Airbag control unit with part number A9079004305

What does the airbag control unit A9079004305 do?

The airbag control unit A9079004305 decides in the restraint system (SRS) of Mercedes-Benz which airbags and seatbelt pretensioners are triggered in a crash. To do so, it evaluates the signals from the crash sensors and monitors the entire system. Reported faults are shown via the airbag warning light.

The control unit is active on every journey and checks connections and triggers continuously.

In addition, the unit carries the manufacturer number Bosch 0285015385. After an accident it stores crash data and locks itself.

Why does the control unit A9079004305 fail?

Stored crash data forms the most common cause, and this also applies without a deployed airbag. A standard diagnostic tool cannot clear it. Further causes are aged electronic components, cold solder joints, moisture and corrosion, and voltage spikes.

The crash data remains in the memory until it is cleared during the repair. Individual memory contents do not reveal whether an airbag has deployed.

Ageing, cold solder joints and moisture act on the circuit over the long term. Voltage spikes, for example from a jump-start or a weak battery, are also to be considered as a cause.

How can you tell that the A9079004305 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, a fault message appears, the diagnostic tool finds no connection to the control unit, or the fault memory cannot be cleared. In an emergency, the airbags and seatbelt pretensioners may then fail to deploy.

The light shows the defect, and its appearance must not be ignored. When it lights up, looking into the fault memory is worthwhile without delay.

Which vehicles is the A9079004305 fitted in?

The A9079004305 is fitted in these vehicles: Mercedes-Benz Sprinter W907 (from 2018). A comparison with your own vehicle provides certainty.

These vehicles are recorded in the assignment:

• Mercedes-Benz Sprinter W907 (from 2018)

Compare the part number on the label of the removed unit with this page; this only confirms the identity of the unit. Then have the fault memory read out, because the result shows whether the control unit is defective or whether a connector 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 A9079004305 work?

First, have the fault memory read out and enclose the log. Then disconnect the battery before you remove the control unit. Next, create the repair order online and send in the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

At Airbag24 the unit is checked, damaged parts are replaced and the stored crash data is cleared. A function test completes the work, after which your own unit returns 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 A9079004305 get to Airbag24?

You send the A9079004305 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

The printed repair order goes into the parcel, and the unit is packed shock-resistant.