Airbag control unit with part number 9804375780

What does the airbag control unit 9804375780 do?

The airbag control unit 9804375780 is the central control unit of the restraint system (SRS) for Citroën. It evaluates the signals from the crash sensors and decides in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered. It reports faults via the airbag warning light and monitors the system continuously; after an accident, it stores crash data and locks itself.

In doing so, it keeps watch over the sensors, airbags, seatbelt pretensioners and the cable connections. If it detects a deviation, it stores it in the fault memory.

Because it has to react in fractions of a second in an emergency, it checks itself continuously.

Why does the control unit 9804375780 fail?

With the 9804375780, the most common cause is crash data stored after an accident, even if no airbag has deployed. A normal diagnostic tool cannot erase them. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes, for example from a weak battery or a jump start.

The crash data comes first because it is the most common cause. It arises after an accident and remains stored in the unit.

The other causes concern components and connections. Electronics can age, solder joints can be cold, and moisture with corrosion attacks plug connectors.

Which cause applies only becomes clear when the fault memory is checked.

How can you tell that the 9804375780 is defective?

The airbag warning light on the instrument cluster lights up permanently or intermittently when there is a defect in the 9804375780. A fault message also appears on the instrument cluster, the diagnostic tool gets no connection to the control unit, and the fault memory cannot be cleared.

If the control unit is affected, airbags and seatbelt pretensioners may not deploy in an emergency. If the warning light is on, have the system checked.

A lit warning light is therefore a clear signal that the system has detected a fault.

Which vehicles is the 9804375780 fitted in?

A control unit is only fitted in certain vehicles. The 9804375780 is fitted in these vehicles: Citroën C-Elysée I (2012-2017) and I Facelift (from 2017).

Here are the vehicles in detail:

• Citroën C-Elysée I (2012-2017)
• Citroën C-Elysée I Facelift (from 2017)

To compare, proceed as follows: first compare the part number on the label of the removed unit with this page; this only ensures that it is the correct unit. Also have the fault memory read out beforehand, because only that shows whether the control unit is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 620595200, 98 043 759 80, 98 056 301 80.

How does the repair of the 9804375780 work?

For safety reasons, first have the fault memory read out and attach the log, before you disconnect the battery and only then remove control unit 9804375780. Then create a repair order online and send in the well-packed unit. Airbag24 checks it on the test bench, repairs the faults in the affected components, erases the stored crash data and carries out a function test.

Processing at Airbag24 usually takes 3–4 working days. Afterwards, your own, repaired unit is returned 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 9804375780 get to Airbag24?

You send control unit 9804375780 in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns your unit by UPS.

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