Driver Power Head Restraint Operation

WARNING: This page is about a different car, the 2018 Lincoln Continental. However, it is still accessible from the selected car via links, so may be relevant.

The power head restraint assembly contains a seat headrest motor (up/down) and a seat head restraint forward/rearward motor. The driver seat control switch communicates over a LIN to the DSM. When the DSM receives the input from the seat control switch, the DSM provides power the appropriate head restraint motor until the input is removed. The motor circuits are normally grounded through the DSM. The DSM internally switches the appropriate circuit from ground to voltage to operate the motors.

If the DSM loses the signal from any of the motor position sensors, the affected head restraint motor operates in jog mode. Jog mode allows limited operation of the affected head restraint motor using the seat control switch. When the seat control switch is operated in jog mode, the head restraint moves in the desired direction for one second, then stops. The seat control switch must be released, then pressed again in order to move the head restraint for an additional second. Jog mode is an indication that there is a head restraint motor sensor fault. If the head restraint is operating in jog mode, a DTC sets in the DSM.

As the driver seat head restraint is adjusted, the DSM monitors the motor position sensors to record the current seat position. The DSM removes voltage from the motor upon termination of the seat control switch input or if the DSM does not detect movement from the motor while monitoring the position sensor during a memory recall operation.