Airbag control unit with part number 98221AL01B

What does the airbag control unit 98221AL01B do?

In the Subaru vehicle, the airbag control unit 98221AL01B takes over control of the SRS restraint system. It receives the signals from the crash sensors, determines within milliseconds in a collision which airbags and seatbelt pretensioners are to deploy, and checks the entire system. Any faults that occur are reported to the airbag warning light.

The crash sensors are distributed throughout the vehicle and continuously supply values to the central unit in the control unit.

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

Why does the control unit 98221AL01B fail?

Stored crash data after an accident is the most common cause, even if no airbag has deployed. A normal diagnostic tool cannot erase it. Aged components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes are also possible causes.

The crash data are held in the memory of the control unit. Whether they are stored does not depend on whether an airbag was triggered.

Aged electronics form a separate focus. Components lose reliability over time, and solder joints can have gone cold without any visible sign.

Moisture and corrosion at plug connections disrupt signal transmission. Voltage spikes, for example from a weak battery or jump starting, put strain on the circuit.

How can you tell that the 98221AL01B is defective?

Typical signs are an airbag warning light that stays on or flashes intermittently, error messages in the instrument cluster, and a diagnostic tool with no connection. The fault memory also cannot be cleared.

• The airbag warning light in the instrument cluster flashes or stays on.
• An error message appears in the instrument cluster.
• The diagnostic tool establishes no connection to the control unit.
• The fault memory remains even after an attempt to clear it.

In an emergency, airbags and seatbelt pretensioners may not be able to deploy if there is a defect, so the warning must be taken seriously.

The warning light shows the defect as soon as the control unit detects it. However, a disrupted connection can also be caused by wiring.

Which vehicles is the 98221AL01B fitted in?

The 98221AL01B is fitted in these vehicles: Subaru Legacy BN (2014-2017), BN Facelift (2017-2020), BS (2014-2017) and BS Facelift (2017-2020); Subaru Outback BS Facelift (2018-2021) and BS (2015-2018).

The vehicles to which this part number belongs are listed here:

• Subaru Legacy BN (2014-2017)
• Subaru Legacy BN Facelift (2017-2020)
• Subaru Legacy BS (2014-2017)
• Subaru Legacy BS Facelift (2017-2020)
• Subaru Outback BS Facelift (2018-2021)
• Subaru Outback BS (2015-2018)

First compare the part number on the label of your removed unit with this page. This only confirms that it is the right unit. In addition, have the fault memory read out beforehand. Only this log shows whether the control unit is defective or whether a wire or plug is the cause.

For the same vehicles, we also repair control units with the part numbers 98221AL07A, 98221AN00A, 98221AN00E, 98221AN01A, 98221AN01D, 98221AN10A.

How does the repair of the 98221AL01B work?

First have the fault memory read out, then disconnect the battery. Only then remove the control unit. Next, create a repair order online and send in the well-packed unit together with the log.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and runs a function test. Airbag24 generally needs 3–4 working days for this. The unit is then returned 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 98221AL01B get to Airbag24?

You send the unit as a parcel or have it collected by UPS for an extra charge. Airbag24 returns it to you by UPS after the repair.

Please enclose the printed repair order and pack the unit shockproof.