Airbag control unit with part number 2Q0 959 655 BJ

What does the airbag control unit 2Q0 959 655 BJ do?

The airbag control unit 2Q0 959 655 BJ is the central control unit of the restraint system (SRS) for Audi. It evaluates the signals from the crash sensors, decides in an accident within milliseconds on the firing of airbags and seatbelt pretensioners, and monitors the system continuously.

The unit shows faults via the airbag warning light, so the state of the system stays visible. The manufacturer number Bosch 0285020502 is also printed on the housing.

After an accident it stores crash data and locks itself.

Why does the control unit 2Q0 959 655 BJ fail?

The most common cause is crash data stored after an accident, even if no airbag has fired. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage peaks.

Crash data cannot be erased with an ordinary diagnostic tool. Airbag24 erases it during the repair. The other causes act over a longer period, for example when moisture causes corrosion on plugs.

How can you tell that the 2Q0 959 655 BJ is defective?

The airbag warning light lights up permanently or intermittently, and a fault message appears in the instrument cluster. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

• The diagnostic tool gets no connection to the control unit.
• The fault memory cannot be cleared.

The warning light is the clearest sign. However, the display says nothing about the cause.

Which vehicles is the 2Q0 959 655 BJ fitted in?

The control unit 2Q0 959 655 BJ is fitted in these vehicles: Audi A1 GB (from 2018).

These models are recorded for this part number:

• Audi A1 GB (from 2018)

On the one hand, compare the part number on the label of the removed unit with this page. This only ensures that it is the correct unit. On the other hand, have the fault memory read out before removal. Only this result shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 2Q0 959 655 AK, 2Q0959655AC.

How does the repair of the 2Q0 959 655 BJ work?

You first have the fault memory read out and attach the log. Then you disconnect the battery and only then remove the control unit. Next, create a repair order online and send the well-packed unit.

Airbag24 tests the unit on the test bench, replaces defective components and erases the stored crash data. A function test follows. At Airbag24, testing, repairing and testing usually take 3–4 working days. After that your own unit goes back to you.

Our repairs come with 2 years' statutory liability for defects. 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.

How does the control unit 2Q0 959 655 BJ get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Put the printed repair order into the parcel. Pack the control unit shock-proof.