2002 JEEP LIBERTY gas

sends the proper vehicle speed messages to the
instrument cluster. For further diagnosis of the
speedometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the BCM, the PCM, the
PCI data bus, or the electronic message inputs to the
instrument cluster that control the speedometer, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
TACHOMETER
DESCRIPTION
A tachometer is standard equipment on all instru-
ment clusters. The tachometer is located to the left of
the speedometer in the instrument cluster. The
tachometer consists of a movable gauge needle or
pointer controlled by the instrument cluster circuitry,
and a fixed 255 degree scale on the gauge dial face
that reads left-to-right from 0 to 7 for gasoline
engines, or from 0 to 5 for diesel engines. The text
ªRPM X 1000º imprinted on the cluster overlay
directly below the hub of the tachometer needle iden-
tifies that each number on the tachometer scale is to
be multiplied by 1000 rpm. The gasoline engine
tachometer has a red zone beginning at 5800 RPM,
while the red zone for the diesel engine tachometer
begins at 4300 RPM. The tachometer graphics are
dark blue and red against a beige field, making them
clearly visible within the instrument cluster in day-
light. When illuminated from behind by the panel
lamps dimmer controlled cluster illumination lighting
with the exterior lamps turned On, the dark blue
graphics appear blue and the red graphics appear
red. The orange gauge needle is internally illumi-
nated. Gauge illumination is provided by replaceable
incandescent bulb and bulb holder units located on
the instrument cluster electronic circuit board. The
tachometer is serviced as a unit with the instrument
cluster.
OPERATION
The tachometer gives an indication to the vehicle
operator of the engine speed. This gauge is controlled
by the instrument cluster electronic circuit board
based upon cluster programming and electronic mes-
sages received by the cluster from the Powertrain
Control Module (PCM) over the Programmable Com-
munications Interface (PCI) data bus. The tachome-
ter is an air core magnetic unit that receives battery
current on the instrument cluster electronic circuit
board through the fused ignition switch output (run-
start) circuit whenever the ignition switch is in the
On or Start positions. The cluster is programmed tomove the gauge needle back to the low end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²Engine Speed Message- Each time the cluster
receives an engine speed message from the PCM it
will calculate the correct engine speed reading and
position the gauge needle at that speed position on
the gauge scale. The cluster will receive a new
engine speed message and reposition the gauge
pointer accordingly about every 86 milliseconds. The
gauge needle will continue to be positioned at the
actual engine speed position on the gauge scale until
the ignition switch is turned to the Off position.
²Communication Error- If the cluster fails to
receive an engine speed message, it will hold the
gauge needle at the last indication for about six sec-
onds, or until the ignition switch is turned to the Off
position, whichever occurs first. If a new engine
speed message is not received after about six sec-
onds, the gauge needle will return to the far left
(low) end of the scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept to several calibration points on the gauge scale
in sequence in order to confirm the functionality of
the gauge and the cluster control circuitry.
The PCM continually monitors the crankshaft posi-
tion sensor to determine the engine speed, then
sends the proper engine speed messages to the
instrument cluster. For further diagnosis of the
tachometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the crankshaft position
sensor, the PCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the tachometer, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
TRANS TEMP INDICATOR
DESCRIPTION
A transmission over-temperature indicator is stan-
dard equipment on all instrument clusters, but is
only functional on vehicles equipped with an optional
automatic transmission. The transmission over-tem-
perature indicator is located near the lower edge of
the instrument cluster, between the tachometer and
the speedometer. The transmission over-temperature
indicator consists of a stencil-like cutout of the words
ªTRANS TEMPº in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
KJINSTRUMENT CLUSTER 8J - 33
SPEEDOMETER (Continued)

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,
depending upon the vehicle speed, impact angle,
severity of the impact, and the type of collision.
When the ACM monitors a problem in any of the
dual front airbag system circuits or components,
including the seat belt tensioner, it stores a fault
code or Diagnostic Trouble Code (DTC) in its memory
circuit and sends an electronic message to the EMIC
to turn on the airbag indicator. When the SIACM
monitors a problem in any of the side curtain airbag
system circuits or component, it stores a fault code or
Diagnostic Trouble Code (DTC) in its memory circuit
and sends an electronic message to the ACM, and the
ACM sends an electronic message to the EMIC to
turn on the airbag indicator. Proper testing of the
airbag system components, the Programmable Com-
munication Interface (PCI) data bus, the data bus
message inputs to and outputs from the EMIC, the
SIACM, or the ACM, as well as the retrieval or era-
sure of a DTC from the ACM, SIACM, or EMIC
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
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 passive restraints.
