Airbag control unit with part number A2059014520

What does the airbag control unit A2059014520 do?

The airbag control unit A2059014520 controls the SRS in Mercedes-Benz vehicles. It checks sensors and connections continuously and, in an accident, decides within milliseconds whether airbags and seatbelt pretensioners are triggered. If a fault is detected, the airbag warning light in the instrument cluster lights up.

If an accident has occurred, the unit writes crash data to its memory and then locks itself.

During normal operation, monitoring runs in the background.

Why does the control unit A2059014520 fail?

Stored crash data most often leads to the failure of the A2059014520, even if no airbag has been deployed. A usual diagnostic tool cannot erase this data. Besides this, component ageing, cold solder joints, moisture and corrosion at plug connections, and voltage spikes play a role.

The memory records the event even when no airbags were triggered. On the electronics side, components age, and solder joints can become cold over time.

Moisture and corrosion attack mainly plug connections. Voltage spikes, for example from a weak battery or a jump start, can also lead to faults.

How can you tell that the A2059014520 is defective?

The airbag warning light in the instrument cluster shows a defect in the A2059014520 by staying on permanently or intermittently. In addition, there are fault messages in the instrument cluster, a fault memory that cannot be cleared, and no connection to the diagnostic tool.

Such signs mean that airbags and seatbelt pretensioners may not deploy in an emergency. Anyone who notices them should therefore have the system checked promptly.

Which vehicles is the A2059014520 fitted in?

First check whether your model is included. The control unit A2059014520 is fitted in these vehicles: Mercedes-Benz C-Class W205 Saloon (2014-2021) and S205 Estate (2014-2021).

The vehicles are listed here:

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

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit. Only the fault memory, once read out, shows whether the control unit is defective or whether a plug or cable is the cause. Have it read out 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 A2059014520 work?

First have the fault memory of the A2059014520 read out and enclose the log, then disconnect the battery. After that, remove the control unit, create a repair order online and send in the well-packed unit.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. After that, your own unit comes back to you.

Processing at Airbag24 usually takes 3–4 working days. 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 A2059014520 get to Airbag24?

You send the control unit A2059014520 to Airbag24 as a parcel or book a UPS collection for an extra charge. Return after the repair is made by UPS.

Put the printed repair order in the parcel and pack the unit shockproof.