Airbag control unit with part number 89170-42800

What does the airbag control unit 89170-42800 do?

At Toyota the airbag control unit 89170-42800 forms the central control unit for the restraint system (SRS). It evaluates the crash sensors, determines in an accident within milliseconds which airbags and seatbelt pretensioners fire, and monitors the system throughout. Faults appear via the airbag warning light.

While driving, the unit works in the background. It is connected to the sensors, the airbags and the seatbelt pretensioners and checks these connections.

After an accident the control unit records crash data and locks itself.

Why does the control unit 89170-42800 fail?

The most common cause in the 89170-42800 is crash data that remained in memory after an accident, even if no airbag fired. An ordinary diagnostic tool does not erase it. Other causes are aged components, moisture at plug connectors, cold solder joints and voltage spikes.

Even without fired airbags, entries can remain in the memory. Airbag24 removes the crash data as part of the repair.

The remaining causes relate to ageing, moisture and voltage. Electronics age, moisture attacks plug connectors, and voltage spikes, for example with a weak battery or after a jump start, stress the electronics.

How can you tell that the 89170-42800 is defective?

A defect shows as an airbag warning light in the instrument cluster that lights permanently or intermittently. A fault message in the instrument cluster, no contact with the diagnostic tool or a fault memory that cannot be erased also appear on the 89170-42800.

The light reports the fault as soon as the system detects it, which makes it a central warning signal.

In an emergency, airbags and seatbelt pretensioners may not be able to fire as long as the fault persists. A prompt check is therefore sensible.

Which vehicles is the 89170-42800 fitted in?

The airbag control unit 89170-42800 is fitted in these vehicles: Toyota RAV4 XA50 (from 2018).

The vehicles are shown here:

• Toyota RAV4 XA50 (from 2018)

Matching the part number on the label with this page only confirms that you have removed the right unit, nothing more. Have the fault memory read out beforehand. Only its findings show whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 150800-4431, 152100-0262, 152100-4560, 89170-0R070, 89170-0R090, 89170-0R091.

How does the repair of the 89170-42800 work?

At the 89170-42800 you start by reading out the fault memory and attach the log to the unit. Then disconnect the battery and only then remove the control unit. You create a repair order online and send the unit in well packed. At Airbag24, checking, repairing and testing usually take 3–4 working days.

There, Airbag24 replaces defective components, removes the stored crash data and carries out a function test.

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. Afterwards the unit comes back to you.

How does the control unit 89170-42800 get to Airbag24?

You send the control unit 89170-42800 as a parcel or book a UPS collection for an extra charge. After the repair the unit goes back to you by UPS. You put the printed repair order in the parcel.

Pack the unit shockproof and so that nothing slips about in the box.