Airbag control unit with part number 3F900-81R10

What does the airbag control unit 3F900-81R10 do?

The airbag control unit 3F900-81R10 is the central control unit of the SRS of Suzuki. It evaluates the crash sensors and decides in a collision, within milliseconds, which airbags and seatbelt pretensioners are triggered.

In addition, it monitors the system continuously and reports faults via the airbag warning light.

After an accident it stores crash data and locks itself. You should keep this in mind with every unit of this type.

Why does the control unit 3F900-81R10 fail?

Stored crash data after an accident are the most common cause, even if no airbag was deployed. Other causes are ageing electronics, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data remain stored in the unit, and a normal diagnostic tool does not remove them. The other causes sometimes only become noticeable over a longer period.

The further causes include, in detail:

• ageing electronic components
• cold solder joints
• moisture and corrosion at plug connections
• voltage spikes, for example from a weak battery or a jump start

How can you tell that the 3F900-81R10 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, and an error message appears. The diagnostic tool cannot connect to the control unit, and the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

The warning light shows every fault it detects. You should therefore take it seriously.

Which vehicles is the 3F900-81R10 fitted in?

The control unit 3F900-81R10 is fitted in these vehicles: Suzuki Swift RZ/AZ (2017-2020) and RZ/AZ Facelift (2020-2024).

You will find the vehicles on file in the list below.

• Suzuki Swift RZ/AZ (2017-2020)
• Suzuki Swift RZ/AZ Facelift (2020-2024)

Compare the part number on the label of the removed unit with this page. This only confirms that it is the right unit. Also have the fault memory read out beforehand, because only this log shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 38910-62J12-000, 38SC001R9RH.

How does the repair of the 3F900-81R10 work?

You have the fault memory read out and enclose the log. Then you disconnect the battery, remove the control unit and create a repair order online. Afterwards you send in the well-packed unit.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Afterwards the unit goes back to you.

Processing at Airbag24 usually takes 3–4 working days. 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 3F900-81R10 get to Airbag24?

You send the control unit 3F900-81R10 in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

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