0X930A1C: Occupancy Mat Moisture Fault

Hardware fault

What 0X930A1C means

The occupancy mat is a thin sensing layer inside the passenger seat cushion, and its readings depend on electrical properties that water changes. When liquid soaks into the foam, it creates conductive paths between sensing elements that the mat was never designed to have. The ODS electronics recognize that signature and report a moisture caused sensor fault rather than a generic failure.

What makes this code useful is that the damage is sometimes reversible and sometimes not. A cushion that simply got wet may dry out and report normally again. A cushion that stayed wet long enough for the mat elements to corrode will keep failing after it dries. The difference comes down to how long the moisture sat there and what was in it.

Common causes

• A spilled drink soaked into the passenger seat cushion
• Water entering through an open window, sunroof, or a leaking door or windshield seal
• A car washed or detailed with too much water on the upholstery
• Condensation or flood water that reached the seat foam
• A leaking sunroof drain running down inside the seat area
• Corrosion in the mat elements left behind after an earlier soaking

Crash data or hardware fault?

BMW files this as a hardware fault, which means the module is pointing at a physical part rather than at the wiring leading to it. Crash data is a separate category entirely. It is the permanent record created when the restraint system fires, it survives every scan tool clear, and it has nothing to do with a wet seat cushion.

Does our reset clear it?

Drying the seat comes before any electrical work. Pull the cushion, dry it thoroughly, and recheck, since a mat that recovers makes the rest of the job unnecessary. A reset does not dry anything and does not repair a corroded mat, so it is not the fix for a live moisture fault. Where the module also holds crash data from a deployment, our mail-in reset service handles that part.

Which makes throw it

0X930A1C is a BMW code covering the ODS occupancy mat in BMW passenger seats. The moisture specific wording comes from BMW diagnostic software.

What to do next

Find and stop the water source first, because replacing a mat under a leaking sunroof drain just buys you a second failure. Remove the seat cushion and let it dry completely before retesting the mat. If the fault stays after the cushion is dry, the mat has corroded and the cushion or mat assembly needs replacing. Call 501-988-0611 if you want the module checked for stored crash data at the same time. Related codes: 0X930A14, 0X930AB6, 01222.