Airbag control unit with part number 89170-76400

What does the airbag control unit 89170-76400 do?

The unit 89170-76400 controls the restraint system (SRS) of Lexus as the airbag control unit. From the signals of the crash sensors it calculates, within milliseconds, which airbags and seatbelt pretensioners must be triggered in a crash. After an accident it stores crash data and locks itself.

During operation the control unit checks whether sensors, seatbelt pretensioners and airbag output stages are correctly connected and working. Every deviation is recorded in the fault memory and shown in the instrument cluster.

The memory belongs to diagnosis, because without it causes cannot be narrowed down.

Why does the control unit 89170-76400 fail?

The most common cause is crash data that remained in memory after an accident, even if no airbag triggered. A standard diagnostic tool cannot erase it. General influences such as ageing, moisture and voltage spikes are added.

Airbag24 deliberately removes this data during the repair so that the cause is eliminated.

The other causes show up in operation: electronic components age, solder joints can go cold, and moisture settles in the plugs. Voltage spikes occur, for example, with a weak battery or when a jump start is connected.

How can you tell that the 89170-76400 is defective?

The airbag warning light in the instrument cluster lights up permanently or only intermittently, or an error message appears there. The diagnostic tool then cannot find the control unit, and the fault memory cannot be emptied.

In this case airbags and seatbelt pretensioners may not trigger in a crash, regardless of how the vehicle otherwise runs.

The light alone does not show the cause. For this reason, have the fault memory read out before taking further steps.

Which vehicles is the 89170-76400 fitted in?

The control unit 89170-76400 is fitted in these vehicles: Lexus UX MZAA10 (from 2018). The information is based on the data we hold for this unit.

The overview shows the models in our records:

• Lexus UX MZAA10 (from 2018)

Compare the part number on the label of the removed unit with this page, so that you can be sure it is the right unit. Have the fault memory read out beforehand, because only the log shows whether the control unit or a plug or cable is the cause.

How does the repair of the 89170-76400 work?

First read out the fault memory and enclose the log. Then disconnect the battery; only after that remove the control unit. Next create a repair order online and send in the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, erases the crash data and carries out a function test.

This period covers only checking, repairing and testing. Finally your own unit goes 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 89170-76400 get to Airbag24?

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

Put the printed repair order in the parcel and pack the control unit shockproof.