Airbag control unit with part number 3D0909601H

What does the airbag control unit 3D0909601H do?

The airbag control unit 3D0909601H is the central control unit of the restraint system (SRS) for Volkswagen. It evaluates crash sensors, decides within milliseconds in an accident which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After an accident it stores crash data and locks itself.

The manufacturer number Bosch 0285001858 is also printed on the housing. It helps to assign the unit, but says nothing about a defect.

If the control unit detects a deviation, it indicates this via the airbag warning light in the instrument cluster.

Why does the control unit 3D0909601H fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. An ordinary diagnostic tool cannot delete it; Airbag24 deletes it during the repair. Other causes are ageing components, cold solder joints, corrosion and moisture at plug connections, and voltage spikes.

The entry stays in the memory even if the airbags remained quiet during the accident.

Ageing and cold solder joints develop gradually. They show when contacts loosen or the circuit board no longer copes well with temperature changes.

Moisture and corrosion attack plug connections, and voltage spikes, for example from a weak battery or jump-starting, put additional strain on the electronics.

How can you tell that the 3D0909601H is defective?

An airbag warning light that stays on permanently or intermittently, an error message in the instrument cluster, a diagnostic tool without a connection to the control unit, and a fault memory that cannot be cleared indicate a defect. In that case, airbags and seatbelt pretensioners may possibly fail to deploy in an emergency.

The airbag warning light in the instrument cluster is the clearest sign. It shows that the system has detected a deviation, and with some faults it stays on permanently.

Even if the error message appears only briefly, it is a reason to have the system checked.

Which vehicles is the 3D0909601H fitted in?

The control unit 3D0909601H is fitted in these vehicles: Volkswagen Touareg 7L Facelift (2006-2010) and 7L (2002-2006).

The vehicles affected by this part number:

• Volkswagen Touareg 7L Facelift (2006-2010)
• Volkswagen Touareg 7L (2002-2006)

On the one hand, compare the part number on the label of the removed unit with this page. This only confirms that you have the right unit in front of you. On the other hand, have the fault memory read out before removal, because only this result 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 0 285 001 733, 0285001472, 3D0 909 601 D, 3D0 909 601 E, 3D0909601B, 3D0909601F.

How does the repair of the 3D0909601H work?

The process begins with reading out the fault memory, whose log goes into the parcel. Then you disconnect the battery, only then remove the control unit and create a repair order online. Finally, you send in the unit.

Airbag24 checks the unit you sent in on the test bench and repairs defective components. Airbag24 deletes stored crash data during this process, followed by a function test.

Processing at Airbag24 usually takes 3–4 working days. Afterwards, your own unit is returned. 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 3D0909601H get to Airbag24?

You send the control unit 3D0909601H as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

Put the printed repair order into the parcel and pack the unit shockproof.