Airbag control unit with part number 89170-BZA50

What does the airbag control unit 89170-BZA50 do?

The airbag control unit 89170-BZA50 handles the restraint system (SRS) of Toyota. It evaluates the signals from the crash sensors and, in a crash, decides within milliseconds which airbags and seatbelt pretensioners are triggered, while monitoring the entire system. After an accident it records crash data and locks itself.

The sensors report accelerations to the unit, which compares these values with stored criteria. This check only works if the control unit itself operates reliably.

Self-diagnosis runs continuously in the background. The unit stores any faults it finds and displays them.

Why does the control unit 89170-BZA50 fail?

Stored crash data is the most common cause, even if no airbag was triggered in the accident. A standard diagnostic tool cannot erase it. Other possible causes include aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data is stored inside the unit and is not visible from outside. It is only removed during the repair.

The other causes concern the hardware. Solder joints, plug contacts and components react to age, moisture and voltage spikes, for example from a weak battery or jump-starting.

How can you tell that the 89170-BZA50 is defective?

The airbag warning light in the instrument cluster indicates a fault in the 89170-BZA50 when it stays on permanently or intermittently. Other signs include an error message in the instrument cluster, no connection to the diagnostic tool, and a fault memory that cannot be cleared.

The airbag warning light is the clearest sign the vehicle gives. It is accompanied by an error message in the instrument cluster.

If there is no connection to the diagnostic tool because the control unit does not respond, the situation is serious. In that case the airbags and seatbelt pretensioners may not trigger in an emergency.

Which vehicles is the 89170-BZA50 fitted in?

The airbag control unit 89170-BZA50 is fitted in these vehicles: Toyota Avanza F650 Facelift (2015-2023).

The assignment covers these models:

• Toyota Avanza F650 Facelift (2015-2023)

Comparing the part number on the removed unit with this page only confirms that it is the correct unit. Have the fault memory read out beforehand, so it becomes clear whether the control unit is defective or a connector 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-BZA50 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit 89170-BZA50. Then create a repair order online and send the unit in, well packed.

Airbag24 examines the unit on the test bench. Defective components are specifically replaced, the crash data is erased and a function test follows. The unit then goes back to you.

Work at Airbag24 usually takes 3–4 working days.

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-BZA50 get to Airbag24?

You send the control unit 89170-BZA50 as a parcel, or you book a UPS collection for an extra charge. After the repair, UPS returns the unit.

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