Airbag control unit with part number 9803844280

What does the airbag control unit 9803844280 do?

The airbag control unit 9803844280 is the central control unit of the restraint system (SRS) for Citroën. It evaluates the signals from the crash sensors and, in an accident, decides within milliseconds on the triggering of airbags and seatbelt pretensioners. After an accident, it stores crash data and locks itself.

The control unit monitors the system continuously. It shows detected faults via the airbag warning light in the instrument cluster.

In everyday use the unit remains invisible, because it works in the background. Its task is the evaluation of the sensors and the control of the restraint devices.

Why does the control unit 9803844280 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered. Other causes are aged components, cold solder joints, moisture at plug connections and voltage spikes.

Crash data remains in the memory after an impact, regardless of whether an airbag was triggered. A normal diagnostic tool cannot remove it.

The other causes concern the electronics themselves and their connections. Ageing and moisture on the contacts act over time, and voltage spikes can accelerate them.

How can you tell that the 9803844280 is defective?

A defect shows on the airbag warning light in the instrument cluster, which lights up permanently or intermittently, and as a fault message in the instrument cluster. The diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared. Airbags and seatbelt pretensioners may then not trigger in an emergency.

The signs in detail:

• Airbag warning light in the instrument cluster, permanently or intermittently
• Fault message in the instrument cluster
• No connection between the diagnostic tool and the control unit
• Fault memory cannot be cleared

The warning light is the clearest sign the unit gives you. If you notice any of these signs, have the fault memory read out.

Which vehicles is the 9803844280 fitted in?

The control unit 9803844280 is fitted in these vehicles: Citroën C5 II 1st Facelift (2010-2012), II (2008-2010) and II 2nd Facelift (2012-2017). To match it with your car, use make, model and year of manufacture.

The list shows the vehicles in which this unit is fitted.

• Citroën C5 II 1st Facelift (2010-2012)
• Citroën C5 II (2008-2010)
• Citroën C5 II 2nd Facelift (2012-2017)

On the one hand, compare the part number on the label of the removed unit with this page to confirm the correct unit. On the other hand, have the fault memory read out beforehand. Only the result 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 9657456680, 9665266080, 9665558180, 9674290580.

How does the repair of the 9803844280 work?

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

The sequence is mandatory for safety reasons. Reading out comes before disconnecting, and disconnecting comes before removal.

Airbag24 tests the unit on the test bench, repairs defective components and carries out a function test. 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 9803844280 get to Airbag24?

You send the control unit 9803844280 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns your own unit by UPS.

Put the printed repair order into the parcel and pack the unit shock-proof.