2003 JEEP GRAND CHEROKEE instrument panel description

wired between a body ground, the Body Control Mod-
ule (BCM) and the rear wiper motor module through
the liftgate and body wire harnesses.
The liftgate flip-up glass ajar switch cannot be
adjusted or repaired and, if faulty or damaged, the
liftgate flip-up glass latch unit must be replaced.
(Refer to 23 - BODY/DECKLID/HATCH/LIFTGATE/
TAILGATE/FLIP-UP GLASS LATCH - REMOVAL)
for the service procedures. For complete circuit dia-
grams, refer to the appropriate wiring information.
DESCRIPTION - LIFTGATE AJAR SWITCH
The two liftgate ajar switches are integral to the
two liftgate latch mechanisms. The two liftgate ajar
switches are actuated by the liftgate latch mecha-
nisms, and are hard wired with each other between a
body ground and the Body Control Module (BCM)
through the liftgate and body wire harnesses.
The liftgate ajar switches cannot be adjusted or
repaired and, if faulty or damaged, the liftgate latch
unit must be replaced. (Refer to 23 - BODY/DECK-
LID/HATCH/LIFTGATE/TAILGATE/LATCH -
REMOVAL) for the service procedures. For complete
circuit diagrams, refer to the appropriate wiring
information.
OPERATION
OPERATION - DOOR AJAR SWITCH
The front door ajar switches close a path to ground
for the DDM or the PDM when a front door is
opened, and opens the ground path when a front door
is closed. The rear door ajar switches close a path to
ground for the BCM when a rear door is opened, and
opens the ground path when a rear door is closed.
The DDM, PDM, or BCM read the switch status then
send the proper switch status messages to other
modules over the Programmable Communications
Interface (PCI) data bus network. The door ajar
switch status message is used by the BCM as an
input for Vehicle Theft Security System (VTSS) oper-
ation.
OPERATION - FLIP UP GLASS AJAR SWITCH
The liftgate flip-up glass ajar switch can close a
path to ground for the BCM and the rear wiper
motor module when the liftgate flip-up glass is
opened, and opens the ground path when the liftgate
flip-up glass is closed. The rear wiper motor module
uses the liftgate flip-up glass ajar switch input to
control the rear wiper operation, and will park the
rear wiper blade if this input indicates that the lift-
gate flip-up glass is ajar. The BCM reads the switch
status then sends the proper switch status message
to other modules over the Programmable Communi-cations Interface (PCI) data bus network. The liftgate
flip-up glass ajar switch status message is used by
the BCM as an input for Vehicle Theft Security Sys-
tem (VTSS) operation.
OPERATION - LIFTGATE AJAR SWITCH
Each of the liftgate ajar switches can close a path
to ground for the BCM when the liftgate is opened,
and opens the ground path when the liftgate is
closed. The BCM reads the switch status then sends
the proper switch status message to other modules
over the Programmable Communications Interface
(PCI) data bus network. The liftgate ajar switch sta-
tus message is used by the BCM as an input for
Vehicle Theft Security System (VTSS) operation.
DIAGNOSIS AND TESTING - DOOR AJAR
SWITCH
The following diagnosis and testing is only
for the chime functions. For interior lamp diag-
nosis, refer to the appropriate wiring informa-
tion.The driver door ajar switch is hard wired to the
Driver Door Module (DDM). The DDM communicates
the switch status to the other modules in the vehicle
on the Programmable Communications Interface
(PCI) data bus network. The following test will diag-
nose a faulty driver door ajar switch and circuits. For
complete circuit diagrams, refer to the appropriate
wiring information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Check that the interior lighting switch on the
control stalk of the left multi-function switch is not
in the dome lamp disable position. Open the driver
side front door and note whether the interior lamps
light. They should light. If OK, refer to Key-In Igni-
tion Switch in the Diagnosis and Testing section of
this group for further diagnosis of the chime warning
system. If not OK, go to Step 2.
(2) Disconnect and isolate the battery negative
cable. Remove the trim panel from the driver front
door and disconnect the 4-way door wire harness con-
nector from the front door latch connector. Check for
continuity between the ground circuit of the 4-way
door wire harness connector and a good ground.
There should be continuity. If OK, go to Step 3. If not
OK, repair the ground circuit.
8L - 30 LAMPS/LIGHTING - INTERIORWJ
DOOR AJAR SWITCH (Continued)

²Passenger Airbag- The passenger airbag is
located on the instrument panel, beneath the instru-
ment panel top pad and above the glove box on the
passenger side of the vehicle.
