS). If the side curtain airbag has been
deployed, review the recommended procedures for
service after a supplemental restraint deployment
before removing the airbag from the vehicle. (Refer to
8 - ELECTRICAL/RESTRAINTS - STANDARD PRO-
CEDURE - SERVICE AFTER A SUPPLEMENTAL
RESTRAINT DEPLOYMENT).
Fig. 42 SRS Logo
WJRESTRAINTS 8O - 39

WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, FRONT IMPACT SENSOR,
SIDE IMPACT SENSOR, SIDE CURTAIN AIRBAG, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BAT-
TERY NEGATIVE (GROUND) CABLE, THEN WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: WHEN REMOVING A DEPLOYED AIR-
BAG, RUBBER GLOVES, EYE PROTECTION, AND A
LONG-SLEEVED SHIRT SHOULD BE WORN. THERE
MAY BE DEPOSITS ON THE AIRBAG UNIT AND
OTHER INTERIOR SURFACES. IN LARGE DOSES,
THESE DEPOSITS MAY CAUSE IRRITATION TO THE
SKIN AND EYES.WARNING: USE EXTREME CARE TO PREVENT ANY
FOREIGN MATERIAL FROM ENTERING THE SIDE
CURTAIN AIRBAG, OR BECOMING ENTRAPPED
BETWEEN THE SIDE CURTAIN AIRBAG CUSHION
AND THE HEADLINER. FAILURE TO OBSERVE THIS
WARNING COULD RESULT IN OCCUPANT INJURIES
UPON AIRBAG DEPLOYMENT.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the headliner from the vehicle. (Refer
to 23 - BODY/INTERIOR/HEADLINER - REMOV-
AL).
(3) Disconnect the body wire harness connector for
the side curtain airbag inflator from the inflator con-
nector receptacle (Fig. 44).
(4) Disengage the side curtain airbag rear tether
hook and plastic retainer clip from the slot in the
roof rail near the D-pillar.
(5) Disengage the side curtain airbag front tether
hook and plastic retainer clip from the slot in the
lower A-pillar (Fig. 45).
(6) Disengage the side curtain airbag front tether
plastic retainer from the hole in the upper A-pillar.
Fig. 43 Side Curtain Airbag
1 - NUT (9)
2 - REAR TETHER
3 - SCREW (9)
4 - INFLATOR5 - MANIFOLD
6 - PUSH-IN FASTENER (4)
7 - CHANNEL
8 - FRONT TETHER
8O - 40 RESTRAINTSWJ
SIDE CURTAIN AIRBAG (Continued)

INSTALLATION
The following procedure is for replacement of a
faulty or damaged side curtain airbag. If the airbag
is faulty or damaged, but not deployed, review the
recommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS). If the side curtain airbag has been
deployed, review the recommended procedures for
service after a supplemental restraint deployment
before removing the airbag from the vehicle. (Refer to
8 - ELECTRICAL/RESTRAINTS - STANDARD PRO-
CEDURE - SERVICE AFTER A SUPPLEMENTAL
RESTRAINT DEPLOYMENT).
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, FRONT IMPACT SENSOR,
SIDE IMPACT SENSOR, SIDE CURTAIN AIRBAG, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BAT-
TERY NEGATIVE (GROUND) CABLE, THEN WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: WHEN REMOVING A DEPLOYED AIR-
BAG, RUBBER GLOVES, EYE PROTECTION, AND A
LONG-SLEEVED SHIRT SHOULD BE WORN. THERE
MAY BE DEPOSITS ON THE AIRBAG UNIT AND
OTHER INTERIOR SURFACES. IN LARGE DOSES,
THESE DEPOSITS MAY CAUSE IRRITATION TO THE
SKIN AND EYES.
