Vehicle: 2003 Ford Expedition, 4WD, V8-5.4L SOHC, VIN L
Problem: This vehicle was brought to the shop because the malfunction indicator light (MIL) and the air bag warning light was on.
Case Details: The technician connected a scan tool to check for diagnostic trouble codes (DTCs). He retrieved only one DTC:
C1981 - SEAT TRACK POSITION SENSOR CIRCUIT FAULT
When the technician called ALLDATA Tech-Assist, he was advised that the air bag system on this vehicle uses seat track position to determine air bag ignition deployment force. If there is a seat track position error, the air bag system will show a fault. The consultant further advised that It would be best to begin the diagnosis by removing the seat to check for continuity between the sensors and connectors. While testing the circuits, the technician found an open in the wire between pin 23 of the restraints control module (in connector C313) and pin 2 of the seat position sensor, driver (in connector C356).
Confirmed Repair: The technician repaired the open wire, cleared the DTC, cycled the seat back and forth a few times and test drove the vehicle. The air bag light did not return. Problem solved!