Driver Side Airbag Module Description And Operation - Jeep 200 Cherokee Service Manual

8M - 2 PASSIVE RESTRAINT SYSTEMS
DESCRIPTION AND OPERATION (Continued)
Module (ACM). The ACM also contains an impact
sensor and a safing sensor, which are monitored by
the ACM to determine when an impact occurs that is
severe enough to require airbag system protection.
When a frontal impact is severe enough, the ACM
signals the inflator units of both airbag modules to
deploy the airbags.
An airbag indicator lamp in the instrument cluster
lights 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 indica-
tor lamp is turned on or off by the ACM to indicate
the status of the airbag system. If the airbag indica-
tor lamp comes on at any time other than during the
bulb test, it indicates that there is a problem in the
airbag system circuits. Such a problem may cause
the airbags not to deploy when required, or to deploy
when not required.
The driver side airbag module includes an inflat-
able airbag and an inflator unit behind a trim cover
in the hub area of the steering wheel. The passenger
side airbag module includes a second inflatable air-
bag and an inflator unit behind an airbag door in the
instrument panel above the glove box.
During a frontal vehicle impact, the knee blockers
work in concert with properly adjusted seat belts to
restrain the driver and front seat passenger in the
proper position for an airbag deployment. The knee
blockers also work to absorb and distribute the crash
energy from the driver and front seat passenger to
the structure of the instrument panel. The driver
side knee blocker is a stamped metal reinforcement
located behind the instrument panel steering column
opening cover. The passenger side knee blocker is
integral to the glove box door.
Following are general descriptions of the major
components in the airbag system.
WARNING:
• THE AIRBAG SYSTEM IS A SENSITIVE, COM-
PLEX ELECTROMECHANICAL
ATTEMPTING TO DIAGNOSE OR SERVICE ANY AIR-
BAG SYSTEM OR RELATED STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENTS YOU MUST FIRST DISCONNECT
AND ISOLATE THE BATTERY NEGATIVE (GROUND)
CABLE. THEN WAIT TWO MINUTES FOR THE SYS-
TEM CAPACITOR TO DISCHARGE BEFORE FUR-
THER SYSTEM SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE
TO DO THIS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
• THE DRIVER SIDE AIRBAG MODULE INFLATOR
ASSEMBLY CONTAINS SODIUM AZIDE AND POTAS-
SIUM NITRATE. THESE MATERIALS ARE POISON-
OUS AND EXTREMELY FLAMMABLE. CONTACT
WITH ACID, WATER, OR HEAVY METALS MAY PRO-
DUCE HARMFUL AND IRRITATING GASES (SODIUM
HYDROXIDE IS FORMED IN THE PRESENCE OF
MOISTURE) OR COMBUSTIBLE COMPOUNDS. THE
PASSENGER AIRBAG MODULE CONTAINS ARGON
GAS PRESSURIZED TO OVER 2500 PSI. DO NOT
ATTEMPT TO DISMANTLE AN AIRBAG MODULE OR
TAMPER WITH ITS INFLATOR. DO NOT PUNCTURE,
INCINERATE, OR BRING INTO CONTACT WITH
ELECTRICITY. DO NOT STORE AT TEMPERATURES
EXCEEDING 93° C (200° F).
ONLY WITH PARTS SPECIFIED IN THE CHRYSLER
MOPAR PARTS CATALOG. SUBSTITUTE PARTS
MAY APPEAR INTERCHANGEABLE, BUT INTERNAL
DIFFERENCES MAY RESULT IN INFERIOR OCCU-
PANT PROTECTION.
INALLY USED FOR THE AIRBAG SYSTEM COMPO-
NENTS
SPECIFICALLY DESIGNED FOR THE AIRBAG SYS-
TEM. THEY MUST NEVER BE REPLACED WITH ANY
SUBSTITUTES. ANY TIME A NEW FASTENER IS
NEEDED, REPLACE IT WITH THE CORRECT FAS-
TENERS PROVIDED IN THE SERVICE PACKAGE OR
SPECIFIED IN THE CHRYSLER MOPAR PARTS CAT-
ALOG.
MODULE ATTACHED, NEVER PLACE THE COLUMN
ON THE FLOOR OR ANY OTHER SURFACE WITH
THE STEERING WHEEL OR AIRBAG MODULE FACE
DOWN.
DRIVER SIDE AIRBAG MODULE
DESCRIPTION
is the most visible part of the driver side airbag sys-
tem. The driver side airbag module is mounted
UNIT. BEFORE
directly to the steering wheel. Located under the air-
bag module trim cover are the horn switch, the
folded airbag cushion, and the airbag cushion sup-
porting components. The resistive membrane-type
horn switch is secured with heat stakes to the inside
surface of the airbag module trim cover, between the
trim cover and the folded airbag cushion.
and must be replaced if deployed or in any way dam-
aged. The driver side airbag module trim cover and
the horn switch are available as a unit for service
replacement.
OPERATION
metal housing to which the cushion and an inflator
• REPLACE AIRBAG SYSTEM COMPONENTS
• THE FASTENERS, SCREWS, AND BOLTS ORIG-
HAVE SPECIAL
• WHEN A STEERING COLUMN HAS AN AIRBAG
The driver side airbag module protective trim cover
The driver side airbag module cannot be repaired,
The driver side airbag module includes a stamped
XJ
COATINGS AND ARE