WARNING: USE EXTREME CARE TO PREVENT ANY
FOREIGN MATERIAL FROM ENTERING THE SIDE
CURTAIN AIRBAG, OR BECOMING ENTRAPPED
BETWEEN THE SIDE CURTAIN AIRBAG CUSHION
AND THE HEADLINER. FAILURE TO OBSERVE THIS
WARNING COULD RESULT IN OCCUPANT INJURIES
UPON AIRBAG DEPLOYMENT.
(1) Position the side curtain airbag into the vehicle
as a unit.(2) Align the push-in fastener that secures the
inflator of the side curtain airbag to the locating hole
in the roof side rail and, using hand pressure, push
firmly on the retainer until it is fully seated (Fig. 45).
(3) Align the three push-in fasteners that secure
the extruded plastic channel of the side curtain air-
bag to the locating holes in the roof side rail and,
using hand pressure, push firmly on each retainer
until it is fully seated.
(4) Install and tighten the nine screws that secure
the side curtain airbag channel and inflator mount-
ing bracket to the spring nuts in the roof side rail.
Tighten the screws to 6 N´m (50 in. lbs.).
(5) Align the side curtain airbag front tether plas-
tic retainer with the hole in the upper A-pillar and,
using hand pressure, push firmly on the retainer
until it is fully seated.
(6) Engage the side curtain airbag front tether
hook and plastic retainer clip into the slot in the
lower A-pillar.
(7) Engage the side curtain airbag rear tether
hook and plastic retainer clip into the slot in the roof
rail near the D-pillar (Fig. 44).
(8) Reconnect the body wire harness connector for
the side curtain airbag inflator to the inflator connec-
tor receptacle.
(9) Reinstall the headliner into the vehicle. (Refer
to 23 - BODY/INTERIOR/HEADLINER - INSTALLA-
TION).
(10) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
SIDE IMPACT SENSOR
DESCRIPTION
Two side impact sensors are used on this model
when it is equipped with the optional side curtain
airbags, one each for the left and right sides of the
vehicle (Fig. 46). These sensors are mounted
remotely from the bi-directional safing sensor that is
internal to the Airbag Control Module (ACM). The
side and front impact sensors are identical in con-
struction and calibration with the exception of the
right-hand and left-hand die cast aluminum mount-
ing brackets to which each front impact sensor is
secured with two screws. The side impact sensors are
secured with two screws to the base of the right and
left B-pillars just below the front seat belt retractors
and behind the lower B-pillar trim within the pas-
senger compartment.
8O - 42 RESTRAINTSWJ
SIDE CURTAIN AIRBAG (Continued)

CONTROL/CENTRAL TIMER MODULE -
DESCRIPTION).
²Combination Flasher (Refer to 8 - ELECTRI-
CAL/LAMPS/LIGHTING - EXTERIOR/COMBINA-
TION FLASHER - DESCRIPTION).
²Door Ajar Switch (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - INTERIOR/DOOR AJAR
SWITCH - DESCRIPTION - DOOR AJAR SWITCH).
²Driver Cylinder Lock Switch (Refer to 8 - ELEC-
TRICAL/POWER LOCKS/DOOR CYLINDER LOCK/
UNLOCK SWITCH - DESCRIPTION).
²Hood Ajar Switch(Refer to 8 - ELECTRICAL/VE-
HICLE THEFT SECURITY/HOOD AJAR SWITCH -
DESCRIPTION).
²Horn Relay (Refer to 8 - ELECTRICAL/HORN/
HORN RELAY - DESCRIPTION).
²Liftgate Ajar Switch (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - INTERIOR/DOOR AJAR
SWITCH - DESCRIPTION - LIFTGATE AJAR
SWITCH).
²Liftgate Flip-Up Glass Ajar Switch(Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - INTERIOR/
DOOR AJAR SWITCH - DESCRIPTION - LIFTGATE
FLIP-UP GLASS AJAR SWITCH).
²Low Beam Headlamp Relay
²VTSS Indicator (Refer to 8 - ELECTRICAL/VE-
HICLE THEFT SECURITY/VTSS INDICATOR -
DESCRIPTION).
