2002 JEEP GRAND CHEROKEE Trim

SEAT BELT TURNING LOOP
ADJUSTER
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) Remove the turning loop from the front or rear
seat belt turning loop adjuster. (Refer to 8 - ELEC-
TRICAL/RESTRAINTS/FRONT SEAT BELT &
RETRACTOR - REMOVAL) or (Refer to 8 - ELEC-
TRICAL/RESTRAINTS/REAR OUTBOARD SEAT
BELT & RETRACTOR - REMOVAL).
(2) Remove the trim from the upper B-pillar (front
seat belt adjuster) or upper C-pillar (rear seat belt
adjuster). (Refer to 23 - BODY/INTERIOR/B-PILLAR
UPPER TRIM - REMOVAL) or (Refer to 23 - BODY/
INTERIOR/C-PILLAR TRIM - REMOVAL).
(3) Remove the screw that secures the upper end
of the front or rear turning loop adjuster to the pillar
(Fig. 41).
(4) Pull the upper end of the turning loop adjuster
away from the pillar far enough to disengage the
hooks on the lower end of the adjuster from the slots
in the pillar.
(5) Remove the turning loop adjuster from the
B-pillar (front seat belt) or C-pillar (rear seat belt).
INSTALLATION
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 THATHAS 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) Position the turning loop adjuster to the B-pil-
lar (front seat belt) or C-pillar (rear seat belt).
(2) Engage the hooks on the lower end of the
adjuster into the slots in the pillar (Fig. 41).
(3) Tilt the upper end of the turning loop adjuster
into position against the pillar.
(4) Install and tighten the screw that secures the
upper end of the front or rear height adjuster to the
pillar. Tighten the screw to 43 N´m (32 ft. lbs.).
(5) Reinstall the trim onto the upper B-pillar
(front seat belt adjuster) or upper C-pillar (rear seat
belt adjuster). (Refer to 23 - BODY/INTERIOR/B-
PILLAR UPPER TRIM - INSTALLATION) or (Refer
to 23 - BODY/INTERIOR/C-PILLAR TRIM -
INSTALLATION).
(6) Reinstall the front or rear seat belt turning
loop to the adjuster. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/FRONT SEAT BELT & RETRACTOR -
INSTALLATION) or (Refer to 8 - ELECTRICAL/RE-
STRAINTS/REAR OUTBOARD SEAT BELT &
RETRACTOR - INSTALLATION).
Fig. 41 Seat Belt Turning Loop Adjuster - Typical
1 - SCREW (1)
2 - ADJUSTER
3 - LEVER
4 - SLOTS (2)
5 - HOOKS (2)
8O - 38 RESTRAINTSWJ

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

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)

The impact sensor housing has an integral connec-
tor receptacle and two integral mounting ears, each
with a metal sleeve to provide crush protection. A
cavity in the center of the molded black plastic
impact sensor housing contains the electronic cir-
cuitry of the sensor which includes an electronic com-
munication chip and an electronic impact sensor.
Potting material fills the cavity to seal and protect
the internal electronic circuitry and components. The
side impact sensors are each connected to the vehicle
electrical system through a dedicated take out and
connector of the airbag overlay wire harness.
The side impact sensors cannot be repaired or
adjusted and, if damaged or faulty, they must be
replaced.
OPERATION
The side impact sensors are electronic accelerome-
ters that sense the rate of vehicle deceleration, which
provides verification of the direction and severity of
an impact. Each sensor also contains an electronic
communication chip that allows the unit to commu-
nicate the sensor status as well as sensor fault infor-
mation to the microprocessor in the Airbag Control
Module (ACM). The ACM microprocessor continu-
ously monitors all of the passive restraint system
electrical circuits to determine the system readiness.
If the ACM detects a monitored system fault, it sets
a Diagnostic Trouble Code (DTC) and controls the
airbag indicator operation accordingly.
The impact sensors each receive battery current and
ground through dedicated left and right sensor plus
and minus circuits from the ACM. The impact sensors
and the ACM communicate by modulating the voltage
in the sensor plus circuit. The hard wired circuits
between the side impact sensors and the ACM may bediagnosed and tested using conventional diagnostic
tools and procedures. However, conventional diagnos-
tic methods will not prove conclusive in the diagnosis
of the ACM or the impact sensors. The most reliable,
efficient, and accurate means to diagnose the impact
sensors, the ACM, and the electronic message commu-
nication between the sensors and the ACM requires
the use of a DRBIIItscan tool. Refer to the appropri-
ate diagnostic information.
REMOVAL
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 SIDE IMPACT SENSOR ENABLES
THE SYSTEM TO DEPLOY THE SIDE CURTAIN AIR-
BAG. NEVER STRIKE OR DROP THE SIDE IMPACT
SENSOR, AS IT CAN DAMAGE THE IMPACT SEN-
SOR OR AFFECT ITS CALIBRATION. 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 ACCI-
DENTAL, INCOMPLETE, OR IMPROPER SIDE CUR-
TAIN AIRBAG DEPLOYMENT AND POSSIBLE
OCCUPANT INJURIES.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the trim from the lower right or left
B-pillar. (Refer to 23 - BODY/INTERIOR/B-PILLAR
LOWER TRIM - REMOVAL).
(3) Disconnect the airbag overlay wire harness
connector for the right or left side impact sensor from
the sensor connector receptacle (Fig. 47).
(4) Remove the two screws that secure the right or
left side impact sensor to the B-pillar.
(5) Remove the side impact sensor from the B-pil-
lar.
Fig. 46 Side Impact Sensor
1 - SENSOR
2 - CONNECTOR RECEPTACLE
WJRESTRAINTS 8O - 43
SIDE IMPACT SENSOR (Continued)

