Airbag control unit with part number 89170-BZA40

What does the airbag control unit 89170-BZA40 do?

In the Toyota the airbag control unit 89170-BZA40 is the control unit of the restraint system (SRS). In a collision it evaluates the crash sensors and decides within milliseconds which airbags and seatbelt pretensioners are triggered.

Even outside an accident it monitors the system. If it detects a fault, it indicates this via the airbag warning light.

After an accident the unit stores crash data and is locked afterwards.

Why does the control unit 89170-BZA40 fail?

Stored crash data is the most common cause, even when no airbag has deployed. In addition, aged components, cold solder joints, moisture and corrosion, as well as voltage spikes, can cause the failure.

A normal diagnostic tool cannot erase the crash data. The data therefore remain in the memory even if the vehicle then drives normally.

The other causes are of a general nature. Electronics age, moisture creeps into plug connections, and voltage spikes occur when the battery is weak or a jump start is given.

How can you tell that the 89170-BZA40 is defective?

The airbag warning light signals the defect when it is lit permanently or intermittently. In addition, an error message in the instrument cluster, a missing contact with the diagnostic tool or a fault memory that cannot be cleared stand out.

The warning light is the most important sign that something is wrong in the restraint system. It indicates the defect and should therefore not be ignored.

While the fault persists, the airbags and seatbelt pretensioners may not trigger in an emergency.

Which vehicles is the 89170-BZA40 fitted in?

The 89170-BZA40 is fitted in these vehicles: Toyota Avanza F650 Facelift (2015-2023).

The list of matching vehicles follows here:

• Toyota Avanza F650 Facelift (2015-2023)

Compare the part number on the label of the removed unit with this page. This ensures that you have the correct unit. Have the fault memory read out beforehand as well, because only the log shows whether the control unit is the cause or whether a plug or cable is causing the fault.

For the same vehicles, we also repair control units with the part numbers 17952812-928112, 17952815-928143, 89170-BZ440.

How does the repair of the 89170-BZA40 work?

First have the fault memory read out and enclose the log, then disconnect the battery and only then remove the control unit. Online you create a repair order and send in the well-packed unit. Checking, repairing and testing at Airbag24 usually takes 3–4 working days.

Airbag24 tests the unit on the test bench, replaces defective components, erases the crash data and carries out a function test. Your own unit is then returned to you.

The order of the first steps is fixed for safety reasons. 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-BZA40 get to Airbag24?

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

The printed repair order belongs in the parcel, and the control unit must be packed shockproof.