Airbag control unit with part number 89170-42E50

What does the airbag control unit 89170-42E50 do?

The airbag control unit 89170-42E50 controls the SRS for Toyota. It receives the signals from the crash sensors and decides within milliseconds which airbags and seatbelt pretensioners are triggered. It also monitors all components and reports faults via the airbag warning light.

Monitoring runs throughout every journey. If irregularities occur, the control unit creates an entry in the fault memory.

After an accident, it stores crash data and remains locked.

Why does the control unit 89170-42E50 fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Other causes include aged components, cold solder joints, moisture and corrosion at plugs, and voltage spikes from a weak battery or jump-starting.

Crash data remains stored after an impact, even if no airbag has deployed. A normal diagnostic tool cannot delete it. Airbag24 deletes it during the repair.

The other causes include components that age over the years, and solder joints that have gone cold. Moisture and corrosion at the plug connections disrupt the contact.

Voltage spikes in the vehicle electrical system put additional strain on the circuit.

How can you tell that the 89170-42E50 is defective?

A defect shows up as the airbag warning light in the instrument cluster staying on permanently or intermittently, and also as a fault message in the instrument cluster. The diagnostic tool may then find no connection to the control unit, and the fault memory cannot be erased. In an emergency, airbags and seatbelt pretensioners may fail to trigger.

The warning light in the instrument cluster is the most visible sign. It indicates a fault for as long as the cause remains.

A fault message in the instrument cluster, a diagnostic tool without a connection and a fault memory that cannot be erased also point to a problem. In this case, have the fault memory read out before you plan any further steps.

Which vehicles is the 89170-42E50 fitted in?

The control unit 89170-42E50 is fitted in these vehicles: Toyota bZ4X XC10 (2022-2025) and XC10 Facelift (from 2025).

The list below shows the vehicles to which this part number belongs:

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

A comparison of the part number on the label of the removed unit with this page confirms that it is the right unit. Nothing more. Therefore have the fault memory read out beforehand. Only this result shows whether the control unit is defective or whether a plug or a cable is causing the fault.

For the same vehicles, we also repair control units with the part numbers 89170-42B60, 89170-42E70.

How does the repair of the 89170-42E50 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Then create a repair order online and send the unit. At Airbag24, inspection, repair and testing usually take 3–4 working days.

The sequence is fixed for your safety: readout with log, then disconnect the battery, and only after that remove the unit. Pack the unit well before you send the repair order.

Airbag24 checks the unit on the test bench, repairs defective components and deletes stored crash data. A function test completes the work, and 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 89170-42E50 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns the unit to you by UPS.

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