Airbag control unit with part number A2079010300

What does the airbag control unit A2079010300 do?

The airbag control unit A2079010300 is the central switching unit of the restraint system (SRS) at Mercedes-Benz. From the signals of the crash sensors it calculates whether a collision requires the airbags and seatbelt pretensioners to be triggered, and it monitors the entire system while doing so.

It detects a fault during operation, stores it and shows it via the airbag warning light in the instrument cluster.

After a collision it writes crash data and locks itself.

Why does the control unit A2079010300 fail?

The most common trigger is a crash data entry from a collision, even without a deployed airbag. On the A2079010300, aged electronic components, moisture and corrosion at connectors, and voltage spikes also contribute.

Crash data remains stored in the control unit, and a normal diagnostic tool does not erase it. That is exactly why the entry is significant for fault finding.

The other causes involve components that wear out over time, contacts that do not tolerate moisture, and voltage fluctuations in the vehicle electrical system.

How can you tell that the A2079010300 is defective?

A defect in the A2079010300 becomes visible through the airbag warning light in the instrument cluster, which lights up permanently or intermittently. In addition there are fault messages in the instrument cluster, the diagnostic tool cannot reach the control unit, and a fault memory cannot be cleared.

With such a finding, the airbags and seatbelt pretensioners may not be able to deploy in an emergency. The warning therefore requires a prompt check.

The warning alone does not give the cause. Only evaluating the fault memory shows whether the control unit or a cable is affected.

Which vehicles is the A2079010300 fitted in?

The A2079010300 is fitted in these vehicles: Mercedes-Benz E-Class C207 Coupé (2009-2016) and A207 Convertible (2010-2017).

The list below shows the vehicles for this part number.

• Mercedes-Benz E-Class C207 Coupé (2009-2016)
• Mercedes-Benz E-Class A207 Convertible (2010-2017)

First compare the part number on the label of the removed unit with this page. This ensures that you have the correct unit. Independently of that, have the fault memory read out, because this log shows whether the control unit itself is defective or a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 2079011700, A2078203226, A2079010100, A212 901 85 08.

How does the repair of the A2079010300 work?

First have the fault memory read out and attach the log. Then disconnect the battery and remove the control unit A2079010300. Create the repair order online before you send the well-packed unit in. At Airbag24 processing usually takes 3–4 working days.

At the Airbag24 premises the test bench checks the unit, defective components are repaired, the crash data is erased and a function test concludes the work. 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 A2079010300 get to Airbag24?

You send the control unit A2079010300 as a parcel, or you book a UPS collection for an extra charge. After the repair Airbag24 sends it back to you by UPS.

Pack the unit shock-proof and enclose the printed repair order in the parcel.