Airbag control unit with part number 9648403180

What does the airbag control unit 9648403180 do?

The airbag control unit 9648403180 is the central control unit of the restraint system (SRS) for Citroën. It evaluates the signals from the crash sensors, decides within a fraction of a second in an accident which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. If it detects a fault, it indicates this via the airbag warning light.

During operation the unit continuously checks the connected components and compares their signals with the target values. It stores any deviations in the fault memory so that they stand out during diagnosis.

After an accident the control unit stores crash data and locks itself.

Why does the control unit 9648403180 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered; a normal diagnostic tool cannot erase it. Airbag24 erases it during the repair. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data arise after accidents in which no airbag was triggered at all, and they remain in the memory until they are erased. A normal diagnostic tool does not remove them.

The other causes concern the electronics themselves. Aged components and cold solder joints lead to faults that sometimes only appear intermittently.

Moisture and corrosion at plug connections impair the contact. Voltage spikes, for example from a weak battery or a jump start, put additional stress on the circuitry.

How can you tell that the 9648403180 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and an error message appears. The diagnostic tool finds no connection to the control unit, or the fault memory cannot be erased. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The light is the clearest warning sign of the system. It indicates a detected fault even when nothing unusual is noticed while driving.

If the light flickers only now and then, have the fault memory read out. The entry stays stored even when the display goes out again.

Which vehicles is the 9648403180 fitted in?

The control unit 9648403180 is fitted in these vehicles: Citroën C5 I Facelift (2004-2008) and I (2001-2004).

The list shows the vehicles for which the unit is listed:

• Citroën C5 I Facelift (2004-2008)
• Citroën C5 I (2001-2004)

Compare the part number on the label of the removed unit with this page, so that you can be sure you have the right unit in front of you. Also have the fault memory read out, because only this 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 603481900, 9641968380, 9648665580, 9658177080, 9665558180.

How does the repair of the 9648403180 work?

First have the fault memory read out and enclose the log. Then disconnect the battery, remove the control unit, create a repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days; during this time Airbag24 tests the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test.

The order matters for your safety. Only once the battery is disconnected is the control unit removed.

After the function test your own unit is returned to you. The stated time applies exclusively to the work 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 9648403180 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back by UPS.

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