Airbag control unit with part number A9079004105

What does the airbag control unit A9079004105 do?

The airbag control unit A9079004105 is the central control unit for the restraint system of Mercedes-Benz. It processes the signals from the crash sensors and, in an accident, decides within fractions of a second which airbags and seatbelt pretensioners are triggered.

The manufacturer number Bosch 0285015383 is additionally printed on the housing.

The control unit monitors the system continuously and displays faults via the airbag warning light. After an accident it stores crash data and locks itself.

Why does the control unit A9079004105 fail?

Stored crash data after an accident is the most common cause, even if no airbag has deployed, and a normal diagnostic tool cannot erase it. Aged electronic components, cold solder joints, moisture and corrosion at plug connectors and voltage spikes can also cause a failure.

Crash data cannot be recognised from the outside, so a vehicle that looks unremarkable does not rule it out.

The other causes arise over the service life of the unit. Electronics age, solder joints can be cold, and moisture attacks the contacts. Voltage spikes, for example from a weak battery or a jump start, additionally stress the electronics.

How can you tell that the A9079004105 is defective?

The airbag warning light lights up permanently or intermittently, and a fault message appears in the instrument cluster. The diagnostic tool gets no connection to the control unit A9079004105, or the fault memory cannot be cleared. In that case the airbags and seatbelt pretensioners may not trigger in a crash.

The light shows the finding. A display in the instrument cluster is therefore not a side issue but a sign of a problem with the restraint system, which should be looked into promptly.

Which vehicles is the A9079004105 fitted in?

The control unit A9079004105 is fitted in these vehicles: Mercedes-Benz Sprinter W907 (from 2018).

The list of models follows:

• Mercedes-Benz Sprinter W907 (from 2018)

Compare the part number on the label of the removed unit with this page. This only tells you whether it is the right unit. Have the fault memory read out beforehand, because only this record shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 285010033, 285010349, 285011400, 285015024, A 907 900 48 07, A9079000304.

How does the repair of the A9079004105 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit A9079004105. Next, create a repair order online and send the unit off well packed.

At Airbag24 the unit is examined on the test bench, defective components are replaced, stored crash data is erased and a function test is carried out. Afterwards your own unit goes 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 A9079004105 get to Airbag24?

You send the control unit A9079004105 as a package or, for an extra charge, book a UPS collection. After the repair Airbag24 sends it back by UPS.

You enclose the printed repair order and pack the unit shock-proof.