Airbag control unit with part number 98221SJ100

What does the airbag control unit 98221SJ100 do?

The airbag control unit 98221SJ100 controls the restraint system (SRS) in vehicles from Subaru. It evaluates the signals from the crash sensors, determines within fractions of a second in an accident which airbags and seatbelt pretensioners are triggered, and monitors the system constantly. Faults that occur are shown via the airbag warning light.

During driving, the unit works in the background and checks the connected components. These include sensors, seatbelt pretensioners and airbags.

After an accident it stores crash data and locks itself. The lock is only lifted by the repair.

Why does the control unit 98221SJ100 fail?

The most common cause is stored crash data from an accident, even if no airbag has been triggered; a normal diagnostic tool cannot erase it. In addition, aged electronic components, cold solder joints, moisture, corrosion at plug connections and voltage spikes may be involved.

Stored crash data is the most common cause, because the unit records every impact it registers. This also applies when no airbag has been triggered and little damage is visible from outside. A normal diagnostic tool cannot remove these entries.

In addition, electronic components age, and solder joints on the circuit board can go cold and lose contact. Moisture and corrosion at the plug connections impair signal transmission.

Voltage spikes, for example from a weak battery or a jump start, put additional strain on the unit.

How can you tell that the 98221SJ100 is defective?

Signs are an airbag warning light that stays on permanently or intermittently, an error message in the instrument cluster, a diagnostic tool without connection, and a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

These signs are easy to observe in everyday use:

• Airbag warning light in the instrument cluster stays on permanently
• Airbag warning light stays on intermittently
• Error message in the instrument cluster
• Diagnostic tool finds no connection
• Fault memory cannot be cleared

If any of these signs appear, have the system checked promptly.

Which vehicles is the 98221SJ100 fitted in?

The airbag control unit 98221SJ100 is fitted in these vehicles: Subaru Forester SK (2018-2021) and SK Facelift (from 2021).

Here you can see the vehicles to which this part number is assigned:

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

Compare the part number on the label of the removed unit with this page, to make sure you have the right unit. Whether the control unit itself is defective or a plug or cable is the cause only becomes clear from the fault memory log read out beforehand.

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

How does the repair of the 98221SJ100 work?

Have the fault memory read out and attach the log. Then disconnect the battery and remove the control unit; afterwards create a repair order online and send in the unit well packed. Processing at Airbag24 usually takes 3–4 working days.

At Airbag24, the unit sent in is first checked on the test bench. Defective components are replaced, the stored crash data is erased and a function test is carried out.

Only then is the unit returned to you. The removal order must be observed for safety reasons.

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 98221SJ100 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge, and after the repair Airbag24 returns it by UPS.

Place the printed repair order in the parcel and pack the unit shock-proof.