Airbag control unit with part number 3F900-86RC0

What does the airbag control unit 3F900-86RC0 do?

The airbag control unit 3F900-86RC0 is the evaluation unit of the restraint system (SRS) for Suzuki. It measures the impact values via the crash sensors, decides on airbags and seatbelt pretensioners in an accident, and continuously checks itself. After an accident it stores crash data and locks itself.

The crash sensors supply the values, and the control unit makes the trigger decision within milliseconds. Detected faults are written to the fault memory and shown via the airbag warning light.

This function makes the unit a central part of passive safety in the vehicle.

Why does the control unit 3F900-86RC0 fail?

Stored crash data is considered the most common cause in the 3F900-86RC0, even when no airbag has deployed. Added to this are aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes from the vehicle electrical system.

A normal diagnostic tool cannot remove this data; Airbag24 does that during the repair.

The other causes lie in the electronics. Components age, solder joints go cold, and moisture has a corrosive effect on plug connectors. Voltage spikes, for example from a weak battery or a jump start, put additional strain on the unit.

How can you tell that the 3F900-86RC0 is defective?

A fault in the 3F900-86RC0 is first recognisable by the airbag warning light, which stays on constantly or intermittently. Fault messages may follow. The diagnostic tool finds no control unit, and the fault memory remains.

In the worst case, airbags and seatbelt pretensioners may therefore be unable to deploy. These signs point to a prompt check of the system.

Which vehicles is the 3F900-86RC0 fitted in?

The control unit 3F900-86RC0 is fitted in these vehicles: Suzuki Vitara LY and S.

The vehicles at a glance:

• Suzuki Vitara LY
• Suzuki Vitara S

Comparing the part number on the label with this page only ensures that the right unit is at hand. Have the fault memory read out beforehand; the result clarifies whether the control unit itself is defective or whether a plug or 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 3F900-86RC0 work?

First have the fault memory read out, then disconnect the battery and only afterwards remove the control unit. Create the repair order online, then pack the unit well and send it in. At Airbag24, processing usually takes 3–4 working days.

Airbag24 examines the unit on the test bench. Defective components are repaired, crash data is removed, and a function test completes the process. Afterwards your own unit goes back 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 3F900-86RC0 get to Airbag24?

You send the 3F900-86RC0 to Airbag24 by parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

Pack the control unit shockproof. The printed repair order belongs in the shipment.