The Air Bag system or Supplemental Restraint System (SRS) is designed to provide additional protection for front seat occupants when used in conjunction with a seat belt. The system is an electronically controlled, mechanically operated system. The system contains two basic subsytems: the air bag module(s) (the actual air bag(s) themselves), and the electrical system. The system consists of:
The system is operates as follows: The system remains out of sight until activated in an accident that is determined to be the equivalent of hitting a parked car of the same size and weight with the vehicle receiving severe front end damage. This determination is made by crash and safing sensors mounted on the vehicle which when an sufficient impact occurs, close their contacts completing the electrical circuit and inflating the air bags. When not activated the system is monitored by the air bag diagnostic monitor and system readiness is indicated by the lamp located on the instrument cluster. Any fault detected by the diagnostic monitor will illuminate the lamp and store a Diagnostic Trouble Code (DTC).
Whenever working around, or on, the air bag supplemental restraint system, ALWAYS adhere to the following warnings and cautions.
DISARMING THE SYSTEM
The back-up power supply for the air bag is in the control unit. It will drain down by itself after the battery is disconnected but this takes about 20 minutes. Do not use a computer memory saver device. It will keep the back-up power supply charged. If it is necessary to remove the steering wheel, disconnect the negative battery cable and wait at least 20 minutes for the power supply to discharge. To remove the air bag unit, remove the Torx® screws on either side of the back of the steering wheel. The screws must be replaced when removed. Tilt the unit down and disconnect the wire. Place the air bag unit face up where it will not be disturbed and do not place anything on top of it.
- Position the vehicle with the front wheels in a straight ahead position.
- Disconnect the negative battery cable.
- Disconnect the positive battery cable.
- Wait at least twenty (20) minutes for the air bag back-up power supply to drain before continuing.
- Proceed with the repair.
ARMING THE SYSTEM
- Connect the positive battery cable.
- Stand outside the vehicle and carefully turn the ignition to the RUN position. Be sure that no part of your body is in front of the air bag module on the steering wheel, to prevent injury in case of an accidental air bag deployment.
- Connect the negative battery cable.
- Ensure the air bag indicator light turns off after approximately 6 seconds. If the light does not illuminate at all, does not turn off, or starts to flash, have the system tested by a qualified automotive technician. If the light does turn off after 6 seconds and does not flash, the SRS is working properly.