DESCRIPTION AND OPERATION
AIRBAG CONTROL MODULE (ACM)
The Airbag Control Module (ACM) contains the
impact sensor and energy reserve capacitor. The
impact sensor acts as a threshold sensitive switch
that completes a circuit when an impact provides suf-
ficient deceleration. The sensor is calibrated for the
specific vehicle and reacts to the severity and direc-
tion of the impact.
The ACM monitors the system to determine the
system readiness. The ACM stores sufficient energy
to deploy the airbags for approximately two minutes
after the battery is disconnected. The ACM contains
on-board diagnostics, and illuminates the AIRBAG
warning lamp in the cluster when a diagnostic trou-
ble code occurs. The warning equipment is tested for
a few seconds every time the vehicle is started.
CLOCKSPRING
The clockspring is mounted to the steering column
behind the steering wheel. The clockspring is used to
maintain a continuous electrical circuit between the
wiring harness and the:
• Driver’s airbag module
• Speed control switches
• Horn switch
The clockspring consists of a flat, ribbon like, elec-
trically conductive tape that winds and unwinds with
the steering wheel rotation.
DRIVER AND PASSENGER AIRBAG MODULES
WARNING: NEVER DISASSEMBLE THE DRIVER OR
PASSENGER AIRBAG MODULES, THERE ARE NO
SERVICEABLE PARTS WITHIN THE MODULES.
The Driver Airbag Module located in the center of
the steering wheel is the most visible part of the sys-
tem (Fig. 1). It contains the airbag cushion and its
supporting components. The airbag module contains
a housing in which the cushion and inflator are
attached and sealed.
The driver side inflator assembly is mounted from the
back of the module housing. When supplied with the
proper electrical signal, the inflator assembly produces
a gas and discharges it directly into the cushion. A pro-
tective cover is fitted to the front of the Driver Airbag
Module and forms a decorative cover in the center of the
steering wheel. The Driver Airbag Module is mounted
directly to the steering wheel.
The Passenger Airbag Module is located beneath
the decorative cover of the instrument panel, facing
the passenger seat (Fig. 1).
The passenger inflator assembly is within the module
housing. The module is mounted to the instrument
panel retainer and support structure. When supplied
with the proper electrical signal the inflator will pro-
duce a gas and discharge it directly into the cushion. A
protective cover is fitted into the instrument panel over
the airbag module and forms a decorative cover.
The Passenger Airbag Module (PAB) consists of:
• Inflator assembly
• Reaction canister
• Airbag Pillow
• Deployment door
The PAB module is mounted to the instrument
panel and pad assembly. When supplied with the
proper electrical signal, the inflator produces gas and
discharges it directly into the pillow. The deployment
door will hinge, allowing the pillow to fully inflate.
DIAGNOSIS AND TESTING
AIRBAG SYSTEM TEST
(1) Connect the DRB lllt scan tool to the Data
Link connector which is located on the left side kick
panel just above the hood release.
(2) Turn the ignition key to the ON position. Exit
vehicle with the scan tool.
(3) After checking that no one is inside the vehicle,
connect the battery negative remote terminal.
(4) Using the scan tool, read and record the active
Diagnostic Trouble Code (DTC) data.
(5) Read and record any stored DTC’s.
(6) Refer to the proper Body Diagnostic Procedures
Manual if any DTC’s are found in Step 4 and Step 5.
(7)
Erase stored DTC’s if there are no active codes. If
problems remain, DTC’s will not erase. Refer to the
proper Body Diagnostic Procedures Manual to diagnose
the problem. If the airbag warning lamp either fails to
light, or goes on and stays on, there is a system mal-
function. Refer to the proper Body Diagnostic Proce-
dures Manual to diagnose the problem. To test the
airbag warning lamp operation in the cluster only, refer
to Group 8E, Instrument Panel and Systems.
Fig. 1 Driver and Passenger Airbag Modules
8M - 2 PASSIVE RESTRAINT SYSTEMS JA
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