Airbag control unit with part number 89170-52L90

What does the airbag control unit 89170-52L90 do?

The airbag control unit 89170-52L90 forms the central control unit of the restraint system (SRS) of Toyota. It evaluates signals from the crash sensors and decides within milliseconds, in the event of an accident, which airbags and seatbelt pretensioners are triggered.

At the same time it checks the connected components continuously, and faults appear on the airbag warning light. This keeps the system monitored during operation.

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

Why does the control unit 89170-52L90 fail?

The most common cause for the control unit 89170-52L90 is that crash data has been stored after an accident, even without an airbag having deployed. Other causes are aged components, cold solder joints, moisture and corrosion, and voltage spikes.

The other causes can be summarised briefly as follows:

• aged electronic components
• cold solder joints
• moisture and corrosion at plug connections
• voltage spikes, for example from a weak battery or a jump start

Crash data is one of the causes that reading out alone does not remove, because a standard diagnostic tool does not delete it.

How can you tell that the 89170-52L90 is defective?

A defect on the control unit 89170-52L90 shows itself through the airbag warning light in the instrument cluster, which stays on permanently or intermittently, and through an error message in the instrument cluster. In addition, the diagnostic tool gets no connection to the control unit, and the fault memory cannot be cleared.

These signs are easy to observe in everyday use. In an emergency, airbags and seatbelt pretensioners may not trigger. Have the system checked when these signs appear.

Which vehicles is the 89170-52L90 fitted in?

The control unit 89170-52L90 is fitted in these vehicles: Toyota Aqua NHP10 (2011-2015), NHP10 1st Facelift (2015-2017) and NHP10 2nd Facelift (2017-2021). Only the comparison of the part number shows which version is installed in your car.

The assignment at a glance:

• Toyota Aqua NHP10 (2011-2015)
• Toyota Aqua NHP10 1st Facelift (2015-2017)
• Toyota Aqua NHP10 2nd Facelift (2017-2021)

Compare the part number on the label of the removed unit with this page. This only ensures that you have the correct unit. Also have the fault memory read out beforehand, because it shows whether the control unit is defective or a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 152100-4560, 89170-42D50.

How does the repair of the 89170-52L90 work?

First read out the fault memory and enclose the log; then disconnect the battery and only after that remove the control unit 89170-52L90. Inspection, repair and function test at Airbag24 usually take 3–4 working days.

Next you create the repair order online and send in the well-packed unit. Airbag24 inspects it on the test bench, repairs defective components, deletes stored crash data and carries out a function test. Afterwards your own unit is sent back.

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 89170-52L90 get to Airbag24?

You send the control unit 89170-52L90 as a parcel, or book a UPS collection for an extra charge. Airbag24 sends it back to you by UPS after the repair.

Enclose the printed repair order and pack the unit shock-proof.