Airbag control unit with part number 89170-35420

What does the airbag control unit 89170-35420 do?

The 89170-35420 is the central control unit of the restraint system (SRS) of Toyota. It evaluates the crash sensors, decides in an accident within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After an accident it stores crash data and locks itself.

The unit reports faults in the system via the airbag warning light, so it becomes recognisable that the system has detected something.

The function depends on the unit acting without delay in an emergency.

Why does the control unit 89170-35420 fail?

The most common cause is stored crash data that remains in the unit after an accident, even if no airbag was triggered. A normal diagnostic tool does not make it disappear. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Aged electronic components lose some of their function over time. In addition, cold solder joints can cause contact problems.

Moisture and corrosion at plug connections lead to unclean signals. Voltage spikes arise, for example, from a weak battery or a jump start and can load the unit.

How can you tell that the 89170-35420 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, a fault message appears, the diagnostic tool gets no connection to the control unit, or the fault memory cannot be cleared. Airbags and seatbelt pretensioners may then fail to trigger in an emergency.

The warning light is the clearest sign. A fault message in the instrument cluster is also a hint, even if it is shown only briefly.

The fault memory records such events and shows what the system has registered.

Which vehicles is the 89170-35420 fitted in?

The 89170-35420 is fitted in these vehicles: Toyota FJ Cruiser GSJ15 (2006-2022).

Here follows the list of vehicles we have on record for this part number.

• Toyota FJ Cruiser GSJ15 (2006-2022)

A comparison of the part number on the label of the removed unit with this page confirms that it is the right unit. Whether the control unit itself is defective or a plug or cable forms the cause is shown only by reading out the fault memory. Therefore have it read out beforehand.

For the same vehicles, we also repair control units with the part numbers 89170-35230, 89170-35270, 89170-35280, 89170-35290, 89170-35300, 89170-35320.

How does the repair of the 89170-35420 work?

First have the fault memory read out and attach the log. Then disconnect the battery, remove the control unit and create an online repair order. At Airbag24 testing, repairing and function testing usually take 3–4 working days.

The sequence is mandatory for safety reasons. Only after the battery has been disconnected may the control unit leave the vehicle; afterwards it is sent in well packed.

At Airbag24 the unit is examined on the test bench. Defective components are repaired, stored crash data is deleted, and finally a function test is carried out. 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 89170-35420 get to Airbag24?

Shipping is by parcel; alternatively you book a UPS collection for an extra charge. Airbag24 also returns the repaired unit by UPS.

The printed repair order and shock-proof packaging of the unit belong in the parcel.