Airbag control unit with part number 4F0 910 655 D

What does the airbag control unit 4F0 910 655 D do?

The airbag control unit 4F0 910 655 D is the central control unit of the restraint system (SRS) of Audi. It determines within milliseconds which airbags and seatbelt pretensioners are triggered, and it checks the system without interruption.

The sensors for impact and acceleration pass their measured values to the control unit. Based on these values it decides whether the restraint systems must be triggered.

If components report a fault, or the unit detects one itself, it stores it and shows it via the airbag warning light. After an accident, it also stores crash data and locks itself. This lock is lifted only by the repair.

Why does the control unit 4F0 910 655 D fail?

The most common cause of the 4F0 910 655 D is crash data after an accident, even if no airbag was triggered. Further causes are ageing components, cold solder joints, moisture and corrosion, and voltage spikes.

Crash data cannot be deleted with a normal diagnostic tool. Airbag24 removes it during the repair.

The individual causes are:

• Electronic components age and lose their reliability over time.
• Solder joints may have gone cold and lose their connection.
• Moisture and corrosion at plug connections impair the contact.
• Voltage spikes, for example from a weak battery or a jump start, stress the electronics.

How can you tell that the 4F0 910 655 D is defective?

The airbag warning light in the instrument cluster stays on constantly or intermittently, and an error message appears there. The diagnostic tool finds no connection to the 4F0 910 655 D, and the fault memory cannot be cleared.

The airbag warning light shows that something is wrong in the system. As long as it is lit, airbags and seatbelt pretensioners may not deploy in an emergency.

Even faults that occur only intermittently belong in the fault memory. Such findings should be checked promptly, not later.

Which vehicles is the 4F0 910 655 D fitted in?

This control unit is fitted in the following vehicles: Audi A6 C6 4F (2004-2008) and C6 4F Facelift (2008-2011); Audi S6 C6 (2006-2008) and C6 Facelift (2008-2010); Audi RS6 C6 (2008-2010).

The overview below lists the vehicles to which this part number is assigned.

• Audi A6 C6 4F (2004-2008)
• Audi A6 C6 4F Facelift (2008-2011)
• Audi S6 C6 (2006-2008)
• Audi S6 C6 Facelift (2008-2010)
• Audi RS6 C6 (2008-2010)

Compare the part number on the label of the removed unit with this page, so that you can be sure you have the correct unit. Have the fault memory read out beforehand; only its result shows whether the control unit is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 4F0 910 655 Q, 4F0 959 655 B, 4F0 959 655 E, 4F0 959 655 G, 4F0910655B, 4F0910655E.

How does the repair of the 4F0 910 655 D work?

Processing at Airbag24 usually takes 3–4 working days. Beforehand, read out the fault memory and enclose the log, then disconnect the battery before you remove the 4F0 910 655 D. Then create the repair order online and pack the unit well for dispatch.

Airbag24 checks the unit on the test bench, repairs defective components, deletes 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 4F0 910 655 D get to Airbag24?

You send the 4F0 910 655 D as a parcel or book a UPS collection for an extra charge. After the repair, UPS brings the unit back to you.

The printed repair order goes into the parcel. The unit is packed shockproof.