Certain functions and features of the VTSS rely
upon resources shared with or controlled by other
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. The
other modules that may affect VTSS operation are:
²Driver Door Module (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/DOOR MOD-
ULE - DESCRIPTION).
²Passenger Door Module (Refer to 8 - ELECTRI-
CAL/ELECTRONIC CONTROL MODULES/DOOR
MODULE - DESCRIPTION).
DESCRIPTION - SENTRY KEY IMMOBILIZER
SYSTEM
Vehicles equipped with the Sentry Key Immobilizer
System (SKIS) can be identified by the presence of
an amber SKIS indicator in the instrument cluster
that will illuminate for about three seconds each
time the ignition switch is turned to the On position,
or by a gray molded rubber cap on the head of the
ignition key. Models not equipped with SKIS still
have a SKIS indicator in the cluster, but it will not
illuminate. Also, models not equipped with the SKIS
have a black molded rubber cap on the head of the
ignition key.
The SKIS includes the following major components,
which are described in further detail elsewhere in
this service manual:²Powertrain Control Module
²Sentry Key Immobilizer Module
²Sentry Key Transponder
²SKIS Indicator
Except for the Sentry Key transponders, which rely
upon Radio Frequency (RF) communication, hard
wired circuitry connects the SKIS components to the
electrical system of the vehicle.Refer to the appropri-
ate wiring information.
OPERATION
OPERATION - VEHICLE THEFT SECURITY
SYSTEM
The Vehicle Theft Security System (VTSS) is
divided into two basic subsystems: Vehicle Theft
Alarm (VTA) and Sentry Key Immobilizer System
(SKIS). The following are paragraphs that briefly
describe the operation of each of those two sub-
systems.
A Body Control Module (BCM) is used to control
and integrate many of the functions and features
included in the Vehicle Theft Security System
(VTSS). In the VTSS, the BCM receives inputs indi-
cating the status of the door ajar switches, the driver
cylinder lock switch, the ignition switch, the liftgate
ajar switches, the liftgate flip-up glass ajar switch,
the power lock switches and, in vehicles so equipped,
the hood ajar switch. The programming in the BCM
allows it to process the information from all of these
inputs and send control outputs to energize or de-en-
ergize the combination flasher, the horn relay (except
vehicles with the premium version of the VTA), and
the VTSS indicator. In addition, in vehicles built for
certain markets where premium versions of the VTA
is required, the BCM also exchanges messages with
the Intrusion Transceiver Module (ITM) over the Pro-
grammable Communications Interface (PCI) data
buss network to provide the features found in this
version of the VTA. The control of these inputs and
outputs are what constitute all of the features of the
VTSS. Following is information on the operation of
each of the VTSS features.
ENABLING
The BCM must have the VTSS function enabled in
order for the VTSS to perform as designed. The logic
in the BCM keeps its VTSS function dormant until it
is enabled using a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
PRE-ARMING
The VTA has a pre-arming sequence. Pre-arming
occurs when a door, the tailgate, or the flip-up glass
is open when the vehicle is locked using a power lock
8Q - 2 VEHICLE THEFT SECURITYWJ
VEHICLE THEFT SECURITY (Continued)

switch, or when the ªLockº button on the Remote
Keyless Entry (RKE) transmitter is depressed. The
powerlock switch will not initiate the pre-arming
sequence if the key is in the ignition switch. When
the VTA is pre-armed, the arming sequence is
delayed until all of the doors, the tailgate and the
flip-up glass are closed.
ARMING
Passive arming of the VTSS occurs when the vehi-
cle is exited with the key removed from the ignition
switch, the headlamps are turned off, and the doors
are locked while they are open using the power lock
switch. The power lock switch will not function if the
key is in the ignition switch or the headlamps are
turned on with the driver side front door open. The
VTSS will not arm if the driver side front door is
locked using the key in the lock cylinder or using the
mechanical lock button. Active arming of the VTSS
occurs when the ªLockº button on the Remote Key-
less Entry (RKE) transmitter is depressed to lock the
vehicle, even if the doors and/or the liftgate are open
when the RKE transmitter Lock button is depressed.
