General Description

The Supplemental Air Bag Restraint System is designed to provide increased accident protection for front seat occupants IN ADDITION TO that provided by the three point safety belt system. Safety belt use is necessary to obtain the best occupant protection and to receive the full advantages of the supplemental air bag. FORD RECOMMENDS THE USE OF SAFETY BELT SYSTEMS FOR ALL VEHICLE OCCUPANTS.

System Component Locations:

The Supplemental Air Bag Restraint System consists of two basic subsystems:
1. Driver air bag (and optional passenger air bag)
2. Electrical system, including impact sensors and electronic diagnostic monitor

DRIVER AIR BAG






The driver air bag is mounted in the center of the steering wheel. The module consists of the following components:
^ Inflator
^ Bag Assembly
^ Mounting plate and retainer ring
^ Steering wheel trim cover

CAUTION: The driver air bag is serviced as a complete assembly.

Inflator
The inflator assembly is not a serviceable item. When the sensors close, signaling a crash, battery power flows to the air bag inflator. Inside the inflator, an igniter converts the electrical signal to thermal (heat) energy, causing the ignition of the inflator gas generant. This ignition reaction combusts the sodium azide/copper oxide gas generant in the inflator, producing nitrogen gas, which inflates the air bag.

Driver Air Bag
The air bag is constructed of neoprene coated nylon, is 711 mm (28 inches) in diameter and fills to a volume of about 0.065 cubic meters (2.3 cubic feet) in approximately 40 milliseconds. It is not a serviceable item.

Mounting Plate and Retainer Ring
The mounting plate and retainer ring attach and seal the bag assembly to the inflator. The mounting plate is also used to attach the trim cover and to mount the entire module to the wheel. These items are components of the air bag module and cannot be serviced.

Steering Wheel Trim Cover
When the air bag is activated, tear seams moulded into the steering wheel trim cover separate to allow inflation of the bag. The cover is a component of the air bag module and is not serviceable.

PASSENGER AIR BAG, OPTIONAL

Passenger Air Bag Module:

The passenger air bag is mounted in the RH position of the instrument panel above the glove compartment. The air bag consists of the following components:
^ Inflator
^ Bag Assembly
^ Reaction housing with mounting hardware
^ Trim cover

NOTE: Vehicles that have the letters SRS located above the glove compartment come equipped with a passenger air bag. For vehicles without a passenger air bag, refer to instrument panel cover description.

CAUTION: The passenger air bag is serviced as a complete assembly.

Inflator
The passenger air bag inflator is not a serviceable item. As with the driver air bag, an igniter inside the inflator converts to battery power to thermal (heat) energy, causing ignition of the gas generant. The ignition reaction causes combustion of the sodium azide/iron oxide gas generant producing nitrogen to fill the bag. Since the passenger air bag is much larger than the driver air bag, it contains more gas generant in a different inflator configuration to produce more nitrogen gas.

Trim Cover
The thermo-plastic trim cover is textured and painted to match the surface of the instrument panel. It is constructed with a moulded-in tear seam that separates when the air bag inflates, and hinges out of the way during deployment. Its main function is to retain the air bag in the reaction housing during vehicle operation. It is not a serviceable item.

Passenger Air Bag Delete Bracket






Vehicles which are not equipped with the optional passenger air bag will have the passenger air bag delete bracket. Circuit 49(O) from diagnostic monitor Pin 7, is the optional passenger air bag signal and is grounded for driver only air bag systems. Circuit 49(O) goes to a one way connector near the passenger air bag harness connector. For driver only air bag systems, this connector is secured to the passenger air bag delete bracket which is located behind the finish panel above the glove compartment.

DIAGNOSTIC MONITOR
The diagnostic monitor contains a microcompressor that monitors the electrical system components and connections. The monitor performs a self-check of the microcompressor internal circuits and energizes the system readiness indicator during prove out and whenever a fault occurs. System electrical faults can be detected and translated into coded indicator displays. If a certain fault occurs, the microcompressor will disable the system by opening a thermal fuse built into the monitor. If a system fault exists and the indicator is malfunctioning, an audible tone will be heard signaling the need for service.

An air bag system backup power supply is included in the diagnostic monitor to provide air bag deployment power if the battery or battery cables are damaged in an accident before the crash sensors close. The power supply will deplete its stored energy approximately one minute after the positive cable of the battery is disconnected.

WARNING: The backup power supply energy must be depleted before any air bag component service is performed. To deplete the backup power supply energy, disconnect the positive battery cable and wait one minute.

SYSTEM READINESS INDICATOR






The system readiness indicator will light continuously for approximately six seconds whenever the ignition switch is turned from OFF to RUN if the air bag is working properly. If an air bag system fault is present, the indicator will either fail to light, remain lit continuously, or light in a flashing manner. The flashing manner may not occur until approximately 30 seconds after the ignition switch has been turned from OFF to RUN. This is the time required for the diagnostic monitor to test and verify any and all system faults. If the air bag indicator is inoperative and an air bag system fault exists, a tone will sound signaling that the air bag readiness indicator is inoperative and an air bag system fault exists.

TONE GENERATOR
The air bag readiness indicator is the prime means of determining the air bag system status. However, if the air bag indicator is inoperative and an air bag system fault exists, a tone will sound in a pattern of five sets of five beeps. If this occurs, the air bag indicator will need to be serviced before further diagnosing and testing can be completed. Unless serviced, the Supplemental Air Bag Restraint System may not function properly in the event of an accident.

STEERING COLUMN AND WHEEL
The steering column has a clockspring assembly to transfer electrical signals from the steering column to the steering wheel for the air bag system.