Airbag control unit with part number 4M0959655AM

What does the airbag control unit 4M0959655AM do?

The airbag control unit 4M0959655AM is the central control unit of the restraint system (SRS) for Audi. It evaluates sensor signals, decides in the event of an accident within milliseconds whether airbags and seatbelt pretensioners fire, and monitors the system continuously. After an accident it stores crash data and locks itself.

It indicates faults in the system via the airbag warning light in the instrument cluster.

The control unit constantly checks its connections in the background.

Why does the control unit 4M0959655AM fail?

Most common cause: crash data stored after an accident, even if no airbag has fired. With this control unit, erasing the crash data is often not possible; if you would like the data erased, contact Airbag24 briefly before sending the unit in.

• Aged electronic components
• Cold solder joints
• Moisture and corrosion on plug connections
• Voltage spikes, for example from a weak battery or a jump-start

An accident leaves entries in the control unit, even if no airbag has fired. A normal diagnostic tool cannot erase them.

Which cause applies in an individual case is only determined by reading out the fault memory together with an inspection.

How can you tell that the 4M0959655AM is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently. In addition there are fault messages in the instrument cluster, a missing connection to the diagnostic tool and a fault memory that cannot be cleared.

Then airbags and seatbelt pretensioners may not be able to trigger in an emergency.

The light reports the defect itself; you do not have to search for it first. The cause is not yet named by it, though.

Which vehicles is the 4M0959655AM fitted in?

The 4M0959655AM is fitted in these vehicles: Audi Q7 4M (2015-2019) and 4M Facelift (2019-2024); Audi SQ7 4M (2016-2019) and 4M Facelift (from 2019).

The following list shows the vehicles that belong to this part number:

• Audi Q7 4M (2015-2019)
• Audi Q7 4M Facelift (2019-2024)
• Audi SQ7 4M (2016-2019)
• Audi SQ7 4M Facelift (from 2019)

Compare the part number on the label of the removed unit with this page. This only confirms that you have the right unit. Have the fault memory read out beforehand, because only that 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 4KE959655B, 4KE959655J, 4KE959655L, 4M0 959 655 AF, 4M0 959 655 G, 4M0 959 655 K.

How does the repair of the 4M0959655AM work?

First have the fault memory read out and attach the log, then disconnect the battery. Only after that remove the control unit and create a repair order online. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, repairs defective components and carries out a function test. The repair of the defect is not affected by this. Afterwards the unit goes back to you.

If you want the crash data erased, contact Airbag24 briefly before sending the unit in.

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 4M0959655AM get to Airbag24?

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

The printed repair order belongs in the parcel, and the unit must be packed shock-proof.