Airbag control unit with part number A2048709026

What does the airbag control unit A2048709026 do?

In the restraint system (SRS) for Mercedes-Benz, the airbag control unit A2048709026 takes over control. In an accident it decides which airbags and seatbelt pretensioners are triggered.

To do so it evaluates the signals of the crash sensors and acts within milliseconds. It monitors the entire system continuously and shows faults via the airbag warning light.

After an accident it stores crash data and locks itself. Without this control the restraint system would lack the basis for its decisions, which is why the unit runs constantly in operation.

Why does the control unit A2048709026 fail?

The most frequent cause for A2048709026 is crash data stored after an accident, even if no airbag has deployed. A normal diagnostic tool does not make these entries disappear. The following causes are also possible:

• aged components of the control electronics
• cold solder joints on the circuit board
• moisture and corrosion on the plugs
• voltage spikes, for example from a weak battery or jump-starting

Whether one of these causes applies can only be determined by checking. Only the check can clarify this.

How can you tell that the A2048709026 is defective?

The airbag warning light in the instrument cluster indicates a defect on the A2048709026 when it lights up permanently or intermittently. Fault messages in the instrument cluster are added.

If the diagnostic tool cannot connect to the control unit, or the fault memory cannot be cleared, a defect is also possible. These signs belong together and should be taken seriously.

In this state airbags and seatbelt pretensioners may not trigger in an emergency, so prompt clarification gives you safety.

Which vehicles is the A2048709026 fitted in?

The A2048709026 is fitted in these vehicles: Mercedes-Benz C-Class S204 Estate (2007-2014), W204 Saloon (2007-2014) and C204 Coupé (2011-2015).

The list below names the vehicles that Airbag24 has so far assigned to this part number.

• Mercedes-Benz C-Class S204 Estate (2007-2014)
• Mercedes-Benz C-Class W204 Saloon (2007-2014)
• Mercedes-Benz C-Class C204 Coupé (2011-2015)

Compare the number on the label of the removed control unit with this page, so that you can be sure you have the correct unit. Have the fault memory read out beforehand; the log shows whether the control unit itself is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 2048709426, 5WK44740, A204 870 68 26, A204 901 26 04, A204 901 35 02, A2048208285.

How does the repair of the A2048709026 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit A2048709026. Afterwards create a repair order online and send the well-packed unit in.

Airbag24 checks the unit, replaces defective components, deletes the crash data and runs a function test on the test bench. Processing usually takes 3–4 working days. After that your own unit goes back to you.

This order is binding for safety reasons. 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 A2048709026 get to Airbag24?

You send your control unit A2048709026 to Airbag24 as a parcel or book a UPS collection for an extra charge. The return after the repair is made by UPS.

A printed repair order goes into the parcel. Pack the unit so that it can be transported shock-proof.