Airbag control unit with part number 89170-42B80

What does the airbag control unit 89170-42B80 do?

The airbag control unit 89170-42B80 is the control unit of the SRS system, that is the restraint system, in Toyota. It assesses the messages from the crash sensors and determines within milliseconds which airbags and seatbelt pretensioners trigger in an accident. In addition, it checks the system continuously and shows faults via the airbag warning light.

The monitoring continues while driving. The unit checks its connections to the sensors and to the trigger circuits, without any intervention being necessary.

After an accident the control unit records crash data and locks itself.

Why does the control unit 89170-42B80 fail?

The most common cause is stored crash data from an earlier accident, even if no airbag has deployed, which cannot be removed with a standard diagnostic tool. Other causes include aged electronic components, cold solder joints, moisture at plug connectors and voltage spikes.

The memory holding the crash data remains in place. It is only erased during the repair at Airbag24.

For the other causes, too, only the inspection shows which of them is present in the particular unit. Voltage spikes, for example from a weak battery or a jump start, put additional strain on the electronics.

How can you tell that the 89170-42B80 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, an error message appears there, the diagnostic tool does not find the control unit, or the fault memory cannot be cleared. In these cases, the airbags and seatbelt pretensioners may not be able to deploy in an emergency.

The airbag warning light is the most important warning sign. If it stays on, have the system checked promptly.

Even a diagnostic tool without a connection to the control unit points to a fault. The control unit, the cables and the plugs must then all be checked.

Which vehicles is the 89170-42B80 fitted in?

The airbag control unit 89170-42B80 is fitted in these vehicles: Toyota bZ4X XC10 (2022-2025) and XC10 Facelift (from 2025).

The following vehicles belong to this part number:

• Toyota bZ4X XC10 (2022-2025)
• Toyota bZ4X XC10 Facelift (from 2025)

Before you remove the unit, compare the part number on the label with this page. The comparison only confirms that you have the correct unit. Regardless of this, have the fault memory read out, because only the log 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 89170-42B60, 89170-42E70.

How does the repair of the 89170-42B80 work?

First have the fault memory read out and set the log aside. Then disconnect the battery and only afterwards remove the control unit. For testing, repairing and checking at Airbag24, the time frame is usually 3–4 working days.

Then create a repair order online and send the unit in well packed. At Airbag24 it is tested on the test bench, defective components are repaired, the crash data is erased and a functional test is carried out. After that, 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 89170-42B80 get to Airbag24?

Shipping takes place as a parcel that you send yourself, or as a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

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