Airbag control unit with part number 89170-BZ720

What does the airbag control unit 89170-BZ720 do?

The airbag control unit 89170-BZ720 coordinates the restraint system (SRS) of Toyota. It evaluates the crash sensors, decides within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously.

The unit detects faults itself and reports them via the airbag warning light in the instrument cluster.

After an accident it creates crash data and then locks itself.

Why does the control unit 89170-BZ720 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered; a normal diagnostic tool cannot erase it. Aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes are also possible causes.

The crash data remains stored in the control unit and prevents normal diagnosis. Airbag24 removes it in a targeted way during the repair so that the unit can then be checked properly.

Aged components, cold solder joints and moisture at plug connections are typical weak points of electronic assemblies. Voltage spikes, for example from a weak battery or when connecting jump leads, can also cause damage.

How can you tell that the 89170-BZ720 is defective?

A defect shows up as an airbag warning light that stays on permanently or intermittently, as a fault message in the instrument cluster, as a lack of contact with the diagnostic tool, and as a fault memory that cannot be cleared.

In an emergency, airbags and seatbelt pretensioners may then not trigger. That is why the warning light should take priority over all other displays.

The warning is unambiguous: it shows the state of the system, and you should respond to it.

Which vehicles is the 89170-BZ720 fitted in?

The control unit 89170-BZ720 is fitted in these vehicles: Toyota Avanza F650 Facelift (2015-2023). You can check whether it matches your vehicle using the label.

Here is the list of vehicles:

• Toyota Avanza F650 Facelift (2015-2023)

Comparing the part number on the label with this page ensures that it is the right control unit. Additionally have the fault memory read out. Only this result 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-BZ720 work?

First have the fault memory read out and enclose the log with the parcel. Then disconnect the battery and remove the control unit. Next create a repair order online and send in the unit. Checking, repairing and testing at Airbag24 usually takes 3–4 working days.

The removal comes after disconnecting the battery, not before. Pack the unit carefully before you send it.

Airbag24 checks the control unit on the test bench, repairs the defective components, erases the stored crash data and carries out a function test. Afterwards 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-BZ720 get to Airbag24?

You send the control unit 89170-BZ720 as a parcel, or alternatively you book a UPS collection for an extra charge. After the repair Airbag24 brings the unit back to you by UPS.

Put the printed repair order in the parcel. The unit should be packed shock-proof.