WARNING - RESTRAINT SYSTEM
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 DAIMLERCHRYSLER MOPAR PARTS
CATALOG.WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSOR, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER 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: AN AIRBAG INFLATOR UNIT MAY CON-
TAIN SODIUM AZIDE AND POTASSIUM NITRATE.
THESE MATERIALS ARE POISONOUS AND
EXTREMELY FLAMMABLE. CONTACT WITH ACID,
WATER, OR HEAVY METALS MAY PRODUCE HARM-
FUL AND IRRITATING GASES (SODIUM HYDROXIDE
IS FORMED IN THE PRESENCE OF MOISTURE) OR
COMBUSTIBLE COMPOUNDS. AN AIRBAG INFLA-
TOR UNIT MAY ALSO CONTAIN A GAS CANISTER
PRESSURIZED TO OVER 2500 PSI. DO NOT
ATTEMPT TO DISMANTLE AN AIRBAG UNIT OR
TAMPER WITH ITS INFLATOR. DO NOT PUNCTURE,
INCINERATE, OR BRING INTO CONTACT WITH
ELECTRICITY. DO NOT STORE AT TEMPERATURES
EXCEEDING 93É C (200É F).
WARNING: WHEN HANDLING A SEAT BELT TEN-
SIONER RETRACTOR, PROPER CARE SHOULD BE
EXERCISED TO KEEP FINGERS OUT FROM UNDER
THE RETRACTOR COVER AND AWAY FROM THE
SEAT BELT WEBBING WHERE IT EXITS FROM THE
RETRACTOR COVER.
WARNING: REPLACE ALL RESTRAINT SYSTEM
COMPONENTS ONLY WITH PARTS SPECIFIED IN
THE DAIMLERCHRYSLER MOPAR PARTS CATA-
LOG. SUBSTITUTE PARTS MAY APPEAR INTER-
CHANGEABLE, BUT INTERNAL DIFFERENCES MAY
RESULT IN INFERIOR OCCUPANT PROTECTION.
KJRESTRAINTS 8O - 5
RESTRAINTS (Continued)

Ifnone of the Driver or Passenger Squib 1 or 2
open are active codes, the status of the airbag squibs
is unknown. In this case the airbag should be han-
dled and disposed of as if the squibs were both live.
CLEANUP PROCEDURE
Following a supplemental restraint deployment,
the vehicle interior will contain a powdery residue.
This residue consists primarily of harmless particu-
late by-products of the small pyrotechnic charge that
initiates the propellant used to deploy a supplemen-
tal restraint. However, this residue may also contain
traces of sodium hydroxide powder, a chemical
by-product of the propellant material that is used to
generate the inert gas that inflates the airbag. Since
sodium hydroxide powder can irritate the skin, eyes,
nose, or throat, be sure to wear safety glasses, rubber
gloves, and a long-sleeved shirt during cleanup (Fig.
3).
WARNING: IF YOU EXPERIENCE SKIN IRRITATION
DURING CLEANUP, RUN COOL WATER OVER THE
AFFECTED AREA. ALSO, IF YOU EXPERIENCE IRRITA-
TION OF THE NOSE OR THROAT, EXIT THE VEHICLE
FOR FRESH AIR UNTIL THE IRRITATION CEASES. IF
IRRITATION CONTINUES, SEE A PHYSICIAN.
(1) Begin the cleanup by using a vacuum cleaner
to remove any residual powder from the vehicle inte-
rior. Clean from outside the vehicle and work your
way inside, so that you avoid kneeling or sitting on a
non-cleaned area.
(2) Be certain to vacuum the heater and air condi-
tioning outlets as well (Fig. 4). Run the heater and
air conditioner blower on the lowest speed setting
and vacuum any powder expelled from the outlets.
CAUTION: Deployed front airbags having two initiators
(squibs) in the airbag inflator may or may not have livepyrotechnic material within the inflator. Do not dispose
of these airbags unless you are sure of complete
deployment. Refer to AIRBAG SQUIB STATUS . Refer
to the Hazardous Substance Control System for
proper disposal procedures. Dispose of all non-de-
ployed and deployed airbags in a manner consistent
with state, provincial, local, and federal regulations.
