Airbag control unit with part number P9472939

What does the airbag control unit P9472939 do?

The airbag control unit P9472939 is the control unit of the restraint system for Volvo. It evaluates the crash sensors, decides in a crash whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After a crash, it stores crash data and locks itself.

The housing also carries the number Bosch 0285001256. Messages from the control unit are shown via the airbag warning light in the instrument cluster.

The control unit works exclusively for this task, because in an emergency it must react immediately.

Why does the control unit P9472939 fail?

The most frequent trigger on the P9472939 is stored crash data after a crash, even without an airbag deployment. Further causes are aged components, cold solder joints, moisture or corrosion on plug connections, and voltage spikes.

A normal diagnostic tool cannot erase the crash data. At Airbag24, erasing it is part of the repair.

The other causes develop over the operating life, for example through ageing of the components and corrosion on contacts.

How can you tell that the P9472939 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently as soon as the P9472939 has a defect. Accompanying this, a fault message appears in the instrument cluster, there is no connection to the diagnostic tool, and a fault memory that cannot be cleared.

The light shows the state of the system. As long as the defect exists, airbags and seatbelt pretensioners may fail to deploy in an emergency.

Which vehicles is the P9472939 fitted in?

The control unit P9472939 is fitted in these vehicles: Volvo S80 TS (1998-2003) and TS Facelift (2003-2006).

The list below names the vehicles we have on record for this number.

• Volvo S80 TS (1998-2003)
• Volvo S80 TS Facelift (2003-2006)

Compare the number on the label of the removed unit with this page to confirm the correct unit. That comparison shows nothing more.

Also have the fault memory read out. Only this log shows whether the control unit is defective or whether a plug or cable is behind it.

For the same vehicles, we also repair control units with the part numbers 0 285 001 456, 285001254, 285001655, 30721921, 8622368, 8645271.

How does the repair of the P9472939 work?

First, have the fault memory read out and attach the log; then disconnect the battery and only afterwards remove the control unit. Next, create the repair order online, and then send in the packed unit. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 examines the unit on the test bench and eliminates the defects found. Afterwards, Airbag24 erases the stored crash data and runs a function test before your own unit comes back.

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 P9472939 get to Airbag24?

You send the control unit P9472939 as a parcel, or additionally book a UPS collection for an extra charge. Airbag24 sends the repaired unit back to you by UPS.

The printed repair order goes into the parcel; the unit must be packed to withstand impact.