Airbag control unit with part number 98221SJ120

What does the airbag control unit 98221SJ120 do?

The airbag control unit 98221SJ120 belongs to the restraint system (SRS) of Subaru. It assesses the crash sensor signals, decides in a crash within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system during operation.

The unit reports faults via the airbag warning light and records them in the fault memory. This allows the state of the system to be checked in a targeted way later on.

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

Why does the control unit 98221SJ120 fail?

Stored crash data after an accident is the most common cause, even if no airbag has been triggered; a normal diagnostic tool cannot erase it. Other possible causes include ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data remains in the unit until it is removed during the repair. It is therefore present even if the vehicle appears unremarkable after the event.

The other causes act over a longer period. Corrosion and damp contacts disrupt signal transmission, and voltage spikes can damage components.

How can you tell that the 98221SJ120 is defective?

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

The airbag warning light is the first sign to watch for. If it does not go out after the ignition is switched on, or lights up while driving, have the system checked promptly.

A lack of connection to the diagnostic tool is also a warning sign.

Which vehicles is the 98221SJ120 fitted in?

The airbag control unit 98221SJ120 is fitted in these vehicles: Subaru Forester SK (2018-2021) and SK Facelift (from 2021).

This list shows the vehicles for which the unit is intended.

• Subaru Forester SK (2018-2021)
• Subaru Forester SK Facelift (from 2021)

Comparing the part number on the label with this page ensures that you remove the right unit. Whether the control unit itself is defective, or a plug or cable is the cause, only the read-out fault memory will show.

For the same vehicles, we also repair control units with the part numbers 1523004370, 98221FC210, 98221SJ000, 98221SJ001.

How does the repair of the 98221SJ120 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only afterwards remove the control unit. Online, you create a repair order and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days.

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

The stated time refers solely to the work at Airbag24, not to your steps or to shipping.

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 98221SJ120 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 to you by UPS.

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