INSTALLATION
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 SUPPLEMENTALRESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: THE SIDE IMPACT SENSOR ENABLES
THE SYSTEM TO DEPLOY THE SIDE CURTAIN AIR-
BAG. NEVER STRIKE OR DROP THE SIDE IMPACT
SENSOR, AS IT CAN DAMAGE THE IMPACT SEN-
SOR OR AFFECT ITS CALIBRATION. 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 ACCI-
DENTAL, INCOMPLETE, OR IMPROPER SIDE CUR-
TAIN AIRBAG DEPLOYMENT AND POSSIBLE
OCCUPANT INJURIES.
(1) Position the right or left side impact sensor
onto the B-pillar (Fig. 47).
(2) Install and tighten the two screws that secure
the right or left side impact sensor to the B-pillar.
Tighten the screws to 12 N´m (105 in. lbs.).
(3) Reconnect the airbag overlay wire harness con-
nector for the right or left side impact sensor to the
sensor connector receptacle.
(4) Reinstall the trim onto the lower right or left
B-pillar. (Refer to 23 - BODY/INTERIOR/B-PILLAR
LOWER TRIM - INSTALLATION).
(5) 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).
Fig. 47 Side Impact Sensor Remove/Install
1 - B-PILLAR
2 - SIDE IMPACT SENSOR
3 - SCREW (2)
4 - WIRE HARNESS CONNECTOR
8O - 44 RESTRAINTSWJ
SIDE IMPACT SENSOR (Continued)

(2) Check for continuity between the two terminals
of the hood ajar switch. There should be continuity
with the switch plunger extended, and no continuity
with the switch plunger depressed. If OK, go to Step
3. If not OK, replace the faulty hood ajar switch.
(3) Disconnect the instrument panel wire harness
connector from the Body Control Module (BCM).
Check for continuity between the hood ajar switch
sense circuit of the hood ajar switch and a good
ground. There should be no continuity. If OK, go to
Step 4. If not OK, repair the shorted hood ajar switch
sense circuit between the hood ajar switch and the
BCM.
(4) Check for continuity between the hood ajar
switch sense circuit and the instrument panel wire
harness connector for the BCM. There should be con-
tinuity. If OK, proceed to diagnosis of the Vehicle
Theft Security System (VTSS). (Refer to 8 - ELEC-
TRICAL/VEHICLE THEFT SECURITY - DIAGNO-
SIS AND TESTING). If not OK, repair the open hood
ajar switch sense circuit between the hood ajar
switch and the BCM.
REMOVAL
REMOVAL - HOOD AJAR SWITCH
(1) Open the hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Squeeze the two switch latch tabs together and
pull the switch upward (Fig. 3)
(4) Disconnect the wiring harness connector.
(5) Remove the hood ajar switch from the mount-
ing bracket.
REMOVAL - HOOD AJAR SWITCH BRACKET
(1) Remove the hood ajar switch from the mount-
ing bracket. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY/HOOD AJAR SWITCH -
REMOVAL).
(2) Remove the two nuts that secure the hood ajar
switch bracket to the left inner fender (Fig. 3)
(3) Remove the hood ajar switch bracket from the
studs on the left inner fender.
REMOVAL - HOOD AJAR SWITCH STRIKER
(1) Open the hood.
(2) Using a trim stick or another suitable wide
flat-blade tool, gently raise the hood ajar switch
striker away from the inner hood panel reinforce-
ment, and remove. (Fig. 4).
INSTALLATION
INSTALLATION - HOOD AJAR SWITCH
(1) Position the hood ajar switch into the hole in
the mounting bracket (Fig. 3)
(2) Reconnect the wiring harness connector.
(3) Press the switch downward into the mounting
bracket until the latch tabs lock it into place.
(4) Reconnect the battery negative cable.
(5) Close and latch the hood.
INSTALLATION - HOOD AJAR SWITCH
BRACKET
(1) Position the hood ajar switch bracket onto the
studs on the left inner fender (Fig. 3)
(2) Install and tighten the two nuts. Tighten the
nuts to 11.8 N´m (105 in. lbs.).
(3) Reinstall the hood ajar switch into the mount-
ing bracket. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY/HOOD AJAR SWITCH -
INSTALLATION).
Fig. 4 Hood Ajar Switch Striker
1 - REINFORCEMENT
2 - STRIKER
3 - HOOD
8Q - 10 VEHICLE THEFT SECURITYWJ
HOOD AJAR SWITCH (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)