²Passenger Knee Blocker- The passenger knee
blocker is a structural reinforcement that is integral
to and concealed within the glove box door.
²Side Impact Sensor- Two side impact sensors
are used on vehicles with the optional side curtain
airbags, one left side and one right side. One sensor
is located behind the B-pillar trim near the base of
each B-pillar.
²Side Curtain Airbag- In vehicles equipped
with this option, a side curtain airbag is located on
each inside roof side rail above the headliner, and
extends from the A-pillar to just beyond the C-pillar.
The ACM and the EMIC each contain a central
processing unit and programming that allow them to
communicate with each other using the Programma-
ble Communication Interface (PCI) data bus network.
This method of communication is used by the ACM
for control of the airbag indicator on all models
equipped with dual front airbags. (Refer to 8 - ELEC-
TRICAL/ELECTRONIC CONTROL MODULES/
COMMUNICATION - DESCRIPTION).
Hard wired circuitry connects the supplemental
restraint system components to each other through
the electrical system of the vehicle. These hard wired
circuits are integral to several wire harnesses, which
are routed throughout the vehicle and retained by
many different methods. These circuits may be con-
nected to each other, to the vehicle electrical system,
and to the supplemental restraint system compo-
nents through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
OPERATION
ACTIVE RESTRAINTS
The primary passenger restraints in this or any
other vehicle are the standard equipment factory-in-
stalled seat belts. Seat belts are referred to as an
active restraint because the vehicle occupants are
required to physically fasten and properly adjust
these restraints in order to benefit from them. See
the owner's manual in the vehicle glove box for more
information on the features, use and operation of all
of the factory-installed active restraints.PASSIVE RESTRAINTS
The passive restraints system is referred to as a
supplemental restraint system because they were
designed and are intended to enhance the protection
for the vehicle occupants of the vehicleonlywhen
used in conjunction with the seat belts. They are
referred to as passive systems because the vehicle
occupants are not required to do anything to make
them operate; however, the vehicle occupants must
be wearing their seat belts in order to obtain the
maximum safety benefit from the factory-installed
supplemental restraint systems.
The supplemental restraint system electrical cir-
cuits are continuously monitored and controlled by a
microprocessor and software contained within the
Airbag Control Module (ACM). An airbag indicator in
the ElectroMechanical Instrument Cluster (EMIC)
illuminates for about seven seconds as a bulb test
each time the ignition switch is turned to the On or
Start positions. Following the bulb test, the airbag
indicator is turned on or off by the ACM to indicate
the status of the supplemental restraint system. If
the airbag indicator comes on at any time other than
during the bulb test, it indicates that there is a prob-
lem in the supplemental restraint system electrical
circuits. Such a problem may cause airbags not to
deploy when required, or to deploy when not
required.
Deployment of the supplemental restraints
depends upon the angle and severity of an impact.
Deployment is not based upon vehicle speed; rather,
deployment is based upon the rate of deceleration as
measured by the forces of gravity (G force) upon the
impact sensors. When an impact is severe enough,
the microprocessor in the ACM signals the inflator
unit of the airbag module to deploy the airbag. Dur-
ing a frontal vehicle impact, the knee blockers work
in concert with properly fastened and adjusted seat
belts to restrain both the driver and the front seat
passenger in the proper position for an airbag deploy-
ment. The knee blockers also absorb and distribute
the crash energy from the driver and the front seat
passenger to the structure of the instrument panel.
Typically, the vehicle occupants recall more about
the events preceding and following a collision than
they have of an airbag deployment itself. This is
because the airbag deployment and deflation occur so
rapidly. In a typical 48 kilometer-per-hour (30 mile-
per-hour) barrier impact, from the moment of impact
until the airbags are fully inflated takes about 40
milliseconds. Within one to two seconds from the
moment of impact, the airbags are almost entirely
deflated. The times cited for these events are approx-
imations, which apply only to a barrier impact at the
given speed. Actual times will vary somewhat,
8O - 4 RESTRAINTSWJ
RESTRAINTS (Continued)

(4) Check to be certain that nobody is in the vehi-
cle, then reconnect the battery negative cable.
(5) Using the DRBIIIt, read and record the active
(current) Diagnostic Trouble Code (DTC) data.
(6) Next, use the DRBIIItto read and record any
stored (historical) DTC data.
