Airbag control unit with part number A2079012700

What does the airbag control unit A2079012700 do?

The SRS control unit A2079012700 is the switching centre of the restraint system at Mercedes-Benz. It processes impact signals, determines the triggering of the airbags and seatbelt pretensioners, and monitors the system continuously during operation.

In operation, the unit checks its surroundings, that is the sensors, wiring and control circuits. It stores detected faults and shows them on the airbag warning light.

After an accident, the control unit keeps crash data and then locks itself.

Why does the control unit A2079012700 fail?

Crash data from an accident is the most common cause, even if no airbag has deployed, because an ordinary diagnostic tool cannot erase it. In addition come aged electronic components, cold solder joints, moisture and corrosion at plug connectors, as well as voltage spikes.

• aged electronic components
• cold solder joints
• moisture and corrosion at plug connectors
• voltage spikes, for example with a weak battery or a jump start

The crash data remains in the memory and is removed in a targeted way only during the repair, and Airbag24 carries this out in this step.

The other causes are wear and environmental influences. Which of them applies to your unit is shown only by the check.

How can you tell that the A2079012700 is defective?

Signs are an airbag warning light that stays on permanently or intermittently, error messages in the instrument cluster, no contact with the diagnostic tool, and a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

• Airbag warning light in the instrument cluster, on permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool receives no connection to the control unit
• Fault memory remains, even after clearing

The light shows that the system has detected a fault, and it should go out again after the ignition is switched on.

If the diagnostic tool cannot establish a connection, the control unit may be to blame, but so may wiring or the power supply. Therefore have the findings clarified by a check.

Which vehicles is the A2079012700 fitted in?

The SRS control unit A2079012700 from Mercedes-Benz is fitted in these vehicles: Mercedes-Benz E-Class C207 Coupé (2009-2016) and A207 Convertible (2010-2017). The stored assignment on this page is decisive.

The vehicles are listed as follows:

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

Compare the part number with this page using the label of the removed unit. This confirms that you have the right part, but it says nothing about its condition. Have the fault memory read out beforehand, because only its log shows whether the control unit or a plug 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 A2079012700 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Afterwards create the repair order online and send the well-packed unit. At Airbag24, checking, repairing and the function test usually take 3–4 working days.

On the test bench, Airbag24 examines the unit, replaces defective components, removes the crash data and carries out a function test. Afterwards your own unit is returned to you.

The order protects you during removal. The 3–4 working days cover only the work at Airbag24, not your steps beforehand. 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 A2079012700 get to Airbag24?

You send the control unit A2079012700 in a parcel or book a UPS collection. After the repair, UPS brings the unit back to you.

Enclose the printed repair order and pack the unit so that it is shock-resistant.