Airbag control unit with part number 9638904280

What does the airbag control unit 9638904280 do?

The control unit 9638904280 regulates the triggering of the restraint system (SRS) in the vehicle of Citroën. It processes the measured values from the crash sensors, and in an accident it decides within milliseconds which airbags and seatbelt pretensioners fire. It reports faults via the airbag warning light.

In normal operation the unit runs unobtrusively in the background, checking the sensors and wiring.

After an accident it stores crash data and locks itself.

Why does the control unit 9638904280 fail?

The most common cause on the 9638904280 is crash data from an accident, even if no airbag has deployed. Beyond that, components age, solder joints can go cold, and moisture or corrosion attack plug connections.

Crash data cannot be removed with a normal diagnostic tool. Airbag24 takes care of this during the repair.

Voltage spikes also count among the causes. They arise, for example, when the battery is weak or the vehicle is started with a jump start.

How can you tell that the 9638904280 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently when something is wrong with the 9638904280. In addition there may be an error message in the instrument cluster, no connection to the diagnostic tool, or a fault memory that cannot be erased.

While this fault persists, airbags and seatbelt pretensioners may not deploy in an emergency. For this reason the indication deserves prompt attention.

Have the finding clarified promptly, before you continue to use the vehicle.

Which vehicles is the 9638904280 fitted in?

The 9638904280 is fitted in these vehicles: Citroën Xsara I Facelift (2000-2006) and I (1997-2000).

The following vehicles are on record for this part number:

• Citroën Xsara I Facelift (2000-2006)
• Citroën Xsara I (1997-2000)

Comparing the part number on the label with this page only ensures that the unit removed is the right one. Have the fault memory read out beforehand, because only this result shows whether the control unit is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 550535300, 550741100, 550776300, 9633504180, 9633621380, 9638101980.

How does the repair of the 9638904280 work?

First have the fault memory read out and attach the log. Then disconnect the battery, remove the control unit 9638904280 and create a repair order online. Processing at Airbag24 usually takes 3–4 working days.

Then send the unit in well packed.

Airbag24 checks the unit on the test bench, replaces defective components and erases stored crash data. A function test concludes the work, after which your own unit comes back.

The sequence serves protection during all work on the removal.

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 9638904280 get to Airbag24?

You send the control unit 9638904280 to Airbag24 as a parcel, or you have it collected by UPS for an extra charge. It also comes back by UPS after the repair.

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