(3) Next, remove the deployed supplemental
restraints from the vehicle. Refer to the appropriate
service removal procedures.
(4) You may need to vacuum the interior of the
vehicle a second time to recover all of the powder.
STANDARD PROCEDURE - VERIFICATION TEST
The following procedure should be performed using
a DRBIIItscan tool to verify proper supplemental
restraint system operation following the service or
replacement of any supplemental restraint system
component.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER 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.
Fig. 3 Wear Safety Glasses and Rubber Gloves -
Typical
Fig. 4 Vacuum Heater and A/C Outlets - Typical
8O - 8 RESTRAINTSKJ
RESTRAINTS (Continued)

The resistive membrane-type horn switch is
secured with heat stakes to the inside surface of the
driver airbag trim cover, between the trim cover and
the folded airbag cushion. The horn switch ground
pigtail wire has a female spade terminal connector
that receives a path to ground through a male spade
terminal that is integral to the driver airbag housing
stamping and is located near the upper right corner
on the back of the housing (Fig. 15). The horn switch
feed pigtail wire has a white, molded plastic insula-
tor that is secured by an integral retainer to a
mounting hole located near the lower left corner on
the back of the housing, and is connected to the vehi-
cle electrical system through a take out and connec-
tor of the steering wheel wire harness.
The airbag 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. A 67 centimeter (26.5
inch) diameter, radial deploying fabric 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 initia-
tors to the vehicle electrical system through two yel-
low-jacketed, two-wire pigtail harnesses of the
clockspring. The driver airbag and horn switch unit
cannot be repaired, and must be replaced if deployed
or in any way damaged.OPERATION
The multistage driver airbag is deployed by electri-
cal signals generated by the Airbag Control Module
(ACM) through the driver airbag squib 1 and squib 2
circuits to the two initiators in the airbag 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 three delay intervals between the
electrical signals provided to the two initiators. The
longer the delay between these signals, the less force-
fully the airbag will deploy. When the ACM sends the
proper electrical signals to each initiator, the electri-
cal energy generates enough heat to initiate a small
pyrotechnic charge which, in turn ignites chemical
pellets within the inflator. Once ignited, these chem-
ical pellets burn rapidly and produce a large quantity
of nitrogen gas. The inflator is sealed to the back of
the airbag housing and a diffuser in the inflator
directs all of the nitrogen gas into the airbag cush-
ion, causing the cushion to inflate. As the cushion
inflates, the driver airbag trim cover will split at pre-
determined breakout lines, then fold back out of the
way along with the horn switch unit. Following an
airbag deployment, the airbag cushion quickly
deflates by venting the nitrogen gas towards the
instrument panel through vent holes within the fab-
ric used to construct the back (steering wheel side)
panel of the airbag cushion.
Some of the chemicals used to create the nitrogen
gas may be considered hazardous while in their solid
state before they are burned, but they are securely
sealed within the airbag inflator. Typically, both ini-
tiators are used and all potentially hazardous chem-
icals are burned during an airbag deployment event.
However, it is possible for only one initiator to be
used during a deployment due to an airbag system
fault; therefore, it is necessary to always confirm
that both initiators have been used in order to avoid
the improper disposal of potentially live pyrotechnic
or hazardous materials. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - SER-
VICE AFTER A SUPPLEMENTAL RESTRAINT
DEPLOYMENT). The nitrogen gas that is produced
when the chemicals are burned is harmless. How-
ever, a small amount of residue from the burned
chemicals may cause some temporary discomfort if it
contacts the skin, eyes, or breathing passages. If skin
or eye irritation is noted, rinse the affected area with
plenty of cool, clean water. If breathing passages are
irritated, move to another area where there is plenty
of clean, fresh air to breath. If the irritation is not
alleviated by these actions, contact a physician.
