Airbag control unit with part number A2229004712

What does the airbag control unit A2229004712 do?

The airbag control unit A2229004712 is the central control unit of the restraint system for the Mercedes-Benz. It processes the signals of the crash sensors and, in an accident, decides which airbags and seatbelt pretensioners are triggered.

The decision is made within milliseconds. The unit also monitors the system continuously and reports faults via the airbag warning light.

After an accident, it stores crash data and remains locked. Only the repair lifts the lock.

Why does the control unit A2229004712 fail?

Causes of a failure include crash data stored after an accident, even if no airbag has been triggered. A standard diagnostic tool cannot erase this data.

Airbag24 erases the crash data during the repair, so that the cause is eliminated.

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.

How can you tell that the A2229004712 is defective?

The airbag warning light in the instrument cluster stays on constantly or intermittently and thus indicates a fault.

Error messages may also appear in the instrument cluster. If the diagnostic tool does not connect to the control unit, or the fault memory cannot be cleared, this likewise points to a defect. In this state, the airbags and seatbelt pretensioners may fail to deploy in an emergency.

Which vehicles is the A2229004712 fitted in?

The control unit A2229004712 is fitted in these vehicles: Mercedes-Benz S-Class W222 Saloon (2013-2020).

The list shows the vehicles recorded for this part number:

• Mercedes-Benz S-Class W222 Saloon (2013-2020)

Have the fault memory read out before removing the control unit. Only then does it become clear whether the unit itself is defective or whether a cable or plug is causing the fault. Afterwards, compare the part number on the label with this page.

For the same vehicles, we also repair control units with the part numbers A2229000303, A2229009908, A2229012601, A2229013503, A2229024709.

How does the repair of the A2229004712 work?

First you read out the fault memory and attach the log. Then you disconnect the battery, remove the control unit A2229004712, create the repair order online and send it in well packed.

At Airbag24, the unit is checked on the test bench, defective components are replaced, the crash data is erased and a function test is carried out. Checking, repairing and testing normally take 3–4 working days there.

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 A2229004712 get to Airbag24?

You send the control unit A2229004712 to Airbag24 as a parcel or book a UPS collection. After the repair, Airbag24 returns it to you by UPS.

Place the printed repair order in the parcel. Pack the unit shock-proof so that it arrives undamaged.