Airbag control unit with part number 89170-BZ730

What does the airbag control unit 89170-BZ730 do?

The airbag control unit 89170-BZ730 is the central control unit of the restraint system (SRS) in Toyota. It processes the measured values of the crash sensors and decides in an accident within milliseconds which airbags and seatbelt pretensioners are triggered.

It also monitors the entire system during operation and shows faults via the airbag warning light.

If the unit has registered an accident, it stores crash data and locks itself. Only the repair lifts this lock.

Why does the control unit 89170-BZ730 fail?

The most common cause at the 89170-BZ730 is crash data stored after an accident, even when no airbag has been triggered. A standard diagnostic tool cannot delete it. Other general causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The fact that crash data stays in the memory has one simple consequence: the control unit keeps reporting the fault, even though the electronics otherwise work.

The other causes mostly concern the components and connections inside the unit. Dirty or damp plug connections belong to this, as do voltage spikes that occur, for example, with a weak battery or a jump-start.

How can you tell that the 89170-BZ730 is defective?

A defect in the 89170-BZ730 shows up through the airbag warning light in the instrument cluster, which lights up permanently or intermittently, and through an error message in the instrument cluster. The diagnostic tool also finds no connection to the control unit, and the fault memory cannot be cleared.

With such a finding, airbags and seatbelt pretensioners may not be able to trigger in an emergency. The warning light is therefore not a trivial matter.

Have the finding checked promptly, rather than hoping the display will go out.

Which vehicles is the 89170-BZ730 fitted in?

These details apply to Toyota. The airbag control unit 89170-BZ730 is fitted in these vehicles: Toyota Avanza F650 Facelift (2015-2023).

You will find the models at a glance here:

• Toyota Avanza F650 Facelift (2015-2023)

First compare the part number on the label of the removed unit with this page. This only establishes that you have the right unit in hand. Also have the fault memory read out beforehand, because only the log shows whether the control unit is defective or whether 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-BZ730 work?

First have the fault memory read out and attach the log, then disconnect the battery and remove the control unit 89170-BZ730. Then create the repair order online and send the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

Make sure the battery is disconnected before removal. Only then take out the unit, because the restraint system must not be worked on while energised.

At Airbag24, the unit submitted is examined on the test bench. Defective components are replaced, stored crash data is deleted and a function test is carried out. Afterwards, 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-BZ730 get to Airbag24?

You send the control unit 89170-BZ730 as a parcel, or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

The printed repair order belongs in the parcel, and the unit should be packed to resist impact.