Airbag control unit with part number 4F0959655A

What does the airbag control unit 4F0959655A do?

The airbag control unit 4F0959655A is the central control unit of the restraint system (SRS) for Audi. It evaluates the signals from the sensors, decides within milliseconds in an accident whether airbags and seatbelt pretensioners deploy, and reports faults via the airbag warning light.

The unit monitors the entire system continuously and checks the connected components for irregularities. The evaluation therefore does not only happen in an emergency, but during ongoing operation.

After an accident the unit stores crash data and locks itself. The lock is only lifted by the repair.

Why does the control unit 4F0959655A fail?

The most common cause in the 4F0959655A is the storage of crash data after an accident, even if no airbag has deployed. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

A normal diagnostic tool cannot erase this crash data. Airbag24 erases it during the repair.

The other causes concern the electronics themselves and their connections. A corroded plug or a cold solder joint can cause faults just as an aged component can.

How can you tell that the 4F0959655A is defective?

A defect in the 4F0959655A shows itself when the airbag warning light in the instrument cluster stays on continuously or intermittently, an error message appears, the diagnostic tool cannot connect to the control unit, or the fault memory cannot be cleared. In these cases airbags and seatbelt pretensioners may not be able to deploy in an emergency.

The light shows every fault the system itself detects. A defect is therefore displayed in the instrument cluster.

If the light appears while driving or stays on, it is worth having the fault memory read out. It then shows which fault the control unit has recorded.

Which vehicles is the 4F0959655A fitted in?

The airbag control unit 4F0959655A is fitted in these vehicles: Audi A6 C6 4F (2004-2008) and C6 4F Facelift (2008-2011).

The list shows the vehicles recorded for this part number.

• Audi A6 C6 4F (2004-2008)
• Audi A6 C6 4F Facelift (2008-2011)

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

For the same vehicles, we also repair control units with the part numbers 4F0 910 655 D, 4F0 910 655 Q, 4F0 959 655 B, 4F0 959 655 E, 4F0 959 655 G, 4F0910655B.

How does the repair of the 4F0959655A work?

First have the fault memory of the 4F0959655A read out and attach the log, then disconnect the battery and remove the control unit. Then create a repair order online and send the well-packed unit in. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, erases 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 4F0959655A get to Airbag24?

You send the unit as a parcel, or alternatively book a UPS collection for an extra charge. After the repair, Airbag24 sends the control unit 4F0959655A back by UPS.

The printed repair order goes into the parcel, and the packaging must be shock-resistant.