Airbag control unit with part number 8R0959655D

What does the airbag control unit 8R0959655D do?

The airbag control unit 8R0959655D coordinates the SRS restraint system of Audi. It evaluates the crash sensors, selects the appropriate airbags and seatbelt pretensioners in the event of an impact within milliseconds, and monitors the entire system. It passes faults on via the airbag warning light.

The control is designed for fractions of a second, because in an emergency there is no time for detours. At the same time it keeps an eye on the condition of the components so that a fault becomes visible as early as possible.

After an accident the unit stores crash data and locks itself. The workshop then reads out the fault memory first, because the first clues are stored there.

Why does the control unit 8R0959655D fail?

Most often this is due to crash data stored after an accident, even if no airbag was triggered; a normal diagnostic tool cannot remove it. Other causes include aged components, cold solder joints, moisture and corrosion on connectors, and voltage spikes.

In detail, these further causes come into consideration:

• aged electronic components
• cold solder joints
• moisture and corrosion at connectors
• voltage spikes, for example with a weak battery or after a jump start

Which of these applies in the specific case is shown by reading out the fault memory in combination with an examination of the unit.

How can you tell that the 8R0959655D is defective?

The airbag warning light in the instrument cluster lights up permanently or only intermittently, a fault message is displayed, the diagnostic tool cannot reach the control unit, and the fault memory cannot be reset. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The warning light is the first sign you notice in everyday use. A fault message in the instrument cluster is usually followed by a check at the workshop.

A fault is not always recognisable on the control unit itself, because cables can also be affected. Only the diagnosis therefore provides clarity.

Which vehicles is the 8R0959655D fitted in?

The 8R0959655D is fitted in these vehicles: Audi Q5 8R Facelift (2012-2017) and 8R (2008-2012). The assignment is sorted by part number and applies to the models stored.

The list below is compiled so that you can compare your vehicle directly:

• Audi Q5 8R Facelift (2012-2017)
• Audi Q5 8R (2008-2012)

Two steps prepare the repair. Compare the part number on the label of the removed unit with this page; then you only know that you have the right unit. Afterwards have the fault memory read out; only its contents show whether the control unit is defective or whether a connector or cable is affected.

For the same vehicles, we also repair control units with the part numbers 8R0 959 655 B, 8R0 959 655 G, 8R0959655F, 8R0959655H.

How does the repair of the 8R0959655D work?

First read out the fault memory and attach the log, then disconnect the battery and only then remove the control unit. With the online repair order you send in the packed unit. Airbag24 needs 3–4 working days in general for checking, repairing and testing.

At Airbag24 a test bench checks the unit, defective components are replaced, and the stored crash data is deleted. A function test follows, and the unit goes back to you.

Keep to these steps in this order, because the battery is already disconnected when the unit is removed.

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 8R0959655D get to Airbag24?

You send the unit as a parcel or arrange a UPS collection for an extra charge. Airbag24 also returns the unit by UPS after the repair.

Pack the printed repair order into the parcel and pack the unit shockproof.