(7) If any DTC is found in Step 5 or Step 6, refer
to the appropriate diagnostic information.
(8) Use the DRBIIItto erase the stored DTC data.
If any problems remain, the stored DTC data will not
erase. Refer to the appropriate diagnostic informa-
tion to diagnose any stored DTC that will not erase.
If the stored DTC information is successfully erased,
go to Step 9.
(9) Turn the ignition switch to the Off position for
about fifteen seconds, and then back to the On posi-
tion. Observe the airbag indicator in the instrument
cluster. It should light for six to eight seconds, and
then go out. This indicates that the supplemental
restraint system is functioning normally and that the
repairs are complete. If the airbag indicator fails to
light, or lights and stays on, there is still an active
supplemental restraint system fault or malfunction.
Refer to the appropriate diagnostic information to
diagnose the problem.
AIRBAG CONTROL MODULE
DESCRIPTION
The Airbag Control Module (ACM) is also some-
times referred to as the Occupant Restraint Control-
ler (ORC) (Fig. 6). The ACM is concealed underneath
the center floor console, where it is secured by four
screws to a stamped steel mounting bracket welded
onto the top of the floor panel transmission tunnel
just forward of the park brake mechanism in the pas-
senger compartment of the vehicle.
Concealed within a hollow in the center of the die
cast aluminum ACM housing is the electronic cir-
cuitry of the ACM which includes a microprocessor,
an electronic impact sensor, an electronic safing sen-
sor, and an energy storage capacitor. A stamped
metal cover plate is secured to the bottom of the
ACM housing with four screws to enclose and protect
the internal electronic circuitry and components. A
printed label on the top of the ACM housing provides
a visual verification of the proper orientation of the
unit, and should always be pointed toward the front
of the vehicle.
Two molded plastic electrical connector receptacles
exit the forward side of the ACM housing. These two
receptacles connect the ACM to the vehicle electrical
system through a dedicated take out and connector of
the instrument panel wire harness, and a dedicated
take out and connector of the airbag overlay wire
harness. For vehicles equipped with the optional side
curtain airbags, both ACM connector receptacles are
black in color and the ACM contains a second bi-di-
rectional safing sensor for the side airbags. For vehi-
cles not equipped with the optional side curtain
airbags, the ACM connector receptacles are both
gray.
The impact sensor and safing sensor internal to
the ACM are calibrated for the specific vehicle, and
are only serviced as a unit with the ACM. The ACM
cannot be repaired or adjusted and, if damaged or
faulty, it must be replaced.
OPERATION
The microprocessor in the Airbag Control Module
(ACM) contains the supplemental restraint system
logic circuits and controls all of the supplemental
restraint system components. The ACM uses
On-Board Diagnostics (OBD) and can communicate
with other electronic modules in the vehicle as well
as with the DRBIIItscan tool using the Programma-
ble Communications Interface (PCI) data bus net-
work. This method of communication is used for
control of the airbag indicator in the ElectroMechani-
cal Instrument Cluster (EMIC) and for supplemental
restraint system diagnosis and testing through the
16-way data link connector located on the driver side
lower edge of the instrument panel. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/COMMUNICATION - OPERATION).
Fig. 6 Airbag Control Module
1 - AIRBAG CONTROL MODULE
2 - ORIENTATION ARROW
3 - LABEL
4 - MOUNTING HOLES (4)
5 - CONNECTOR RECEPTACLE (2)
WJRESTRAINTS 8O - 9
RESTRAINTS (Continued)

INSTALLATION
The following service procedure applies to vehicles
manufactured for sale in North America, which have
removable child seat tether anchor brackets that are
located on the inner liftgate opening header. Vehicles
manufactured for sale in Rest-Of-World (ROW) mar-
kets have child tether anchors that are integral to,
and are only serviced with the rear seat back panels.
(1) Position the child tether anchor bracket onto
the inner liftgate opening header (Fig. 12).
(2) Install and tighten the screw that secures the
child tether anchor bracket to the inner liftgate open-
ing header. Tighten the screw to 11.8 N´m (105 in.
lbs.).
(3) Reinstall the cover into the child tether anchor
bezel in the headliner near the liftgate opening
header.
