Airbag control unit with part number A2059012614

What does the airbag control unit A2059012614 do?

The airbag control unit A2059012614 is the central control unit of the SRS for Mercedes-Benz. It evaluates the signals from the crash sensors, determines in an emergency which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After an accident it stores crash data and locks itself.

It shows faults via the airbag warning light in the instrument cluster.

The triggering decision is made within fractions of a second, so the unit works in the background.

Why does the control unit A2059012614 fail?

Stored crash data is the most common cause with the A2059012614, even if no airbag has deployed, and a normal diagnostic tool cannot erase it. Ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes are also possible causes.

Crash data are entries in the memory and not component damage, so the workshop treats them separately.

The other causes concern components and connections in the electronics. Voltage spikes arise, for example, from a weak battery or from jump-starting.

How can you tell that the A2059012614 is defective?

The airbag warning light in the instrument cluster lights up on the A2059012614 permanently or intermittently, and a fault message appears in the instrument cluster as well. The diagnostic tool cannot connect to the control unit, and the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

The warning light alone does not say what the cause is; reading out the fault memory is needed for that.

Even a single sign is enough to have the system checked.

Which vehicles is the A2059012614 fitted in?

The A2059012614 is fitted in these vehicles: Mercedes-Benz C-Class W205 Saloon (2014-2021) and S205 Estate (2014-2021).

Here are the vehicles in which this part number occurs:

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

Compare the part number on the label of the removed unit with this page; that ensures you have the correct unit. Only reading out the fault memory answers whether the control unit is defective or whether a plug or cable is the cause, so have it done beforehand.

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 A2059012614 work?

First have the fault memory read out and attach the log; then disconnect the battery and remove the A2059012614. Then create a repair order online and send in the well-packed unit. Airbag24 generally needs 3–4 working days for checking, repairing and testing.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. Your own unit then comes 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 A2059012614 get to Airbag24?

You send the A2059012614 in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns your own unit to you by UPS.

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