B159B00 - Fault reported in the control unit airbag control unit fault

What does error code B159B00 mean in the airbag control unit?

Error code B159B00 reports a fault in the control unit itself, that is, in the airbag control unit that monitors and controls the vehicle's airbag systems. The control unit stores the fault in the fault memory and switches on the airbag warning light, so that the driver immediately notices the disturbance in the restraint system and acts on it.

The code therefore concerns the control unit itself and not an individual component such as a sensor or an airbag module. For Audi, this message is known, and it concerns the airbag control unit of the respective vehicle.

The control unit monitors the restraint system continuously and decides in the event of a crash whether the airbags are triggered. If a disturbance exists there, it is stored as a fault and displayed.

How do you recognise error code B159B00?

You can recognise error code B159B00 by the airbag warning light staying lit permanently and the code being stored in the fault memory of the airbag control unit in the vehicle. It is read out with a diagnostic tool, and it cannot be permanently cleared as long as the fault in the control unit actually persists.

The airbag warning light alone does not show the code. Only reading it out with a diagnostic tool makes the entry in the fault memory visible, and there the code is shown together with the description of the fault.

If the airbag warning light stays on even after reading out, the fault persists and must be checked.

What causes error code B159B00?

Error code B159B00 reports an internal fault in the control unit, so the causes usually lie in the control unit itself and not in a cable. Typical causes are crash data after an accident, ageing electronic components, damaged solder joints, moisture or voltage spikes that affect the control unit during operation.

• Crash data stored in the control unit after an accident
• ageing electronic components in the control unit
• damaged solder joints in the control unit
• moisture or corrosion in the control unit
• voltage spikes from a weak battery or a jump start

Crash data remains in the control unit after an accident, even if the vehicle drives normally afterwards. Therefore, an accident should also be considered as a possible cause even if no damage is initially visible.

In which vehicles does error code B159B00 occur?

Error code B159B00 is known on vehicles of the Audi brand, namely on the Audi S3 8YA Sportback, where it occurs in the airbag control unit. The list is not complete, and on other vehicles the meaning of the code may differ, so it is worth checking the specific vehicle.

For other models, the applicability cannot be derived from this page alone, because the assignment covers only the Audi S3 8YA Sportback named here. Whether another vehicle is affected only becomes clear when it is read out with a diagnostic tool.

How is error code B159B00 resolved?

Error code B159B00 is resolved by having the fault memory read out with a diagnostic tool and then sending the airbag control unit to Airbag24 for repair. Because the cause lies in the control unit itself, first disconnect the battery and then remove the control unit.

The process begins with reading out, so that the code is confirmed in the fault memory. Then you create a repair order online, and the unit is sent to Airbag24.

Checking, repairing and testing usually take 3–4 working days. Work on the airbag system should be left to qualified professionals.

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.