0X930A0A: Right B-Pillar Impact Sensor

Circuit fault

What 0X930A0A means

The B-pillar sensor detects side impact forces at the middle of the vehicle, close to where an intruding door or another car would strike. Reading both x and y axes lets the module tell a true side impact from a hard braking event or an angled frontal hit. Its circuit carries power and data, and the ACSM stores 0X930A0A when it reads supply voltage on the wrong pin or loses the connection entirely.

This sensor bolts to the pillar structure behind the trim, with its harness running down into the sill. That route puts the wiring next to the door opening, where water comes in around a failing door seal and where trim clips get pushed through wires during reassembly. Door and seat belt service both pass through the same panel.

Common causes

• Water and corrosion at the sensor connector from a leaking door or window seal
• Harness damage during B-pillar trim removal or seat belt service
• A connector left unlatched after interior or collision repair
• Insulation chafed against the pillar structure, exposing the wire to a powered conductor
• A sensor that has failed internally and no longer communicates
• Side impact damage that stressed the sensor mount or its wiring

Crash data or hardware fault?

The module is describing a measurement it takes on a schedule, which makes 0X930A0A a live fault. Repair the connection and the code stops returning. A crash record is not a measurement. It is written into module memory when the restraints fire, it records the event, and it cannot be erased with a scan tool at any point afterward.

Does our reset clear it?

Get the circuit right first. Resetting the module leaves a disconnected or shorted sensor exactly where it was, and the next self test logs the same code. Once the sensor reads correctly, a normal code clear finishes the job. If the car was in a side impact and the module carries deployment data, mail the ACSM to us and we clear that record after the body and sensor work.

Which makes throw it

BMW assigns 0X930A0A to the right B-pillar impact sensor. It is read in BMW hex diagnostics on models that use pillar mounted satellite sensors with an ACSM.

What to do next

Start at the right B-pillar trim and look at the connector before testing anything, because water staining and corrosion at that plug explain most of these. Confirm the sensor is tight to the pillar and that no trim clip was driven through the harness. A sensor that stays faulty on clean power and ground needs replacing, and we can source genuine OEM BMW impact sensors. Related codes: 0X930A07, 0X930A0B, B1022.