EXPEDITION WITH MIL AND AIR BAG LIGHTS ON – DTC C1981
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!