Airbag control unit with part number 89170-BZ550

What does the airbag control unit 89170-BZ550 do?

The airbag control unit 89170-BZ550 is the central unit of the restraint system for Toyota. It checks the crash sensors, selects the airbags and seatbelt pretensioners to trigger within a few milliseconds of an impact, and monitors the system permanently.

It shows faults via the airbag warning light in the instrument cluster.

After a crash, it creates crash data and remains locked afterwards. Only the repair lifts this lock.

Why does the control unit 89170-BZ550 fail?

The most common cause is crash data from an accident, even if no airbag has deployed. Standard diagnostic tools cannot erase it; Airbag24 removes it during the repair. Other causes are aged electronics, cold solder joints, moisture and corrosion on connectors, and voltage spikes, for example from jump-starting or a weak battery.

Which cause applies in an individual case only becomes clear during the test bench inspection.

Plug connections are prone to moisture and corrosion, which is why contacts and wiring are also part of the check.

How can you tell that the 89170-BZ550 is defective?

You can recognise a defect when the airbag warning light stays on permanently or intermittently. In addition, an error message appears in the instrument cluster, the diagnostic tool cannot find the control unit, and the fault memory cannot be cleared.

The indicator sits in the instrument cluster and clearly points to a fault in the restraint system. While the fault persists, the airbags and seatbelt pretensioners may not trigger in an emergency.

Which vehicles is the 89170-BZ550 fitted in?

The 89170-BZ550 is fitted in these vehicles: Toyota Avanza F650 Facelift (2015-2023). The information relates to the assignment of this part number, not to the individual car.

The individual vehicles are listed one below the other here:

• Toyota Avanza F650 Facelift (2015-2023)

Compare the part number on the label with this page. This only ensures that it is the right unit. Have the fault memory read out beforehand, because only the result 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 17952812-928112, 17952815-928143, 89170-BZ440.

How does the repair of the 89170-BZ550 work?

First have the fault memory read out and attach the log. Then disconnect the battery and only after that remove the control unit. Next, create a repair order online and pack the unit well for sending.

At Airbag24, the unit is tested, defective components are repaired, crash data is erased and a function test is carried out. Processing usually takes 3–4 working days. After that, your own unit is returned 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-BZ550 get to Airbag24?

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

Include the printed repair order and pack the unit shock-proof.