Airbag control unit with part number 5QS 959 655 A

What does the airbag control unit 5QS 959 655 A do?

The control unit 5QS 959 655 A is the link between the crash sensors and the airbags in the restraint system of Audi. In an accident, it decides within milliseconds which airbags and seatbelt pretensioners are triggered, and it continuously monitors the system.

The unit reports faults via the airbag warning light so that the driver recognises them.

After an accident, it stores crash data and locks itself.

Why does the control unit 5QS 959 655 A fail?

The most common cause is an entry of crash data after an accident, even if no airbag has triggered. This data cannot be removed with normal diagnostic tools. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, as well as voltage spikes.

The crash data remain in the memory after the vehicle has survived the accident. The unit keeps them, and a common diagnostic tool does not reach them. That is why the fault message remains.

Aged electronic components and cold solder joints are typical weak points. Moisture and corrosion attack the plug connections. Voltage spikes, for example from a weak battery or a jump start, place additional strain on the electronics.

Only the test on the test bench determines which cause is actually present.

How can you tell that the 5QS 959 655 A is defective?

A defect manifests mainly through the airbag warning light in the instrument cluster. In addition come a fault message, a missing connection to the diagnostic tool, and a fault memory that cannot be cleared.

If the warning light stays on permanently, this is a clear signal that something in the system is wrong. The same applies to a light that comes on only intermittently.

If the connection to the diagnostic tool fails, the memory cannot be read out. The cause then remains open for the time being.

In an emergency, airbags and seatbelt pretensioners may possibly fail to trigger as intended.

Which vehicles is the 5QS 959 655 A fitted in?

This control unit 5QS 959 655 A is fitted in these vehicles: Audi RS3 8YS Saloon (2021-2024).

The list is based on the information for this part number and contains the vehicles recorded for it. Here it is:

• Audi RS3 8YS Saloon (2021-2024)

Two steps will help you. Comparing the part number on the label with this page only ensures that you have removed the correct unit. In addition, have the fault memory read out beforehand, because only this result shows whether the control unit itself 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 5WA 959 655 G, 5WA959655J, 5WA959655L.

How does the repair of the 5QS 959 655 A work?

First read out the fault memory and keep the log, then disconnect the battery and remove the control unit. Afterwards, create a repair order online and pack the unit well. Airbag24 tests it, replaces defective components and tests the function. With this control unit, erasing the crash data is often not possible. If the crash data needs to be erased, please contact us briefly before sending the unit in – we will check your part number.

The sequence protects you while working on the vehicle, because the control unit may only be removed after the battery has been disconnected.

In the workshop of Airbag24, the unit is examined and repaired on the test bench. Airbag24 usually allows 3–4 working days for this. Your own unit is then returned 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 5QS 959 655 A get to Airbag24?

You can send the unit as a parcel or book a UPS collection for an extra charge. It goes back by UPS once the repair is complete.

The printed repair order goes into the parcel. The control unit must be packed shock-proof.