Airbag control unit with part number 4M0959655P

What does the airbag control unit 4M0959655P do?

The airbag control unit 4M0959655P takes over the central control of the restraint system (SRS) in the vehicle from Audi. It evaluates the signals from the crash sensors, decides in an accident within milliseconds whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After an accident it stores crash data and locks itself.

The unit shows faults via the airbag warning light in the instrument cluster, so that you can react.

The crash data record what the control unit registered during the accident. They belong to the control unit itself and remain stored there.

Why does the control unit 4M0959655P fail?

The most common cause for control unit 4M0959655P is a storage of crash data after an accident, even if no airbag has deployed. Other possible causes are aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes.

Crash data cannot be erased with a normal diagnostic tool. Airbag24 erases it during the repair, so that it is no longer stored in the unit afterwards.

The other causes concern the electronics and their connections. Moisture and corrosion disturb the contact at plug connections, cold solder joints can cause loose contacts, and voltage spikes arise, for example, with a weak battery or when jump-starting.

How can you tell that the 4M0959655P is defective?

A defect in control unit 4M0959655P can be recognised by the airbag warning light in the instrument cluster, which lights up permanently or intermittently. In addition there is a fault message in the instrument cluster, a diagnostic tool with no connection to the control unit, and a fault memory that cannot be cleared.

In an emergency, airbags and seatbelt pretensioners may not be able to deploy because of such a defect. The warning light makes the fault clearly visible, which is why a prompt check is advisable.

Which vehicles is the 4M0959655P fitted in?

The vehicle registration document shows whether your model is one of those listed. The airbag control unit 4M0959655P 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 we have on record for this control unit.

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

Comparing the part number on the label of the removed unit with this page only confirms that it is the right control unit. Having the fault memory read out before you remove anything, on the other hand, 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 4KE959655B, 4KE959655J, 4KE959655L, 4M0 959 655 AF, 4M0 959 655 G, 4M0 959 655 K.

How does the repair of the 4M0959655P work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove control unit 4M0959655P. Then create a repair order online and send the unit in well packed. At Airbag24 processing usually takes 3–4 working days.

At Airbag24 the unit is checked on the test bench. Defective components are replaced, the stored crash data are erased and a function test is carried out. 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 4M0959655P get to Airbag24?

You send control unit 4M0959655P as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 returns the unit to you by UPS.

Put the printed repair order into the parcel and pad the unit so that it lies shockproof.