However, the VTSS arming will not be complete until
all of the doors, the liftgate and the liftgate flip-up
glass are closed. On vehicles equipped with the hood
ajar switch, VTSS arming will complete if the hood is
open, but the underhood area will not be protected
unless the hood is closed when the VTSS is armed.
Following successful passive or active VTSS arm-
ing, the VTSS indicator on the top of the instrument
panel will flash rapidly for about sixteen seconds
after the illuminated entry system times out. This
indicates that VTSS arming is in progress. Once the
sixteen second arming function is successfully com-
pleted, the indicator will flash at a slower rate, indi-
cating that the VTSS is armed.
DISARMING
Passive disarming of the VTSS occurs when the
vehicle is unlocked using the key to unlock the driver
side front door. Active disarming of the VTSS occurs
when the vehicle is unlocked by depressing the
ªUnlockº button of the Remote Keyless Entry (RKE)
transmitter. Once the alarm has been activated,
either disarming method will also deactivate the
alarm. Depressing the ªPanicº button on the RKE
transmitter will also disarm the VTSS, but the horn
will continue to pulse and the exterior lamps will
continue to flash for about three minutes as part of
the Panic feature function. The Panic feature is over-
ridden if the ªPanicº button is depressed a second
time, or if a vehicle speed of about 24 kilometers-per-
hour (15 miles-per-hour) is attained.POWER-UP MODE
When the armed VTSS senses that the battery has
been disconnected and reconnected, it enters its pow-
er-up mode. In the power-up mode the alarm system
remains armed following a battery failure or discon-
nect. If the VTSS was armed prior to a battery dis-
connect or failure, the technician or vehicle operator
will have to actively or passively disarm the alarm
system after the battery is reconnected. The pow-
er-up mode will also apply if the battery goes dead
while the system is armed, and battery jump-starting
is then attempted. The VTSS will be armed until it is
actively or passively disarmed. If the VTSS is in the
disarmed mode prior to a battery disconnect or fail-
ure, it will remain disarmed after the battery is
reconnected or replaced, or if jump-starting is
attempted.
ALARM
The VTA alarm output varies by the version of the
VTA with which the vehicle is equipped. In all cases,
the alarm provides both visual and audible outputs;
however, the time intervals of these outputs vary by
the requirements of the market for which the vehicle
is manufactured. In all cases, the visual output will
be a flashing of the exterior lamps. For vehicles
equipped with North American or the base version of
the VTA, the audible output will be the pulsing of the
horn. For vehicles with the premium version of the
VTA, the audible output will be the cycling of the
siren. The inputs that will trigger the alarm include
the door ajar switch, the flip-up glass ajar switch,
and in vehicles built for certain markets where they
are required, the hood ajar switch and the Intrusion
Transceiver Module (ITM).
TAMPER ALERT
The VTSS tamper alert feature will sound the horn
(or the alarm siren for the premium version) three
times upon VTA disarming, if the alarm was trig-
gered and has since timed-out (about eighteen min-
utes). This feature alerts the vehicle operator that
the VTA alarm was activated while the vehicle was
unattended.
INTRUSION ALARM
The Intrusion Alarm is an exclusive feature of the
premium version of the VTA, which is only available
in certain markets, where it is required. When the
VTA is armed, a motion sensor in the Intrusion
Transceiver Module (ITM) monitors the interior of
the vehicle for movement. If motion is detected, the
ITM sends a message to the BCM over the PCI bus
to invoke the visual alarm feature, and sends a mes-
sage to the alarm siren over a dedicated serial bus to
invoke the audible alarm feature. The motion detec-
WJVEHICLE THEFT SECURITY 8Q - 3
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)