CLOCKSPRING
DESCRIPTION
The clockspring assembly is secured with two
screws to the multi-function switch mounting hous-
ing near the top of the steering column behind the
steering wheel (Fig. 13). The clockspring consists of a
flat, round molded plastic case with a stubby tail
that hangs below the steering column and contains
two connector receptacles that face toward the
instrument panel (Fig. 14). Within the plastic hous-ing is a spool-like molded plastic rotor with a large
exposed hub. The upper surface of the rotor hub has
a large center hole, two large flats, an index hole,
two short pigtail wires with connectors, and two con-
nector receptacles that face toward the steering
wheel.
The lower surface of the rotor hub has three pins,
two round and one oblong. These pins index the
clockspring to the turn signal cancel cam unit in the
multi-function switch mounting housing. Within the
plastic case and wound around the rotor spool is a
long ribbon-like tape that consists of several thin cop-
per wire leads sandwiched between two thin plastic
membranes. The outer end of the tape terminates at
the connector receptacles that face the instrument
panel, while the inner end of the tape terminates at
the pigtail wires and connector receptacles on the
hub of the clockspring rotor that face the steering
wheel.
Service replacement clocksprings are shipped pre-
centered and with a molded plastic locking pin
installed. The locking pin secures the centered clock-
spring rotor to the clockspring case during shipment
and handling, but must be removed from the clock-
spring after it and the multi-function switch mount-
ing housing are installed on the steering column.
(Refer to 8 - ELECTRICAL/RESTRAINTS/CLOCK-
SPRING - STANDARD PROCEDURE - CLOCK-
SPRING CENTERING).
The clockspring cannot be repaired. If the clock-
spring is faulty, damaged, or if the driver airbag has
been deployed, the clockspring must be replaced.
Fig. 13 Clockspring (Upper View)
1 - MOUNTING EAR (2)
2 - LOCKING PIN
3 - UPPER CONNECTOR RECEPTACLE (2)
4 - LABEL
5 - OBLONG PIN
6 - ALIGNMENT ARROWS
7 - CASE
8 - PIGTAIL WIRE (2)
Fig. 14 Clockspring (Lower View)
1 - LOCKING PIN
2 - CASE
3 - OBLONG PIN
4 - ROUND PIN (2)
5 - LOWER CONNECTOR RECEPTACLE (2)
6 - ROTOR
8O - 14 RESTRAINTSWJ
CHILD TETHER ANCHOR (Continued)

(3) Align and seat the one pin and the two mount-
ing ears on the clockspring case to their respective
holes in the multi-function switch mounting housing.
(4) Install and tighten the two clockspring mount-
ing screws. Tighten the screws to 2.5 N´m (22 in.
lbs.).
(5) Reconnect the two instrument panel wire har-
ness connectors for the clockspring to the two connec-
tor receptacles below the steering column on the back
of the clockspring case.
(6) Position the lower tilting steering column
shroud onto the steering column (Fig. 16).
(7) Install and tighten the screw that secures the
lower tilting steering column shroud to the multi-
function switch mounting housing. Tighten the screw
to 2 N´m (17 in. lbs.).
(8) Position the upper tilting column shroud onto
the steering column with the hazard warning switch
button inserted through the hole in the upper surface
of the shroud. Align the upper tilting steering column
shroud to the lower shroud and snap the two shroud
halves together.
(9) Align the snap features on the upper and lower
shrouds and apply hand pressure to snap them
together.
(10) Reinstall the steering wheel onto the steering
column. (Refer to 19 - STEERING/COLUMN/STEER-
ING WHEEL - INSTALLATION).
(11)
Reconnect the steering wheel wire harness con-
nectors to the upper clockspring connector receptacles.
(12) Reinstall the driver airbag onto the steering
wheel. (Refer to 8 - ELECTRICAL/RESTRAINTS/
DRIVER AIRBAG - INSTALLATION).
DRIVER AIRBAG
DESCRIPTION
The injection molded, thermoplastic driver airbag
protective trim cover is the most visible part of the
driver airbag (Fig. 18). The driver airbag is located in
the center of the steering wheel, where it is secured
with two screws to the two horizontal spokes of the
four-spoke steering wheel armature. A stamped, satin
polished emblem with the Jeeptlogo is applied to the
center of the trim cover. Concealed beneath the
driver airbag trim cover are the horn switch, the
folded airbag cushion, the airbag retainer or housing,
the airbag inflator, and the retainers that secure the
inflator to the airbag housing.
The airbag cushion, housing, and inflator are
secured within an integral receptacle molded into the
back of the trim cover. The driver airbag trim cover
has locking blocks molded into the back side of it
that engage a lip formed around the perimeter of the
airbag housing. Two stamped metal retainers then fitover the inflator mounting studs on the back of the
airbag housing and are engaged in slots within the
upper and lower trim cover locking blocks, securely
locking the cover into place.
