This BMW code says the driver airbag stage 1 loop is shorted to positive. Battery or switched voltage has found its way onto a firing circuit that is supposed to stay isolated, and the ACSM disables the system over it.
The stage 1 firing loop is held at a controlled low voltage so the module can measure it accurately. When the module instead reads supply voltage on one of those two wires, it knows something outside the loop is feeding it. That condition is dangerous enough that the controller stores 0X930902 and refuses to arm, since an uncontrolled voltage on a firing circuit is exactly what a restraint system is designed to prevent.
Where to look depends on what runs next to the airbag wiring. Under the dash, the firing loop shares space with power feeds for the cluster, the lighting, and any accessory wiring somebody added later. In the column, a worn clockspring ribbon can bridge the firing circuit against the horn feed or a steering wheel switch wire. Both produce the same reading at the module.
0X930902 tracks a measurement the module takes right now, which puts it in the live fault group rather than the crash record group. Once the unwanted voltage is gone, the condition clears. A crash record behaves in the opposite way. It is created at deployment, describes an event rather than a measurement, and no amount of code clearing removes it.
Clearing this code without finding the source of the voltage leaves an unsafe circuit in the car. The module is not confused, it is reporting real voltage where none belongs. Repair the short, verify the loop reads correctly, then clear. If the car was in a collision and the ACSM is also locked by crash data, we clear that part through our mail-in module reset once the wiring work is finished.
BMW is the make that uses 0X930902. It belongs to the BMW hex fault code set read by BMW factory and aftermarket scan software on vehicles with an ACSM.
Disconnect the battery and let the system stand down before probing anything, then inspect for added wiring under the dash and around the column, since aftermarket installs cause a large share of short-to-positive faults. Check the clockspring next. Once the extra voltage source is found and removed, recheck the loop resistance to confirm the airbag itself was not damaged by it. Related codes: 0X930901, 0X930904, 12-1X.
Trace the wiring and connectors first. If the module still holds the fault after the repair, mail it to us and we will clear it.
Genuine OEM, tested, and shipped ground from Jacksonville, Arkansas.
Do not see it listed? Request a part or call 501-988-0611.