Airbag control unit with part number 8L0 959 655

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

The airbag control unit 8L0 959 655 controls the restraint system (SRS) at Audi. It processes the signals from the crash sensors, decides in a crash which airbags and seatbelt pretensioners are triggered, and monitors the system continuously.

The number Bosch 0285001652 is an additional identifier on the housing, alongside the part number. If the unit detects a fault, it stores it in the fault memory and shows it via the airbag warning light.

It stores crash data from a collision, and then it locks itself.

Why does the control unit 8L0 959 655 fail?

Stored crash data from a collision is the most common cause on the 8L0 959 655, even if no airbag has deployed. Other causes include ageing components, moisture at the connectors and voltage spikes in the vehicle electrical system.

Crash data cannot be erased with a standard diagnostic tool. The entry therefore remains visible for every evaluation.

The other triggers are ageing electronics, moisture and corrosion, and brief voltage spikes, for example during jump-starting or with a weak battery. Which of these applies is only confirmed by the evaluation.

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

The airbag warning light in the instrument cluster lights up on the 8L0 959 655 permanently or only intermittently. There may also be a fault message in the instrument cluster, a diagnostic tool without a connection to the control unit, and a fault memory that cannot be cleared.

In this condition the airbags and seatbelt pretensioners may not be able to deploy in an emergency. The warning is therefore a reason to have it checked promptly.

The warning light does not show whether the control unit or the wiring is affected. Reading out the fault memory is required for that.

Which vehicles is the 8L0 959 655 fitted in?

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

The following list shows the vehicles in which this control unit is installed.

• 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 it is the correct unit. Have the fault memory read out as well, because only this log shows whether the control unit itself is defective or a connector 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 work?

First have the fault memory read out and attach the log. Then disconnect the battery and remove the control unit 8L0 959 655. Next, create the repair order online and send the unit in, well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 examines the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. Afterwards your own unit is 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 8L0 959 655 get to Airbag24?

Either you send the control unit 8L0 959 655 as a parcel to Airbag24, or you book a UPS collection for an extra charge. Airbag24 sends the unit back to you by UPS after the repair.

Pack the unit shock-proof and enclose the printed repair order.