Airbag control unit with part number A0285011109

What does the airbag control unit A0285011109 do?

The unit A0285011109 forms the restraint system (SRS) of Mercedes-Benz as a central unit. It processes the measured values from the crash sensors, decides in an accident within milliseconds on the triggering of airbags and seatbelt pretensioners, and monitors the entire system continuously. It indicates faults via the airbag warning light.

The system is designed so that the control unit checks at all times whether all connected components are performing their task. After an accident, it stores crash data and locks itself.

Why does the control unit A0285011109 fail?

The most common cause is crash data stored in the unit after an accident, even if no airbag was triggered; a normal diagnostic tool cannot erase it. In addition come aged electronic components, cold solder joints, moisture and corrosion on plug connectors, and voltage spikes, for example from a weak battery or a jump start.

Such crash data also arises from impacts in which no airbag fires. Airbag24 erases it during the repair.

Whether one of the further causes applies in an individual case is only clarified by the test on the test bench.

How can you tell that the A0285011109 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently. In addition, a fault message may appear in the instrument cluster, the diagnostic tool may find no connection to the control unit, or the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then not trigger.

The warning is therefore to be taken seriously. The warning light makes the finding visible as soon as the system detects it.

Which vehicles is the A0285011109 fitted in?

The A0285011109 is fitted in these vehicles: Mercedes-Benz Vito W447 (from 2014); Mercedes-Benz V-Class W447 (from 2014).

The overview of the models for which this part number is stored can be found here:

• Mercedes-Benz Vito W447 (from 2014)
• Mercedes-Benz V-Class W447 (from 2014)

First compare the part number on the label of the removed unit with this page. This ensures that the unit is the correct one. Also have the fault memory read out before removal, because only this log shows whether the control unit is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 4479006309, A 447 900 10 00, A4479000900, A4479010300.

How does the repair of the A0285011109 work?

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

Airbag24 checks the submitted unit on the test bench and fixes defective components. Stored crash data is erased, followed by a function test. Afterwards your own unit is returned to you.

Processing at Airbag24 usually takes 3–4 working days. This time applies only to checking, repairing and testing at Airbag24. 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 A0285011109 get to Airbag24?

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

Enclose the printed repair order in the package and pack the unit shockproof.