Airbag control unit with part number 8L0 959 655 A

What does the airbag control unit 8L0 959 655 A do?

The airbag control unit 8L0 959 655 A is the central control unit of the restraint system (SRS) for Audi. It evaluates the signals from the impact sensors, decides in an emergency within milliseconds whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously. It reports faults via the airbag warning light.

While driving, the unit checks the entire chain of sensors, wiring and triggering elements. After an accident, it stores crash data and locks itself.

The control unit thereby connects the sensors with the triggering. Without a reliable evaluation, the protective effect of the overall system is limited.

Why does the control unit 8L0 959 655 A fail?

Stored crash data after an accident is the most common cause, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage peaks, for example from a weak battery or a jump start.

Airbag24 removes these crash data in the course of the repair. This is not reliably possible with common tools.

The other causes are linked to ageing, environmental influences and electrical loads. They do not always show up immediately but gradually.

How can you tell that the 8L0 959 655 A is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, an error message appears in the instrument cluster, the diagnostic tool gets no connection to the control unit, and the fault memory cannot be cleared. In this condition, airbags and seatbelt pretensioners may possibly fail to trigger in an emergency.

The light reports the finding itself and makes it visible as soon as the system detects a fault. A look at the instrument cluster after starting is therefore worthwhile.

If one of these signs appears, waiting brings no certainty. A prompt check will establish the condition of the restraint system.

Which vehicles is the 8L0 959 655 A fitted in?

The airbag control unit 8L0 959 655 A is fitted in these vehicles: Audi S3 8L (1999-2003); Audi A3 8L (1996-2000) and 8L Facelift (2000-2003).

The vehicles for which this unit is stored are shown in the overview below.

• Audi S3 8L (1999-2003)
• Audi A3 8L (1996-2000)
• Audi A3 8L Facelift (2000-2003)

Compare the part number on the label of the removed unit with this page; this only confirms that you have the right unit. Also have the fault memory read out beforehand, because only this result shows whether the control unit itself is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 0285001223, 0285001304, 0285001352, 1J0 909 601 A, 285001352, 8D0959655E.

How does the repair of the 8L0 959 655 A work?

First have the fault memory read out and attach the log; then disconnect the battery and only afterwards remove the control unit. Then create the repair order online and send in the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 tests the unit on the test bench and replaces defective components. It then erases the stored crash data and carries out a function test.

Your own, repaired unit then 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 8L0 959 655 A get to Airbag24?

You send the unit in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

Put the printed repair order into the parcel and pack the control unit shockproof.