BMW Airbag (SRS) Light On? How to Read the Codes and Find the Cause

An airbag light means the airbag system has switched itself off, at least in part. It's a safety problem worth fixing properly, and the good news is that the airbag module stores a fault code that points to exactly which part is causing it. A basic OBD2 reader can't see that module. PASOFT can.

Read the airbag codes

1. Connect PASOFT with the ignition off, then switch the ignition ON (engine off).
2. Let PASOFT identify the car, then open the SRS module.
3. Read the error list. Each code names the circuit or sensor at fault, for example a passenger seat sensor, a seatbelt buckle switch or the driver's airbag circuit.
4. Save or write down the codes before you do anything else.

PASOFT can also show SRS live data on MRS2 and MRS4 modules, which helps you check sensors as you go.

Common causes on classic BMWs

• Passenger seat occupancy mat: a very common failure in the E46 and E39. The sensor in the seat cushion breaks over time.
• Seatbelt buckle switches and loose seat connectors, especially after the seats have been removed.
• Clockspring (steering wheel slip ring): a driver's airbag circuit fault often points here.
• Side airbag connectors under the seats or in the doors.
• A low battery during cranking, which can leave a stored code.

Clear the light once it's fixed

On cars with an MRS4 airbag module, PASOFT can clear the SRS fault codes. (PASOFT shows the module type when it identifies the car.) After the repair, clear the codes, switch the ignition off and on, and check that the light goes out after its normal self-test.

If the light comes straight back, the fault is still present. Clearing the code won't hide a real problem, and we don't support disabling any part of the airbag or seatbelt system.

Safety first

• Disconnect the battery and wait several minutes before unplugging any airbag connector.
• Never probe airbag connectors with a test light or multimeter.
• If you're not comfortable working on airbag parts, use PASOFT to find the fault and let a shop do the repair. You'll still save on diagnosis.

Get set up

The PASOFT Scanner Kit includes the USB interface, cable and PASOFT software, with free remote setup support. If your car has the round 20-pin port under the hood, get the Kit + 20-Pin Adapter Bundle instead. Questions about your car? Email info@bmwpasoft.com with your model and year.