B101A11 - Crash sensor, driver front airbag, short circuit to ground airbag control unit fault

What does error code B101A11 mean in the airbag control unit?

Error code B101A11 concerns the crash sensor for the driver-side front airbag. Behind the base code is the fault type, here a short circuit to ground. The airbag control unit stores the fault and switches on the airbag warning light.

The crash sensor tells the control unit how severe an impact is. From this, the control unit decides whether and when the driver's front airbag deploys. If the sensor's wiring is short-circuited, the control unit can no longer use this signal.

This meaning applies to Volkswagen. For Skoda, the same code appears in the fault memory of the Octavia.

How do you recognise error code B101A11?

The airbag warning light stays on permanently. The code is in the fault memory of the airbag control unit, where a diagnostic tool reads it out, and it returns after being cleared.

Driving behaviour and the engine are not affected. The only noticeable sign is the warning light in the instrument cluster. The fact that the code cannot be cleared permanently is an indication that the fault is still present.

What causes error code B101A11?

A short circuit to ground in the crash sensor circuit has several possible causes: the wiring, the connector, the sensor itself or the airbag control unit. Which of these applies is only established by checking the individual components.

• Wiring whose insulation chafes and makes contact with the bodywork.
• A connector with moisture or corrosion on the contacts.
• A faulty crash sensor with a short to ground.
• A fault in the evaluation electronics of the control unit, for example due to aged components or solder joints.

Crash data after an accident, or voltage spikes caused by a weak battery or jump-starting, can also leave entries in the control unit.

In which vehicles does error code B101A11 occur?

Error code B101A11 is known, among others, in the Volkswagen T-Roc A1 and the Skoda Octavia 3. The list is not complete, and in other vehicles the code may mean something different.

Whether your vehicle is affected is ultimately decided by the fault memory that has been read out.

How is error code B101A11 resolved?

First have the fault memory read out with a diagnostic tool, and have the connector, wiring and crash sensor checked in a specialist workshop. If the fault remains, the cause lies in the control unit, which you can send in to Airbag24 for repair.

If the check shows no fault at the connector, wiring or sensor, disconnect the battery and remove the airbag control unit. Create a repair order online and send the unit to Airbag24. Checking, repairing and testing usually take 3–4 working days.

The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

Work on the airbag system belongs in expert hands. This applies to removing the control unit just as much as to any check of connectors, wiring and sensors.