Airbag control unit with part number 89170-48A81

What does the airbag control unit 89170-48A81 do?

The airbag control unit 89170-48A81 is the SRS control unit for Lexus. It checks the crash sensors, the wiring and the trigger circuits without pause, decides in a collision within milliseconds about airbags and seatbelt pretensioners, and reports faults to the airbag warning light.

The unit works in the background for as long as the vehicle is in operation. If it finds a deviation, it creates an entry in the fault memory.

After an accident, the unit writes crash data and locks itself. The lock only ends with the repair.

Why does the control unit 89170-48A81 fail?

The most common cause: crash data stored after an accident, even if no airbag fired. A normal diagnostic tool cannot delete it. Other causes are aged components, moisture and corrosion on plug connections, and voltage spikes.

The further causes at a glance:

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

Crash data remains stored even if the airbags did not trigger.

How can you tell that the 89170-48A81 is defective?

Typical signs are warnings in the instrument cluster: the airbag warning light stays on permanently or intermittently, and an error message is displayed. In addition, the diagnostic tool may be unable to connect to the control unit, and the fault memory cannot be cleared.

Typical signs at a glance:

• airbag warning light on, permanently or intermittently
• error message in the instrument cluster
• no connection between diagnostic tool and control unit
• fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may fail to trigger. As soon as you notice these signs, have them clarified promptly.

Which vehicles is the 89170-48A81 fitted in?

The 89170-48A81 is fitted in these vehicles: Lexus RX AL20 Facelift (2019-2022) and AL20 (2015-2019). The details apply to Lexus.

The vehicles appear in this list:

• Lexus RX AL20 Facelift (2019-2022)
• Lexus RX AL20 (2015-2019)

On the one hand, compare the part number on the label of the removed unit with this page. This only ensures that it is the right unit. On the other hand, have the fault memory read out beforehand, because only this result shows whether the control unit is defective or whether a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 89170-0E021, 89170-0E260, 89170-48490, 89170-48890, 89170-48A00, 89170-48A10.

How does the repair of the 89170-48A81 work?

First have the fault memory read out and attach the log, then disconnect the battery and only then remove the control unit. Afterwards, you create a repair order online and send in the well-packed unit. At Airbag24, processing usually takes 3–4 working days.

At Airbag24 the unit is checked on the test bench, defective components are replaced, stored crash data is deleted and a final test is carried out. Then your unit is sent 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 89170-48A81 get to Airbag24?

You take care of the shipping: you hand in the control unit as a parcel, or book a UPS collection for an extra charge. The return after the repair is made by UPS.

The repair order you print goes into the parcel. Pack the unit so that it is shock-resistant.