Fig. 15 Driver Airbag Housing
1 - HOUSING
2 - HORN SWITCH GROUND WIRE
3 - HORN SWITCH FEED WIRE
4 - INFLATOR
5 - TRIM COVER
8O - 18 RESTRAINTSKJ
DRIVER AIRBAG (Continued)

FRONT IMPACT SENSOR
DESCRIPTION
Two front impact sensors are used on this model,
one each for the left and right sides of the vehicle
(Fig. 17). These sensors are mounted remotely from
the impact sensor that is internal to the Airbag Con-
trol Module (ACM). Each front sensor is secured with
two screws to the backs of the right and left vertical
members of the radiator support within the engine
compartment. The sensor housing has an integral
connector receptacle and two integral mounting
points each with a metal sleeve to provide crush pro-
tection.
The right and left front impact sensors are identi-
cal in construction and calibration with two excep-
tions:
²On models equipped with an optional 2.4L gaso-
line engine, the left front impact sensor includes a
shim that moves the sensor three millimeters toward
the rear of the vehicle on the left vertical member of
the radiator support for additional clearance that is
required for that application.
²On models equipped with an optional diesel
engine, the left front impact sensor includes a
stamped metal mounting bracket that rotates theconnector receptacle end of the sensor toward the
outboard side of the vehicle for additional clearance
that is required for that application.
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
front impact sensors are each connected to the vehi-
cle electrical system through a dedicated take out
and connector of the headlamp and dash wire har-
ness.
The impact sensors cannot be repaired or adjusted
and, if damaged or faulty, they must be replaced. The
mounting bracket for the left front impact sensor on
models with a diesel engine is serviced as a unit with
that sensor.
OPERATION
The front impact sensors are electronic accelerom-
eters that sense the rate of vehicle deceleration,
which provides verification of the direction and sever-
ity of an impact. Each sensor also contains an elec-
tronic communication chip that allows the unit to
communicate the sensor status as well as sensor
fault information to the microprocessor in the Airbag
Control Module (ACM). The ACM microprocessor con-
tinuously monitors all of the front 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
front impact sensors and the ACM may be diagnosed
and tested using conventional diagnostic tools and pro-
cedures. However, conventional diagnostic methods will
not prove conclusive in the diagnosis of the ACM or the
impact sensors. The most reliable, efficient, and accu-
rate means to diagnose the impact sensors, the ACM,
and the electronic message communication between the
sensors and the ACM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic informa-
tion.
Fig. 17 Front Impact Sensor
1 - SENSOR
2 - CONNECTOR RECEPTACLE
KJRESTRAINTS 8O - 21

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 converts the electrical energy into
chemical energy. This chemical energy opens up a
burst disk to allow the inert gas to flow into the air-
bag cushion. The inflator is 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 cushion inflates, the passenger air-
bag door will split at predetermined tear seam lines
on the inside surface of the door and the door will
pivot downwards out of the way. Following a passen-
ger 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 cushion.
Typically, both initiators are used during an airbag
deployment event. However, it is possible for only one
initiator to be used during a deployment due to an
airbag system fault; therefore, it is necessary to
always confirm that both initiators have been used in
order to avoid the improper disposal of potentially
live pyrotechnic materials. (Refer to 8 - ELECTRI-
CAL/RESTRAINTS - STANDARD PROCEDURE -
SERVICE AFTER A SUPPLEMENTAL RESTRAINT
DEPLOYMENT).
REMOVAL
The following procedure is for replacement of a
faulty or damaged passenger airbag. If the passenger
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 PROCEDURE - 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, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER 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.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the passenger airbag door from the
instrument panel. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/PASSENGER AIRBAG DOOR - REMOV-
AL).
(3) Remove the two screws on each side of the pas-
senger airbag that secure the passenger airbag to the
metal brackets on the instrument panel support
structure (Fig. 25).
(4) Disengage the passenger airbag wire harness
connector from the retainer securing the connector to
the metal bracket on the instrument panel support
structure above the airbag by sliding both halves of
the connector to the left.
(5) Disconnect the passenger airbag pigtail wire
connector from the instrument panel wire harness
connector for the airbag. To disconnect the connector:
(a) Slide the red Connector Position Assurance
(CPA) lock on the top of the connector toward the
side of the connector.
(b) Depress the connector latch tab and pull the
two halves of the connector straight away from
each other.
