Airbag control unit with part number 89170-42A40

What does the airbag control unit 89170-42A40 do?

The control unit 89170-42A40 is the airbag control unit for Toyota and controls the triggering of the airbags and seatbelt pretensioners. In an impact, it evaluates the crash sensors, and the decision is made within milliseconds.

During operation, the unit monitors the components of the system continuously and indicates faults via the airbag warning light.

After an accident, it stores crash data. It then remains locked.

Why does the control unit 89170-42A40 fail?

The most common cause on the 89170-42A40 is crash data stored after an accident, even if no airbag has deployed. Other causes include aged components, moisture at plug connections and voltage spikes.

An ordinary diagnostic tool cannot erase the crash data. Airbag24 removes it as part of the repair.

The other causes include the ageing of the electronics, cold solder joints, and moisture and corrosion on plugs. Voltage spikes from a weak battery or from jump-starting place additional strain on the components.

How can you tell that the 89170-42A40 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently if the 89170-42A40 has a fault. In addition, there are error messages and a diagnostic tool without a connection.

Airbags and seatbelt pretensioners may possibly fail to trigger in an emergency if the control unit is defective. Signs also include:

• Error message in the instrument cluster
• Diagnostic tool receives no contact with the control unit
• Fault memory cannot be erased
• Warning light stays on intermittently and then goes out again

Which vehicles is the 89170-42A40 fitted in?

The 89170-42A40 is fitted in these vehicles: Toyota RAV4 XA50 (from 2018). This list shows you whether your vehicle is included.

The vehicles are listed here:

• Toyota RAV4 XA50 (from 2018)

Comparing the part number on the label with this page only confirms that you have removed the correct unit. Whether the control unit is defective or a plug or cable is the cause is shown only by the fault memory once it has been read out.

For the same vehicles, we also repair control units with the part numbers 150800-4431, 152100-0262, 152100-4560, 89170-42400, 89170-42870, 89170-42A60.

How does the repair of the 89170-42A40 work?

First have the fault memory read out and attach the log. Then disconnect the battery and remove the control unit 89170-42A40. Airbag24 generally needs 3–4 working days for inspection, repair and testing.

Afterwards, create the repair order online and send the unit in well packed. Airbag24 tests it on the test bench, replaces defective components, erases the crash data and carries out a function test.

Your own unit is then 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 89170-42A40 get to Airbag24?

For sending the control unit 89170-42A40, you can use a parcel to Airbag24 or a UPS collection, which is booked for an extra charge. The return after the repair is made by UPS.

The printed repair order goes into the parcel. Pack the unit so that it is shock-resistant.