Airbag control unit with part number 89170-52K50

What does the airbag control unit 89170-52K50 do?

In the restraint system (SRS) of the Toyota, the airbag control unit 89170-52K50 takes over the main control. Using the impact sensors, it determines which airbags and seatbelt pretensioners trigger in a crash. In addition, after an accident it stores crash data and locks itself.

As soon as the unit detects a fault in the system, it stores the entry in the fault memory. The driver is also informed via the airbag warning light.

Why does the control unit 89170-52K50 fail?

The most common cause is crash data that remain in the unit after an accident, even without a triggered airbag. They cannot be removed with a usual diagnostic tool. Aged electronics, cold solder joints, moisture and corrosion on plug connections, and voltage spikes are also possible causes.

The crash data belong to the memory of the control unit. Reading out with normal equipment does not make them disappear, and only the repair at Airbag24 erases them specifically.

Aged electronics gradually lose reliability. Cold solder joints can interrupt the contact, and moisture and corrosion on plug connections impair signal transmission.

Voltage spikes are a further load, for example with a weak battery or when a jump start is connected.

How can you tell that the 89170-52K50 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently. This is accompanied by an error message, a diagnostic tool without connection to the control unit, and a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may therefore possibly not trigger.

The light is the clearest hint the system gives, but it says nothing yet about the cause.

Only reading out the fault memory narrows down the finding.

Which vehicles is the 89170-52K50 fitted in?

The control unit 89170-52K50 is fitted in these vehicles: Toyota Aqua NHP10 (2011-2015), NHP10 1st Facelift (2015-2017) and NHP10 2nd Facelift (2017-2021).

These vehicles are recorded for the part number:

• 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. That way you know it is the right unit, but this alone does not clarify the cause.

Before you remove the unit, have the fault memory read out. The result shows whether the control unit is defective or whether a plug or cable is responsible for the failure.

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

How does the repair of the 89170-52K50 work?

You have the fault memory read out first, and the log goes with the unit. Then you disconnect the battery and only then remove the control unit 89170-52K50 from the vehicle. Finally, you create the repair order online.

Airbag24 checks the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. Your own unit then comes back to you.

For checking, repairing and testing at Airbag24, 3–4 working days are generally scheduled. 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 89170-52K50 get to Airbag24?

You can send the control unit 89170-52K50 as a parcel or have it collected by UPS for an extra charge. After the repair, the return follows by UPS.

Enclose the printed repair order and pack the unit so that it withstands knocks.