Air Bag Systems: Description and Operation

AIRBAG CONTROL MODULE (ACM)
The Airbag Control Module (ACM) contains the safing sensor and energy reserve capacitor. The safing sensor is located inside the ACM. The module is mounted on the tunnel/floor pan in front of the gear shift lever and below the center of the instrument panel.

The safing sensor protects against accidental airbag deployment. The ACM monitors the system to determine the system readiness. The ACM will store sufficient energy to deploy the airbags for up to one second after the battery is disconnected. The ACM contains on-board diagnostics, and Will illuminate the AIRBAG warning lamp in the cluster when a fault is detected. The warning equipment is tested for six to eight seconds every time the vehicle is started.

Clockspring-Typical:

CLOCKSPRING
The clockspring is snapped into a plastic mounting platform on 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.

This assembly consists of a flat ribbon like electrically conductive tape which winds and unwinds with the steering wheel rotation.

DRIVER AND PASSENGER AIRBAG MODULE

WARNING: NEVER DISASSEMBLE THE DRIVER OR PASSENGER AIRBAG MODULE, THERE ARE NO SERVICEABLE PARTS WITH IN THE MODULES.

Airbag System Component Locations:

The Driver Airbag Module located on the steering wheel is the most visible part of the system. The airbag module contains a housing to which the cushion, inflator and cover are attached to.

The driver side inflator assembly is mounted from the back of the module housing. When supplied with the proper electrical signal the inflator assembly will produce a gas and discharge it directly into the cushion. A protective 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.

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 produce 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.

FRONT IMPACT SENSORS
The Driver/Passenger Airbag System is a supplemental safety device designed to help protect the driver/passenger from serious injury, caused by a frontal impact of the vehicle.

The two front impact sensors provide verification of the direction and severity of the impact. The sensors are mounted to brackets on the left and right side of the frame tips near the battery.

The impact sensors are threshold sensitive switches that complete an electrical circuit when an impact provides a sufficient acceleration to close the switch. The sensors are CALIBRATED FOR THE SPECIFIC VEHICLE and react to the severity and direction of the impact.

PASSENGER AIRBAG ON/OFF SWITCH
A Passenger Airbag ON/OFF Switch located in the right instrument panel endcap, allows the passenger side airbag module to be disabled when certain child restraint devices are being used in the right seating position. The passenger airbag ON/OFF switch is equipped with a key cylinder so that the switch position can only be changed using an ignition key. When the ignition switch is in the ON position and the passenger side airbag is disabled, a Light Emitting Diode (LED) illuminates a "PASS AIRBAG OFF" indicator lamp in the instrument cluster.

To actuate the passenger airbag ON/OFF switch, open the passenger door, insert the ignition key in the switch key cylinder. The switch key cylinder is then rotated with the ignition key to its clockwise stop (the key cylinder slot will be aligned with the OFF label on the instrument panel endcap) to disable the passenger side airbag. When the passenger air- bag ON/OFF switch key cylinder is rotated with the ignition key to its counterclockwise stop (the key cylinder slot will be in a vertical position), the instrument cluster indicator lamp will be extinguished and the passenger side airbag module will once again be enabled.

WARNING: THE KEY MUST ALWAYS BE REMOVED FROM THE PASSENGER AIRBAG ON/OFF SWITCH KEY CYLINDER AFTER THE SWITCH HAS BEEN USED. NEVER LEAVE A KEY IN THE PASSENGER AIRBAG ON/OFF SWITCH KEY CYLINDER.

The passenger airbag ON/OFF switch cannot be adjusted or repaired and, if faulty or damaged, the switch assembly MUST be replaced.

WARNING: IN THE EVENT OF AN AIRBAG DEPLOYMENT, THE PASSENGER AIRBAG ON/OFF SWITCH "MUST" BE REPLACED.