The resistive membrane-type horn switch is
secured within a plastic tray that is inserted in a
pocket or pouch sewn onto the airbag cushion
retainer strap, between the trim cover and the folded
airbag cushion. The horn switch ground pigtail wire
has an eyelet terminal connector that is captured on
the upper right inflator mounting stud between the
inflator and the upper trim cover retainer. The horn
switch feed pigtail wire has a white, molded plastic
insulator that is secured by an integral retainer to a
mounting hole located in the upper trim cover
retainer near the upper left corner on the back of the
airbag housing, and is connected to the vehicle elec-
trical system through a take out and connector of the
steering wheel wire harness.
The airbag used in this model is a multistage, Next
Generation-type that complies with revised federal air-
bag standards to deploy with less force than those used
in some prior models. A radial deploying fabric airbag
cushion with tethers is used. The airbag inflator is a
dual-initiator, non-azide, pyrotechnic-type unit with
four mounting studs and is secured to the stamped
metal airbag housing using four hex nuts with washers.
Two keyed and color-coded connector receptacles on the
driver airbag inflator connect the two inflator initiators
to the vehicle electrical system through two yellow-
jacketed, two-wire pigtail harnesses of the clockspring.
The driver airbag cannot be repaired, and must be
replaced if deployed or in any way damaged. The driver
airbag trim cover and the horn switch are available
individually, and may be disassembled from the driver
airbag for service replacement.
Fig. 18 Driver Airbag Trim Cover
1 - STEERING WHEEL
2 - TRIM COVER
8O - 18 RESTRAINTSWJ
CLOCKSPRING (Continued)

PASSENGER AIRBAG
DESCRIPTION
The rearward facing surface of the instrument
panel top pad above the glove box is the most visible
part of the passenger airbag (Fig. 31). The passenger
airbag is located above the glove box opening in front
of the front seat passenger seating position within
the instrument panel. The stamped steel passenger
airbag door is secured on the back of the instrument
panel top pad armature between the two passenger
side panel outlets. A stamped metal reinforcement is
secured to the instrument panel top pad armature
near the upper edge of the passenger airbag door
opening, and helps to define a predetermined hinge
line beneath the decorative cover of the top pad. The
instrument panel passenger side bezel is secured to
the airbag door from behind with four screws.
Located behind the passenger airbag door within
the instrument panel is the passenger airbag unit.
The passenger airbag unit used in this model is a
multistage, Next Generation-type that complies with
revised federal airbag standards to deploy with less
force than those used in some prior models. The pas-
senger airbag unit consists of an extruded aluminum
housing, a molded plastic inner airbag cushion dust
cover, the airbag cushion, and the airbag inflator.
The airbag housing contains the airbag inflator,
while the inner dust cover contains the folded airbag
cushion. The dust cover completely encloses the air-
bag cushion and is permanently retained to the hous-
ing. The passenger airbag unit is secured with four
screws to the instrument panel structural duct. Con-cealed beneath the instrument panel top pad are the
passenger airbag door, the folded airbag cushion, the
airbag retainer or housing, and the airbag inflator.
The airbag cushion is constructed of a coated nylon
fabric. The airbag inflator is a dual-initiator, hybrid-
type unit that is secured to and sealed within the air-
bag housing. A short four-wire pigtail harness with a
keyed, yellow connector insulator connects the two
inflator initiators to the vehicle electrical system
through a dedicated take out and connector of the
instrument panel wire harness.
The passenger airbag cannot be repaired, and must
be replaced if deployed, faulty, or in any way dam-
aged. The passenger airbag cannot be repaired, and
must be replaced if faulty or in any way damaged.
The passenger airbag door is serviced only as a unit
with the instrument panel top pad. Following a pas-
senger airbag deployment, the passenger airbag and
the instrument panel top pad must be replaced. If
inspection reveals that the passenger airbag mount-
ing points on the instrument panel structural duct
have been cracked or damaged, the instrument panel
structural duct assembly must also be replaced.
OPERATION
The multistage passenger airbag is deployed by
electrical signals generated by the Airbag Control
Module (ACM) through the passenger airbag squib 1
and squib 2 circuits to the two initiators in the air-
bag inflator. By using two initiators, the airbag can
be deployed at multiple levels of force. The force level
is controlled by the ACM to suit the monitored
impact conditions by providing one of four delay
intervals between the electrical signals provided to
the two initiators. The longer the delay between
these signals, the less forcefully the airbag will
deploy.
