Airbag control unit with part number 2Q0 959 655 BK

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

The airbag control unit 2Q0 959 655 BK is the central control unit of the restraint system (SRS) of Audi. It evaluates sensor signals, decides in a collision within milliseconds which airbags and seatbelt pretensioners trigger, and monitors the system constantly.

During operation the unit checks the connected components in the background. If it finds a fault, it reports it via the airbag warning light in the instrument cluster, so the driver can react in good time.

In addition, the manufacturer number Bosch 0285020503 is printed on the housing. After an accident the unit stores crash data and locks itself, a behaviour that belongs to the system.

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

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

An ordinary diagnostic tool cannot delete this crash data. Airbag24 deletes it during the repair, so that it is no longer stored in the unit afterwards.

The other causes concern the unit itself and its connections. Components age, solder joints become cold, and moisture and corrosion disturb plug connections. Voltage spikes, for example from a weak battery or jump-starting, add further stress.

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

The airbag warning light in the instrument cluster lights up permanently or intermittently, a fault message appears in the instrument cluster, the diagnostic tool cannot connect to the control unit, or the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then possibly fail to deploy.

• airbag warning light that is on permanently or intermittently
• fault message in the instrument cluster
• no connection between diagnostic tool and control unit
• fault memory that cannot be cleared

When one of these signs appears, have the system checked promptly. The read-out shows which fault is stored.

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

The airbag control unit 2Q0 959 655 BK is fitted in these vehicles: Audi A1 GB (from 2018). Whether your car is among them, compare it with this list.

The vehicles in detail:

• Audi A1 GB (from 2018)

Comparing the label of the removed unit with this page only ensures that you have the correct unit. Have the fault memory read out beforehand, because it shows whether the control unit is defective or 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 BK work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit. Then create a repair order online and send in the well-packed unit. Airbag24 checks it on the test bench, repairs defective components, deletes the crash data and carries out a function test.

Processing at Airbag24 usually takes 3–4 working days. This time applies exclusively to checking, repairing and testing.

Afterwards 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 BK get to Airbag24?

You send the control unit 2Q0 959 655 BK as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back by UPS.

Place the printed repair order in the parcel and pack the control unit shock-proof.