Ford Pick-ups and Broncos 1987-1996 Repair Guide



See Figure 1

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Fig. Fig. 1: Air bag firing circuit diagram

The sensors are an electrical switch which reacts to impacts according to direction and force. It discriminates between impacts that require air bag deployment and impacts that do not. When an impact occurs that requires deployment, the sensor contacts close, completing the electrical circuit necessary for the system to operate.

The sensors are located in the vehicle in several places. A primary crash sensor and bracket are located on the left and right front radiator supports. The safing rear air bag sensor is located in the left kick panel in the passenger's compartment. The safing and one of the primary sensors must be activated simultaneously to inflate the air bag.


Always wear safety glasses when servicing an air bag vehicle and handling the air bag to avoid possible injury.

Carry a live air bag with the bag and trim cover pointed away from your body.
Place a live air bag on a bench or other surface with the trim cover up, away from the surface.
After deployment, the air bag surface may contain deposits of sodium hydroxide. This is a product of the gas generant combustion that is irritating to the skin.
Wash your hands immediately with a mild soap after handling a deployed air bag.
You can only replace, NOT service the crash sensors, sliding contact, diagnostic monitor and air bag modules.
If the air bag module has a discolored or damaged trim cover deployment door it must be replaced. Do not attempt to paint it, any paint applied may damage the cover material. This could affect the air bag performance during deployment, which could cause personal injury.
Never probe the connectors on the air bags. This may result in air bag deployment.
All component replacement must be done with the negative battery cable disconnected for as minimum of one minute before service or replacement is attempted.


See Figure 2

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Fig. Fig. 2: Disarm the air bag as shown and use a suitable air bag simulator at the connection

The Rotunda Air Bag Simulator 105-00010 is a 2 ohm resistor that simulates an air bag connection. This special jumper must be used, and NOT an ordinary 0 ohm wire to prevent tripping diagnostic trouble code 34 or 35.

  1. Disconnect the POSITIVE battery cable.
  3. Wait one minute. This is the time required for back-up power supply to be depleted from the air bag diagnostic monitor.
  5. Remove the 4 nuts and washers holding the sir bag module to the steering wheel.
  7. Disengage the air bag electrical connector.

Some abnormal drive symptoms may be detected when the power supply has been disconnected until the PCM can re-learn its adaptive strategy.

  1. Connect the Rotunda Air Bag Simulator 105-00010, or equivalent to the vehicle harness at the top of the steering wheel.
  3. Connect the positive battery cable.


The air bag simulators must be removed and the air bags reconnected when the system is reactivated to avoid non-deployment in a collision resulting in possible personal injury.

  1. Disconnect the positive battery cable.
  3. Wait one minute, this is required for the back-up power supply in the air bag diagnostic monitor to deplete its stored energy.
  5. Remove the air bag simulator from the air bag sliding contact connector at the top of the steering column. Reconnect the driver's side air bag module assembly. Position the driver's air bag module on the steering wheel and secure with the 2 bolts and washers. Tighten the bolt and washer assembly to 8-10 ft. lbs. (10-14 Nm).
  7. Connect the positive battery cable.
  9. Turn the ignition switch from the OFF to RUN and visually monitor the air bag warning indicator. The light will illuminate continuously for approximately 6 seconds and then turn off. If a fault occurs, the air bag indicator will either fail to light, remain lighted continuously or flash. The flashing may not occur until approximately 30 seconds after the ignition switch has been turned from OFF to RUN . This is the time needed for the air bag diagnostic monitor to complete testing the system. If the air bag indicator is inoperative, an air bag system fault exists, a tone will sound in a pattern of 5 sets of 5 beeps. If this occurs, the air bag indicator will need to be serviced before further diagnostics can be done.