Airbag control unit with part number A2059008818

What does the airbag control unit A2059008818 do?

The airbag control unit A2059008818 forms the central switching unit of the restraint system (SRS) in Mercedes-Benz. In an accident, it evaluates the sensor system and triggers the appropriate airbags and seatbelt pretensioners. It monitors the entire system at the same time.

Every fault detected is reported via the airbag warning light in the instrument cluster.

After an accident, it writes crash data and locks itself.

Why does the control unit A2059008818 fail?

The most common cause of the A2059008818 failing is that crash data was stored after an accident, even if no airbag was deployed. A normal diagnostic tool cannot erase it.

Crash data is also created when the airbags were not deployed, and a standard diagnostic tool cannot erase it. Besides this, causes from the electronics that develop over time come into question.

Electronics age, solder joints can go cold, and moisture or corrosion affect plug connections.

Voltage spikes, for example from a weak battery or from starting with an external power source, also count among the causes.

How can you tell that the A2059008818 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently on the A2059008818 and thus signals a fault. In addition come fault messages in the instrument cluster and a fault memory that cannot be cleared.

The diagnostic tool can also fail to establish a connection to the control unit. In this case, airbags and seatbelt pretensioners may not deploy in an emergency, which is why a check is advisable.

Which vehicles is the A2059008818 fitted in?

A look at the models tells you whether your car is affected. The control unit A2059008818 is fitted in these vehicles: Mercedes-Benz C-Class W205 Saloon (2014-2021) and S205 Estate (2014-2021).

The list of vehicles reads as follows:

• Mercedes-Benz C-Class W205 Saloon (2014-2021)
• Mercedes-Benz C-Class S205 Estate (2014-2021)

Comparing the part number on the label with this page confirms the right unit. Reading out the fault memory shows whether the control unit is defective or a plug or cable is the cause, and it therefore belongs before removal.

For the same vehicles, we also repair control units with the part numbers A 205 900 21 41, A205 900 18 14, A205 900 63 37, A205 900 95 27, A2059002512, A2059008618.

How does the repair of the A2059008818 work?

First have the fault memory of the A2059008818 read out and enclose the log, then disconnect the battery. Only then remove the control unit. Afterwards, create a repair order online, send in the unit, and Airbag24 needs 3–4 working days as a rule.

Airbag24 checks the unit on the test bench, repairs the defective components, erases 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 A2059008818 get to Airbag24?

You send the control unit A2059008818 as a parcel to Airbag24 or book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

The printed repair order goes into the parcel, and the unit must be packed shockproof.