Airbag control unit with part number A2229009517

What does the airbag control unit A2229009517 do?

The airbag control unit A2229009517 is the central control unit of the restraint system (SRS) in Mercedes-Benz vehicles. It evaluates the crash sensors, decides within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously.

During operation, it checks the connected components. If it finds a fault, it reports it via the airbag warning light in the instrument cluster.

After an accident, the control unit stores crash data and locks itself. Storing the data is part of the unit's function.

Why does the control unit A2229009517 fail?

Stored crash data is the most common cause, because it arises after an accident, even if no airbag has deployed. A normal diagnostic tool cannot clear it. This data stays in the unit until it is removed during the repair.

Beyond that, ageing electronic components, cold solder joints, moisture and corrosion at plug connections, or voltage spikes can impair the function. Voltage spikes arise, for example, from a weak battery or from jump-starting.

Which cause applies to a particular unit is shown by the examination on the test bench. Airbag24 deletes the crash data in the course of the repair.

How can you tell that the A2229009517 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, and a fault message may appear in addition. If the diagnostic tool cannot establish a connection to the control unit, or the fault memory cannot be cleared, that is an indication of a defect in the A2229009517.

In an emergency, airbags and seatbelt pretensioners may then fail to deploy. You should therefore have such signs checked promptly.

Which vehicles is the A2229009517 fitted in?

The A2229009517 is fitted in these vehicles: Mercedes-Benz S-Class W222 Saloon (2013-2020).

The following models are recorded for this part number:

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

Before removing the control unit, have the fault memory read out. This makes clear whether the control unit itself is defective or whether a plug or cable triggers the message. Compare the part number on the label with this page afterwards.

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

How does the repair of the A2229009517 work?

Processing at Airbag24 usually takes 3–4 working days. It covers checking, repairing and testing the unit.

You read out the fault memory and enclose the log. Then you disconnect the battery, remove the control unit and create the repair order online. The well-packed unit is sent in.

At Airbag24, the unit is first examined on the test bench. Defective components are replaced by the workshop, crash data is deleted, and a function test concludes the work. The unit then goes back 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 A2229009517 get to Airbag24?

You send the control unit as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

Place the printed repair order in the parcel and pack the unit shock-resistant.