Airbag control unit with part number 4KE 959 655 A

What does the airbag control unit 4KE 959 655 A do?

In the restraint system (SRS) of Audi, the airbag control unit 4KE 959 655 A evaluates the crash sensors. In an accident it decides within milliseconds which airbags and seatbelt pretensioners are triggered, and reports faults via the airbag warning light.

After an accident the device stores crash data and then locks its function. Only the repair lifts this lock.

In everyday use the system runs unnoticed in the background and continuously checks its components.

Why does the control unit 4KE 959 655 A fail?

On the 4KE 959 655 A the most common cause is crash data that remained stored after an accident, even if no airbag was triggered. Aged components, cold solder joints, moisture and corrosion on plugs, and voltage spikes are also possible causes.

Crash data are records that the device creates after a jolt. An ordinary diagnostic tool cannot erase them, so the fault persists even when the vehicle has long been running normally again.

The other causes act over a longer period. Components age, solder joints can become brittle over time, and moisture attacks plug connections. A weak battery or a jump start can also produce voltage spikes that stress the electronics.

How can you tell that the 4KE 959 655 A is defective?

On the 4KE 959 655 A you can recognise a defect from the airbag warning light in the instrument cluster, which lights up permanently or intermittently, from an error message in the instrument cluster, from no connection to the diagnostic tool, or from a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then not be able to trigger.

Typical signs at a glance:

• airbag warning light in the instrument cluster, permanently or intermittently
• error message in the instrument cluster
• diagnostic tool without connection to the control unit
• fault memory that cannot be cleared

If you notice any of these signs, a prompt check by a specialist workshop is worthwhile.

Which vehicles is the 4KE 959 655 A fitted in?

On Audi vehicles, the control unit 4KE 959 655 A is fitted in the following vehicles: Audi Q8 e-tron GE Sportback (2022-2024) and GE Facelift (2022-2025).

The allocation in detail:

• Audi Q8 e-tron GE Sportback (2022-2024)
• Audi Q8 e-tron GE Facelift (2022-2025)

Comparing the part number on the label of the removed unit with this page only confirms that you have the correct unit. Whether the control unit is defective or a plug or cable is the cause is shown only by the fault memory read out in advance.

For the same vehicles, we also repair control units with the part numbers 4KE959655J, 4M0 959 655 AF.

How does the repair of the 4KE 959 655 A work?

You first have the fault memory read out and enclose the log. Then disconnect the battery and remove the control unit 4KE 959 655 A. Next, create a repair order online and send the unit in well packed.

Airbag24 tests the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. After that the unit goes back to you.

At Airbag24 processing usually takes 3–4 working days. Only the time for testing, repairing and checking is meant.

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 4KE 959 655 A get to Airbag24?

You send the 4KE 959 655 A to Airbag24 as a parcel or book a UPS collection for an extra charge. Return shipment after the repair is made by UPS.

The printed repair order and a shock-proof packed unit belong in the parcel.