Fig. 25 Passenger Airbag Remove/Install
1 - PASSENGER AIRBAG
2 - WIRE HARNESS CONNECTOR
3 - SCREW (4)
4 - GLOVE BOX LATCH STRIKER
8O - 28 RESTRAINTSKJ
PASSENGER AIRBAG (Continued)

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
plastic slide with a small, enclosed permanent mag-
net 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
into close proximity of the Hall Effect Integrated Cir-
cuit (IC) chip within the buckle, which induces a cur-
rent 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 and permanent magnet move upward
and away from the IC, 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
seat wire harness. The ACM also monitors the condi-
tion of the seat belt switch circuits through circuit
resistance created by the diagnostic resistor. The
ACM will illuminate the airbag indicator in the
EMIC and 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 appro-
priate diagnostic information.
SEAT BELT TENSIONER
DESCRIPTION
A driver side seat belt tensioner supplements the
driver airbag system for all versions of this model
(Fig. 34). The seat belt tensioner is integral to the
driver side front seat belt and retractor unit, which is
secured to the B-pillar on the left side of the vehicle.
The retractor is concealed beneath the molded plastic
B-pillar trim. The seat belt tensioner consists prima-
rily of a molded plastic tensioner housing, a tubularmetal piston housing, a piston, a short rack gear, a
set of pinion gears, a pyrotechnically activated gas
generator, and a short pigtail wire. All of these com-
ponents are located on one side of the retractor spool
on the outside of the retractor housing. The seat belt
tensioner is controlled by the Airbag Control Module
(ACM) and is connected to the vehicle electrical sys-
tem through a dedicated take out of the body wire
harness by a keyed and latching molded plastic con-
nector insulator to ensure a secure connection.
The seat belt tensioner cannot be repaired and, if
faulty or damaged, the entire driver side front seat
belt and retractor unit must be replaced. The seat
belt tensioner is not intended for reuse and must be
replaced following a deployment. A locked retractor
that will not allow the seat belt webbing to be
retracted or extracted is a sure indication that the
seat belt tensioner has been deployed and requires
replacement. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/FRONT SEAT BELT & RETRACTOR -
REMOVAL).
OPERATION
The seat belt tensioner is deployed by a signal gen-
erated by the Airbag Control Module (ACM) through
the driver seat belt tensioner line 1 and line 2 (or
squib) circuits. When the ACM sends the proper elec-
trical signal to the tensioner, the electrical energy
generates enough heat to initiate a small pyrotechnic
gas generator. The gas generator is installed in one
end of the tubular metal piston housing, which con-
tains a piston and a small rack gear. As the gas
expands, it pushes the piston and the rack gear
Fig. 34 Seat Belt Tensioner
1 - RETRACTOR
2 - TENSIONER HOUSING
3 - PISTON HOUSING
4 - PIGTAIL WIRE
5 - GAS GENERATOR
8O - 36 RESTRAINTSKJ
SEAT BELT SWITCH (Continued)

screws. A two-wire pigtail harness is routed forward
from the airbag inflator through a trough along the
top of the plastic airbag channel on the roof rail and
down the B-pillar, where it is retained by three rout-
ing clips. The pigtail harness is connected to a take
out and connector of the body wire harness on the
B-pillar, which connects to the respective right or left
Side Impact Airbag Control Module (SIACM) on the
sill panel at the base of the B-pillar.
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 left or right Side
Impact Airbag Control Module (SIACM) to which it is
connected through left or right curtain airbag line 1 and
line 2 (or squib) circuits. The hybrid-type inflatorassembly for each airbag contains a small canister of
highly compressed helium gas. When the SIACM sends
the proper electrical signal to the airbag inflator, the
electrical energy creates enough heat to ignite chemical
pellets within the inflator. Once ignited, these chemicals
burn rapidly and produce the pressure necessary to rup-
ture a containment disk in the helium gas canister. The
inflator and helium gas canister are sealed and con-
nected to a tubular manifold so that all of the released
gas is directed into the folded 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 tether keeps the front por-
tion of the 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 helium gas through the loose weave of
the cushion fabric, and the deflated cushion hangs
down loosely from the roof rail.
Fig. 37 Side Curtain Airbag
1 - INFLATOR
2 - MANIFOLD
3 - CHANNEL
4 - TETHER5 - PIGTAIL WIRE RETAINER (3)
6 - PUSH-IN FASTENER (4)
7 - BRACKET (3)
KJRESTRAINTS 8O - 39
SIDE CURTAIN AIRBAG (Continued)