Airbag control unit with part number 3F900-86R20

What does the airbag control unit 3F900-86R20 do?

The airbag control unit 3F900-86R20 belongs to the restraint system (SRS) of Suzuki. It evaluates the sensor signals in a collision, decides within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the entire system continuously.

It detects faults and reports them via the airbag warning light. After an accident, it stores crash data and locks itself; only the repair lifts this lock.

Why does the control unit 3F900-86R20 fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. A normal diagnostic tool does not erase it. Added to this are aged electronic components, cold solder joints, moisture or corrosion on plug connectors, and voltage spikes.

Airbag24 removes the crash data during the repair. The fault can first be narrowed down by reading out the fault memory.

The other causes concern ageing, connections and the power supply. Which of them applies is shown only by the evaluation of the fault memory.

How can you tell that the 3F900-86R20 is defective?

A defect shows up first as the airbag warning light in the instrument cluster, which lights up permanently or intermittently. Accompanying this are error messages or connection problems with the diagnostic tool.

• airbag warning light on permanently or intermittently
• error message in the instrument cluster
• no connection between diagnostic tool and control unit
• fault memory cannot be cleared

With these findings, airbags and seatbelt pretensioners may possibly not trigger in an emergency.

Whether the control unit is the cause is shown by the fault memory, not by a look at the instrument cluster.

Which vehicles is the 3F900-86R20 fitted in?

The control unit 3F900-86R20 is fitted in these vehicles: Suzuki Vitara LY and S. This information rests on the part number and not on an examination of your car.

The following list exists for this part number:

• Suzuki Vitara LY
• Suzuki Vitara S

Comparing the number on the label of the removed unit with this page shows whether it is the right unit, nothing more. Have the fault memory read out beforehand, because only the 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 16244579, 38910-54P00, 3891052D10, 3891065J50, 3891086R00, 3F900-76S00.

How does the repair of the 3F900-86R20 work?

At Airbag24, checking, repairing and testing take 3–4 working days as a rule. Your steps are: have the fault memory read out, disconnect the battery, then remove the control unit. Finally, create the repair order online and send the unit in.

At Airbag24 the unit is checked, damaged components are replaced, crash data is deleted, and then the function test follows. Afterwards your own unit comes back to you by UPS.

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 3F900-86R20 get to Airbag24?

You send the unit to us as a parcel, or alternatively book a UPS collection for an extra charge. Airbag24 takes care of the return by UPS after the repair.

The printed repair order goes into the parcel; pack the unit shock-proof.