Airbag control unit with part number 8U0959655C

What does the airbag control unit 8U0959655C do?

The airbag control unit 8U0959655C is the central control unit of the restraint system (SRS) of Audi. It processes the signals from the crash sensors and, in the event of an accident, decides within milliseconds which airbags and seatbelt pretensioners to trigger. After an accident it stores crash data and locks itself.

The system is monitored continuously, and faults appear via the airbag warning light in the instrument cluster.

The control unit is connected by cable to sensors and triggers, which must work flawlessly in an emergency.

Why does the control unit 8U0959655C fail?

The most common cause is crash data stored after an accident, even without a deployed airbag, and a standard diagnostic tool cannot remove it. Other possible causes include aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes.

The crash data is created when the unit detects an impact. It then remains in the memory and cannot be erased by conventional means.

The other causes have nothing to do with the accident. Components age over time, solder joints can go cold, and moisture attacks contacts. Fluctuations in the vehicle's voltage, for example from a weak battery or a jump start, place additional strain on the electronics.

How can you tell that the 8U0959655C is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, an error message appears in the instrument cluster, and the diagnostic tool gets no connection to the control unit. A fault memory that cannot be cleared is a further sign. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

The warning light indicates the fault, so every message deserves attention.

If messages recur, have the system checked. If there is no connection to the diagnostic tool, the cause may equally lie in the wiring or the power supply.

Which vehicles is the 8U0959655C fitted in?

The control unit 8U0959655C is fitted in these vehicles: Audi Q3 8U (2011-2014) and 8U Facelift (2014-2018).

The overview shows which vehicles the unit is intended for.

• Audi Q3 8U (2011-2014)
• Audi Q3 8U Facelift (2014-2018)

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit. Only the fault memory read out beforehand shows whether the control unit is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 8U0 959 655D, 8U0959655, 8U0959655A, 8U0959655B, 8UD 959 655 A.

How does the repair of the 8U0959655C work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only afterwards remove the control unit 8U0959655C. Then create a repair order online and send in the unit, well packed.

Airbag24 checks the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. Processing usually takes 3–4 working days.

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 8U0959655C get to Airbag24?

You can send the control unit 8U0959655C in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

The printed repair order belongs in the parcel, and the unit must be packed to be shock-resistant.