Airbag control unit with part number 89170-48D40

What does the airbag control unit 89170-48D40 do?

The airbag control unit 89170-48D40 coordinates the restraint system (SRS) in the vehicle for Lexus. It evaluates signals from the crash sensors and decides in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered. It monitors the entire system in the process.

The control unit shows faults via the airbag warning light, without you having to set anything.

After an accident, it stores crash data and locks itself.

Why does the control unit 89170-48D40 fail?

On the 89170-48D40, the most common cause is a crash data store left behind after an accident, even if no airbag has deployed; a normal diagnostic tool cannot erase this data. Aged electronic components, cold solder joints, moisture and corrosion on the plug connectors, and voltage spikes are also possible causes.

Voltage spikes arise, for example, from a weak battery or a jump start, and can stress the electronics. Moisture and corrosion mainly attack the plug connectors through which the unit is connected to the vehicle.

Whether any of these causes is actually present is only clarified by examining the unit.

How can you tell that the 89170-48D40 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently. A fault message in the instrument cluster accompanies it, the diagnostic tool gets no connection to the control unit, or the fault memory cannot be cleared.

This warning light is the sign to watch for, because airbags and seatbelt pretensioners may not be able to deploy in an emergency as long as the fault persists.

The display is therefore the reason to have the restraint system checked in good time.

Which vehicles is the 89170-48D40 fitted in?

The airbag control unit 89170-48D40 is fitted in these vehicles: Lexus RX AL20 Facelift (2019-2022) and AL20 (2015-2019).

Our data for this part number lists these vehicles:

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

Comparing the part number on the label of the removed unit with this page only ensures that you have the right unit. Also have the fault memory read out beforehand, because only this log shows whether the control unit is defective or a plug 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 89170-48D40 work?

With your 89170-48D40, first read out the fault memory and enclose the log. Then disconnect the battery and only then remove the control unit. Finally, create a 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 runs a function test. Afterwards the unit goes back to you.

The sequence is fixed for your safety, because the unit may only be removed once the battery is disconnected.

Processing at Airbag24 usually takes 3–4 working days. This time applies only to checking, repairing and testing there.

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 89170-48D40 get to Airbag24?

You send the control unit 89170-48D40 to Airbag24 as a parcel or book a UPS collection for an extra charge. UPS handles the return after the repair.

Put the printed repair order into the parcel and pack the unit shockproof.