Airbag control unit with part number 89170-52N40

What does the airbag control unit 89170-52N40 do?

The airbag control unit 89170-52N40 forms the switching centre of the restraint system (SRS) in Toyota. It evaluates the crash sensors, decides in an emergency whether airbags and seatbelt pretensioners are triggered, and checks the system continuously. After an accident, it stores crash data and locks itself.

It receives the signals from the crash sensors and passes on the triggering commands as soon as the evaluation requires a decision. This decision must be made in an instant, so the electronics work without detours. The unit reports a fault via the airbag warning light.

Why does the control unit 89170-52N40 fail?

The most common cause is crash data stored after an accident, even if no airbag has triggered, because a normal diagnostic tool does not remove it. Further triggers are aging electronic components, cold solder joints, corrosion and moisture on plug connectors, and voltage spikes.

Crash data remains in the memory even if the vehicle appears externally unremarkable again.

Aging electronic components, cold solder joints and corrosion on plug connectors are typical weak points of such units. Moisture and voltage spikes, for example from a weak battery or a jump start, can also cause faults.

How can you tell that the 89170-52N40 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, a fault message appears in the instrument cluster, and the diagnostic tool finds no connection to the control unit. If the fault memory also cannot be erased, this indicates a defect. Airbags and seatbelt pretensioners may then not trigger in an emergency.

If the light only comes on now and then, the check is just as important as with permanent lighting. The light reports a detected fault, so it is worth having it checked even if the vehicle seems unremarkable in daily use.

Which vehicles is the 89170-52N40 fitted in?

The airbag control unit 89170-52N40 of Toyota is fitted in these vehicles: Toyota Yaris XP130 2nd Facelift (2017-2020), XP130 (2010-2014) and XP130 1st Facelift (2014-2017). You check the match with your vehicle using the papers.

We have listed the matching vehicles for this part number here:

• Toyota Yaris XP130 2nd Facelift (2017-2020)
• Toyota Yaris XP130 (2010-2014)
• Toyota Yaris XP130 1st Facelift (2014-2017)

If the part number on the label of the removed unit matches this page, you have the correct unit; the comparison tells you nothing more. Before removal, you have the fault memory read out, because only this shows whether the control unit itself is defective or a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 2310009950, 89170-0D300, 89170-0D320, 89170-0D590, 89170-0D600, 89170-0D620.

How does the repair of the 89170-52N40 work?

You first have the fault memory read out and attach the log to the unit. Then you disconnect the battery, only then remove the control unit, and create a repair order online before you send it in well packed.

Airbag24 checks the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. Processing usually takes 3–4 working days; this period covers only checking, repairing and testing at Airbag24. Afterwards, the 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 89170-52N40 get to Airbag24?

You either send the control unit 89170-52N40 as a parcel, or you book a UPS collection for an extra charge. Airbag24 sends the unit back to you via UPS after the repair.

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