Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Air Bag Supplemental Restraint System (SRS)
Special Tool(s)
Diagnosing Customer Concerns Without Hard Diagnostic Trouble Codes (DTCs)
If a lamp fault code (LFC) is reported by the customer but is not present when the vehicle comes in for repair, follow the Diagnostic Instructions procedure in this section to identify the intermittent DTC.
Once the DTC is known, read the Normal Operation section for the code involved.
Follow the deactivation procedure in this section.
Determine the location of components involved in creating that code.
Perform a thorough visual inspection of:
components.
connectors.
splices and wiring harnesses.
pinched wires.
worn insulation on conductors.
opens, shorts or loosely mounted sensors.
Refer to Possible Causes, which lists the common concerns that relate to a particular code. Concerns are listed according to priority.
Diagnosing Customer Concerns with Hard Diagnostic Trouble Codes (DTCs)
Most air bag supplemental restraint system (SRS) diagnostic procedures will require the use of the deactivation and reactivation procedures in this section. These procedures require the removal of the driver air bag module and disconnection of the passenger air bag module, thereby removing the risk of air bag deployment while diagnostics are performed.
Air bag simulators are required to perform diagnosis and testing of the SRS. The air bag simulator is a 2-ohm resistor used to simulate air bag module connections to the system. It is not acceptable to short-circuit the air bag module connections with a zero-ohm jumper wire. If a zero-ohm jumper wire is used to short-circuit the air bag module connections, a lamp fault code (LFC) will be displayed.
Deactivation Procedure
1. WARNING: To avoid accidental deployment and possible personal injury, the backup power supply must be depleted before repairing or replacing any air bag supplemental restraint system (SRS) components. To deplete the backup power supply energy, disconnect the battery ground cable and wait one minute. Be sure to disconnect auxiliary batteries and power supplies (if equipped).
Disconnect the battery ground cable (14301).
2. Wait one minute for the backup power supply in the air bag electronic crash sensor (ECS) module to deplete its stored energy.
3. WARNING: Carry a live air bag module with the air bag and trim cover pointed away from your body. This will reduce the risk of injury in the event of an accidental deployment.
WARNING: Do not set a live air bag module down with the trim cover face down.
Remove the driver air bag module from the vehicle.
4. Connect an air bag simulator to the vehicle harness at the top of the steering column.
5. WARNING: Carry a live air bag module with the air bag and deployment door pointed away from your body. This will reduce the risk of injury in the event of an accidental deployment.
WARNING: Do not set a live air bag module down with the deployment door face down.
Remove the passenger air bag module from the vehicle.
6. Connect an air bag simulator to the vehicle harness.
7. Reconnect the battery ground cable.
Reactivation Procedure
1. WARNING: The air bag simulators must be removed and the air bag modules reconnected when the system is reactivated to avoid non-deployment in a collision, resulting in possible personal injury.
Disconnect the battery ground cable.
2. Wait one minute for the backup power supply in the air bag electronic crash sensor (ECS) module to deplete its stored energy.
3. Remove the air bag simulator from the vehicle harness connector at the top of the steering column.
4. WARNING: Carry a live air bag module with the air bag and trim cover pointed away from your body. This will reduce the risk of injury in the event of an accidental deployment.
Install the driver air bag module.
5. Remove the air bag simulator from the vehicle harness connector at the passenger air bag module.
6. WARNING: Carry a live air bag module with the air bag and deployment door pointed away from your body. This will reduce the risk of injury in the event of an accidental deployment.
Install the passenger air bag module.
7. Reconnect the battery ground cable.
8. Prove out the system.
Glossary
Air Bag Simulator
Air bag simulators are used to simulate air bag module connections to the system.
Disconnect the Component
Disconnect the component means disconnect the component vehicle harness connector. It does not mean remove the component. Do not reconnect a disconnected component unless instructed to do so.
Deactivate the System
Deactivate the system means to perform the deactivation procedure. Refer to Deactivation Procedure in this section.
Prove Out the System
Prove out the system means to turn the ignition switch from the OFF to the RUN position and visually monitor the air bag indicator with the air bag modules installed. The air bag indicator will light continuously for approximately six seconds and then turn off. If an air bag supplemental restraint system (SRS) fault is present, the air bag indicator will either:
fail to light.
remain lit continuously.
flash.
The flashing might not occur until approximately 30 seconds after the ignition switch has been turned from the OFF to the RUN position. This is the time required for the air bag electronic crash sensor (ECS) module to complete the testing of the SRS. If the air bag indicator is inoperative and an SRS fault exists, a chime will sound in a pattern of five sets of five beeps. If this occurs, the air bag indicator will need to be repaired before diagnosis can continue.
Reactivate the System
Reactivate the system means to perform the reactivation procedure. Refer to Reactivation Procedure in this section.
Reconnect the System
Reconnect the system means to reconnect all system components. Refer to Air Bag System Reconnect Checklist in this section.
Install a New Component
Install a new component means to remove the existing component and install an authorized replacement part obtained from Ford Customer Service Division.
Verify the System
Verify the system means to prove out the system with air bag simulators for the air bag modules in place of the components.
Air Bag Reconnect Checklist
The checklist below should be completed following diagnosis or repair of any air bag system concern:
1. Is the three-way connector at the base of the steering column connected?
2. Are the air bag modules connected?
3. Is the air bag electronic crash sensor (ECS) module connected?
4. Is the vehicle battery connected?