B1C12 - Driver Active Headrest Control Circuit Low: Notes

For wiring diagram information, refer to appropriate SYSTEM WIRING DIAGRAMS article.

Theory of Operation

The Driver Active Headrest signal circuit is driven by a solenoid that also uses a diode in parallel. The single electrical component of the AHR (Active Headrest) unit is the latch-release solenoid. The solenoid is connected by a 2 way pigtail wire and harness connector. The pigtail wire and 2 way connector are routed through the center of one of the headrest support posts and down through the guide sleeve to the interior of the seat back, where it connects to the seat wire harness. The solenoid is grounded at an independent dedicated ground. The AHR components itself cannot be repaired. If damaged or ineffective, the AHR must be replaced as a new assembly. If upon inspection the AHR has deployed it can be reset following the proper reset method. Refer to Description and Operation . Also if the already deployed Driver or Passenger AHR are latched in the locked position please see the scan tool miscellaneous functions to set the latch in the unlock or deployed position. Please be very observant and careful, the scan tool should never be used to actually deploy a known good non-deployed Driver or Passenger AHR.

• >>When Monitored:<< The Occupant Restraint Controller (ORC) monitors the Passenger Active Headrest during the start up phase of the ORC module. The Passenger Active Headrest communication and on board diagnostics are powered by the ORC signal.
• >>Set Condition:<< This DTC will set, if the ORC detects low voltage on the Active Head Restraint 1st Row Passenger Signal circuit (R677).

Possible Causes
ACTIVE HEAD RESTRAINT 1ST ROW DRIVER SIGNAL CIRCUIT R676 SHORTED TO GROUND
DRIVER ACTIVE HEADREST
OCCUPANT RESTRAINT CONTROLLER

Always perform the Pre - Diagnostic Troubleshooting procedure before proceeding.