Airbag control unit with part number 89170-BZ400

What does the airbag control unit 89170-BZ400 do?

In the Toyota the airbag control unit 89170-BZ400 processes the signals from the crash sensors and, as the control unit of the SRS, decides which airbags and seatbelt pretensioners trigger in an accident. The decision is made within milliseconds.

It checks the system continuously and reports faults via the airbag warning light in the instrument cluster.

After an accident it stores crash data in memory and remains locked afterwards.

Why does the control unit 89170-BZ400 fail?

The most common cause is crash data from an accident that remains in the unit, even if no airbag has deployed. In addition there are aged components, cold solder joints, moisture and corrosion, as well as voltage spikes.

Crash data cannot be removed with a normal diagnostic tool. It therefore interferes with routine fault-finding.

The other causes are rather general in nature. Electronic components age, solder joints can become faulty, moisture attacks contacts, and voltage spikes occur when the battery is weak or a jump start is given.

How can you tell that the 89170-BZ400 is defective?

The airbag warning light indicates the fault, lighting up permanently or only intermittently. Error messages or communication problems at the diagnostic tool may also occur.

• airbag warning light in the instrument cluster, permanently or intermittently
• error message in the instrument cluster
• diagnostic tool cannot reach the control unit
• fault memory remains and cannot be cleared

While such a condition exists, airbags and seatbelt pretensioners may not trigger in an emergency. Treat the warning light as a warning signal.

Which vehicles is the 89170-BZ400 fitted in?

The 89170-BZ400 is fitted in these vehicles: Toyota Avanza F650 (2011-2015).

The list of vehicles follows in an overview:

• Toyota Avanza F650 (2011-2015)

Compare the part number on the label of the removed unit with this page, and then you know that it is the correct unit. Have the fault memory read out beforehand: only this log shows whether the control unit is defective or whether a plug or cable is responsible for the fault.

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-BZ400 work?

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

Airbag24 tests the unit on the test bench, replaces defective components, erases the crash data and runs a function test. The own unit then goes back to you.

This period of 3–4 working days relates solely to checking, repairing and testing at Airbag24. The order of the first steps is mandatory, because it secures safety during removal. 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-BZ400 get to Airbag24?

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

Put the printed repair order into the parcel and pack the control unit shockproof.