0X930955: Driver Active Head Restraint

Circuit fault

What 0X930955 means

The driver active head restraint is a device inside the seat back that releases or drives the headrest forward when the module detects a rear collision. It is triggered electrically, so the ACSM keeps a monitored circuit running to it. When one of those wires reads chassis potential, the module can no longer confirm the device is isolated and it stores 0X930955.

All the wiring for this device lives in the seat, which is a moving assembly. The harness runs from the floor connector up through the seat frame and into the seat back, crossing the recliner area where the back pivots. Every one of those movements works the wire a little, and the connector at the floor gets exposed every time the seat comes out.

Common causes

• Harness worn or grounded where it crosses the seat recliner pivot
• A seat floor connector left unlatched or damaged during seat removal
• Wiring crushed under the seat rail or trapped in the seat frame
• Corrosion at the seat connector from wet carpet
• An internal short in the head restraint actuator
• Damage from aftermarket seat covers, upholstery work, or seat heater installation

Crash data or hardware fault?

0X930955 is a live circuit report. The module reads the head restraint circuit during its self test and writes what it sees, so a proper repair makes the entry go away. Crash records are unrelated to any of that. They are set at deployment, they describe an event, and a scan tool cannot erase them from module memory.

Does our reset clear it?

Clearing codes does not lift a short off a seat harness. Repair the wiring or replace the actuator first. Some active head restraints are mechanical and resettable after a rear impact while others are single use, so confirm what the vehicle has before deciding what to order. If the ACSM is locked with crash data from that impact, mail it to us and we clear the record once the seat is right.

Which makes throw it

BMW uses 0X930955 on models with electrically triggered active head restraints. It is read in BMW hex diagnostics and is not a code you will see listed on other makes.

What to do next

Move the seat forward, back, and through its recline range while watching the fault status, because a wire failing at the recliner pivot shows up as an intermittent that tracks seat position. Then unplug the seat at the floor connector and measure from both directions to isolate the seat harness from the body harness. Call 501-988-0611 if you need a genuine OEM seat component for that repair. Related codes: 0X930949, 0X930961, B0052-13.