Airbag control unit with part number 89170-BZA00

What does the airbag control unit 89170-BZA00 do?

The airbag control unit 89170-BZA00 is the central control unit of the restraint system (SRS) for Toyota. It evaluates the signals from the crash sensors and, in an accident, determines within milliseconds which airbags and seatbelt pretensioners are triggered.

At the same time it monitors the entire system continuously. If it detects a fault, it displays it via the airbag warning light in the instrument cluster.

After an accident the control unit stores crash data and then locks itself.

Why does the control unit 89170-BZA00 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered. A common diagnostic tool cannot delete this data. Other causes include aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes.

The crash data remains in memory after the event, even if no airbag has deployed. It cannot be removed with a normal diagnostic tool.

The remaining causes can be summarised in general terms. Electronics age over time, solder joints can go cold, and moisture or corrosion attack plug connectors. Voltage spikes, for example from a weak battery or a jump start, can also affect the control unit.

How can you tell that the 89170-BZA00 is defective?

A defect shows up through the airbag warning light in the instrument cluster, which lights up permanently or intermittently, through an error message in the instrument cluster, through a missing connection from the diagnostic tool to the control unit, or through a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then possibly not trigger.

• Airbag warning light lights up permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool cannot establish a connection to the control unit
• Fault memory cannot be cleared

If the warning light comes on, have the vehicle checked promptly, because it is the direct indication of a fault in the restraint system.

Which vehicles is the 89170-BZA00 fitted in?

The control unit 89170-BZA00 is fitted in these vehicles: Toyota Avanza F650 Facelift (2015-2023).

Use of this part number in the following vehicles is known:

• Toyota Avanza F650 Facelift (2015-2023)

Comparing the part number on the label of the removed unit with this page ensures that you have the correct unit. Have the fault memory read out beforehand as well, because only that result shows whether the control unit itself is affected or whether a plug or cable is.

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-BZA00 work?

First read out the fault memory and enclose the log. Then disconnect the battery and only then remove the control unit. Create the repair order online and send the unit in well packed. At Airbag24, inspection, repair and function test usually take 3–4 working days.

Airbag24 inspects the control unit on the test bench and replaces defective components. The stored crash data is deleted during this, followed by 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-BZA00 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back to you by UPS.

Put the printed repair order in the parcel and pack the control unit shock-proof before it leaves.