Airbag control unit with part number 89170-48A20

What does the airbag control unit 89170-48A20 do?

In the Lexus the airbag control unit 89170-48A20 takes over control of the restraint system (SRS). It processes the signals from the crash sensors and, in an accident, triggers the appropriate airbags and seatbelt pretensioners within milliseconds. It also monitors the system continuously and reports faults via the airbag warning light.

The sensor readings are read in continuously. The unit processes them in the background while the vehicle is in operation.

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

Why does the control unit 89170-48A20 fail?

The most common cause is crash data stored after an accident, even if no airbag has triggered; a standard diagnostic tool cannot erase them. Aged components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes are also possible.

Airbag24 erases the crash data during the repair. The other causes include in detail:

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

These causes affect the electronics in different ways, which is why the check covers all areas.

How can you tell that the 89170-48A20 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently once the system has detected a fault. A fault message in the instrument cluster may appear alongside it.

A diagnostic tool that cannot establish a connection to the control unit, or a fault memory that cannot be cleared, are further signs of a fault.

In such a state, airbags and seatbelt pretensioners may possibly fail to deploy in an emergency. The display therefore deserves a prompt check.

Which vehicles is the 89170-48A20 fitted in?

The airbag control unit 89170-48A20 is fitted in these vehicles: Lexus RX AL20 (2015-2019).

The following list shows the vehicles that are recorded for this part number with us.

• Lexus RX AL20 (2015-2019)

First compare the part number on the label of the removed unit with this page. This makes sure that it is the right unit. Also have the fault memory read out beforehand, because only this result 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 89170-0E021, 89170-48210, 89170-48211, 891700000000000016768827392, 89170000000000005112856576.

How does the repair of the 89170-48A20 work?

First, have the fault memory read out and enclose the log. Then disconnect the battery; only after that remove the control unit. Then create the repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Processing usually takes 3–4 working days. Afterwards your own unit is 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 89170-48A20 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an additional charge. After the repair, Airbag24 sends it back by UPS.

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