The Supplemental Restraint System (SRS), found on all vehicles covered by this guide, is designed to be used along with the front seat belts to reduce the risk or amount of injury by deploying one or both air bags during certain frontal collisions.
The air bag system is made up of left and right front impact sensors, air bag modules for the driver (in the steering wheel) and front passenger (right side instrument panel above the glove compartment), SRS diagnosis unit (with a safing sensor) and a SRS warning lamp in the instrument cluster.
The SRS system is designed to deploy when the safing sensor, along with either or both of the impact sensors, simultaneously activate while the ignition is ON . The sensors will activate during frontal or near-frontal impacts of moderate to severe force.
See Figure 1
When working on the SRS or any components which require the removal of the air bag, adhere to all of these precautions to minimize the risks of personal injury or component damage:
At no time should any source of electricity be permitted near the inflator on the back of the module. When carrying a live module, the trim cover should be pointed away from the body to minimize injury in the event of accidental deployment. In addition, if the module is placed on a bench or other surface, the plastic trim cover should be face up to minimize movement in case of accidental deployment.
When handling a steering column with an air bag module attached, never place the column on the floor or other surface with the steering wheel or module face down.Handling a Deployed Air Bag Module
The vehicle interior may contain a very small amount of sodium hydroxide powder, a by-product of air bag deployment. Since this powder can irritate the skin, eyes, nose or throat, be sure to wear safety glasses, rubber gloves and long sleeves during cleanup.
If you find that the cleanup is irritating your skin, run cool water over the affected area. Also, if you experience nasal or throat irritation, exit the vehicle for fresh air until the irritation ceases. If irritation continues, see a physician.
Begin the cleanup by putting tape over the two air bag exhaust vents so that no additional powder will find its way into the vehicle interior. Then, remove the air bag(s) and air bag module(s) from the vehicle.
Use a vacuum cleaner to remove any residual powder from the vehicle interior. Work from the outside in so that you avoid kneeling or sitting in an uncleaned area.
Be sure to vacuum the heater and A/C outlets as well. In fact, it's a good idea to run the blower on low and to vacuum up any powder expelled from the plenum. You may need to vacuum the interior of the car a second time to recover all of the powder.
Check with the local authorities before disposing of the deployed bag and module in your trash.
After an air bag has been deployed, the air bag module and clockspring must be replaced because they cannot be reused. Other air bag system components should be replaced with new ones if damaged.
DISARMING THE SYSTEM
- Position the front wheels straight ahead.
- Place the ignition switch in the LOCK position, then remove the ignition key.
- Disconnect the negative battery cable. Isolate the battery cable by taping up any exposed metal areas of the cable. This will keep the cable from inadvertently contacting the battery and causing accidental deployment of the air bag.
- Allow the system capacitor to discharge for at least 2 minutes, although 10 minutes is recommended to allow the dissipation of any residual energy.
ARMING THE SYSTEM
A DRB or equivalent scan tool is necessary to test the SRS after the system has been rearmed. If no scan tool is available, arm the system by simply removing the tape and reconnecting the negative battery cable.
If a scan tool is available, perform the following procedure:
- Connect a DRB or equivalent scan tool to the Data Link Connector (DLC), located near the steering column and at the lower edge of the lower instrument panel.
- Turn the ignition key to the ON position. Get out of the vehicle with the scan tool. Make sure you are using the latest version of the proper cartridge.
- After making sure no one is in the vehicle, remove the tape, then reconnect the negative battery cable.
- Read and record any stored Diagnostic Trouble Codes (DTCs). If any diagnostic trouble codes are recorded, take your vehicle to a reputable repair shop for diagnosis.
- If there are no DTCs, and if the AIRBAG warning lamp either fails to light, with the ignition switch ON , or the light goes on and stays on, there is a system malfunction. If any of these conditions exist, you should take your vehicle to a reputable repair shop for diagnosis.