The hybrid-type inflator assembly includes a small
canister of highly compressed gas. When the ACM
sends the proper electrical signal to the airbag infla-
tor, the initiator generates enough heat to ignite
chemical pellets within the inflator. Once ignited,
these chemical pellets burn rapidly and produce the
pressure necessary to rupture a containment disk in
the pressurized gas canister. The inflator and gas
canister are sealed to the airbag cushion so that all
of the released inert gas is directed into the airbag
cushion, causing the cushion to inflate. As the cush-
ion inflates, the passenger airbag door will bend back
the instrument panel top pad at the predetermined
hinge line, then fold back over the top of the instru-
ment panel and out of the way. Following an airbag
deployment, the airbag cushion quickly deflates by
venting the inert gas through vent holes within the
fabric used to construct the sides of the airbag cush-
ion.
Fig. 31 Passenger Airbag Door
1 - BEZEL
2-TOPPAD
3 - PASSENGER AIRBAG DOOR
4 - GLOVE BOX DOOR
8O - 30 RESTRAINTSWJ

NOTE: Vehicles equipped with a three-point center
seat belt have the center seat belt lower anchor
secured to the right buckle anchor plate with a
screw instead of the center lap belt. (Refer to 8 -
ELECTRICAL/RESTRAINTS/REAR CENTER SEAT
BELT & RETRACTOR - INSTALLATION).
(3) Fold the rear seat cushion back into the seat-
ing position.
SEAT BELT SWITCH
DESCRIPTION
The seat belt switch for this model is actually a
Hall Effect-type sensor. This sensor consists of a
fixed-position, Hall Effect Integrated Circuit (IC) chip
and a small permanent magnet that are integral to
each front seat belt buckle. The front seat belt buck-
les are each located on a stamped steel stanchion
within a molded plastic scabbard and secured with a
screw to the floor panel transmission tunnel on the
inboard side of each front seat cushion (Fig. 40). Theseat belt switches are connected to the vehicle elec-
trical system through a two-lead pigtail wire and
connector on the seat belt buckle-half, which is con-
nected to a wire harness connector and take out of
the body wire harness on vehicles with manual seat
adjusters, or to a connector and take out of the power
seat wire harness on vehicles with power seat adjust-
ers. A radio noise suppression capacitor is connected
in parallel with the IC where the two pigtail wire
leads connect to the IC pins.
The seat belt switch cannot be adjusted or repaired
and, if faulty or damaged, the entire seat belt buckle-
half unit must be replaced.
OPERATION
The seat belt switches are designed to provide a
status signal to the seat belt switch sense inputs of
the Airbag Control Module (ACM) indicating whether
the front seat belts are fastened. The ACM uses the
seat belt switch inputs as a factor in determining
what level of force with which it should deploy the
multistage driver and passenger airbags. In addition,
the ACM sends electronic messages to the ElectroMe-
chanical Instrument Cluster (EMIC) to control the
seat belt indicator based upon the status of the
driver side front seat belt switch. A spring-loaded
slide with a small window-like opening is integral to
the buckle latch mechanism. When a seat belt tip-
half is inserted and latched into the seat belt buckle,
the slide is pushed downward and the window of the
slide exposes the Hall Effect Integrated Circuit (IC)
chip within the buckle to the field of the permanent
magnet, which induces a current within the chip.
The chip provides this induced current as an output
to the ACM, which monitors the current to determine
the status of the front seat belts. When the seat belt
is unbuckled, the spring-loaded slide moves upward
and shields the IC from the field of the permanent
magnet, causing the output current from the seat
belt switch to be reduced.
The seat belt switch receives a supply current from
the ACM, and the ACM senses the status of the front
seat belts through its pigtail wire connection to the
airbag overlay wire harness. The ACM monitors the
condition of the seat belt switch circuits and will illu-
minate the airbag indicator in the EMIC then store a
Diagnostic Trouble Code (DTC) for any fault that is
detected in either seat belt switch circuit. For proper
diagnosis of the seat belt switches, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
Fig. 40 Front Seat Belt Buckle
1 - SEAT BELT BUCKLE
2 - SEAT BELT SWITCH PIGTAIL WIRE
3 - SCREW
WJRESTRAINTS 8O - 37
REAR SEAT BELT BUCKLE (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)