Airbag control unit with part number 89170-BZ250

What does the airbag control unit 89170-BZ250 do?

Within the restraint system (SRS) of Toyota, the airbag control unit 89170-BZ250 is the central unit. It processes the readings from the crash sensors and, in an accident, determines within milliseconds which airbags and seatbelt pretensioners fire.

It also monitors the entire system continuously. If it detects a malfunction, it shows this via the airbag warning light in the instrument cluster.

After an accident the unit secures crash data, and then it remains locked.

Why does the control unit 89170-BZ250 fail?

The most common cause is stored crash data from an accident, even without a triggered airbag; an ordinary diagnostic tool cannot erase it. Ageing electronics, cold solder joints, moisture and corrosion on plugs, and voltage spikes from a weak battery or a jump start are also possible causes.

Crash data stays in the unit until it is specifically removed. The record is made on impact and then remains with the control unit unchanged.

Ageing electronics and cold solder joints go unnoticed in everyday use until a contact breaks or a circuit fluctuates.

Moisture and corrosion attack the plug connections, and voltage spikes stress the electronics, for example when the battery is weak or a jump start is given.

How can you tell that the 89170-BZ250 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and an error message appears in the instrument cluster as well. In addition, no connection to the diagnostic tool can be established, and the fault memory cannot be erased. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The light is a clear sign that the control unit has detected a fault, and it must not be ignored.

If one of these signs appears, a check follows.

Which vehicles is the 89170-BZ250 fitted in?

The 89170-BZ250 is fitted in these vehicles: Toyota Avanza F650 (2011-2015).

The listing names the assigned models and variants.

• Toyota Avanza F650 (2011-2015)

Comparing the part number on the label of the removed unit with this page shows that the unit matches this type. Only the fault memory, read out before removal, will show whether the control unit itself 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-BZ250 work?

First have the fault memory read out and the log enclosed, then disconnect the battery and only then remove the control unit. Online, you create a repair order and send the well-packed unit in. For testing, repair and checking at Airbag24, 3–4 working days are generally to be allowed.

Airbag24 examines the unit on the test bench, repairs defective components, erases crash data and carries out a function test; your own unit then 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-BZ250 get to Airbag24?

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

Enclose the printed repair order in the parcel; the packaging must be shock-resistant.