Airbag control unit with part number 89170-48E40

What does the airbag control unit 89170-48E40 do?

The airbag control unit 89170-48E40 coordinates the restraint system (SRS) of Toyota. It processes the measured values of the crash sensors, decides in a crash within milliseconds on the triggering of airbags and seatbelt pretensioners, and monitors the system continuously. Reported faults appear via the airbag warning light. After a crash the unit stores crash data and locks itself.

This monitoring runs as long as there is a power supply. The unit checks ignition circuits, wiring and the sensor connection and records every deviation in the fault memory.

Because the triggering decision and the monitoring lie within the same unit, it is central to the safety of the system.

Why does the control unit 89170-48E40 fail?

The most common cause is crash data that remains in the memory after an accident, even if no airbag has deployed. An ordinary diagnostic tool cannot remove it. Further causes include aged electronics, cold solder joints, moisture and corrosion on connectors, and voltage spikes, for example from a weak battery or a jump start.

Crash data does not have to mean that the control unit itself is damaged. It only shows that data was stored after an event.

The other causes develop over a longer period: components age, solder joints can break, and moisture attacks contacts. A steady power supply reduces the risk of such spikes.

How can you tell that the 89170-48E40 is defective?

The airbag warning light in the instrument cluster indicates whether there is a defect: it lights up permanently or only intermittently. Accompanying this, a fault message appears in the instrument cluster, the diagnostic tool does not find the control unit, and the fault memory remains.

A defect cannot be recognised from the light itself, but from the faults that the control unit reports. That is why it is worth looking at the fault memory, even if the light only flickers briefly.

As long as the fault persists, airbags and seatbelt pretensioners may possibly fail to deploy in an emergency. A prompt check is therefore sensible.

Which vehicles is the 89170-48E40 fitted in?

The 89170-48E40 is fitted in these vehicles: Toyota Harrier XU80 (from 2020).

The matching models are compiled in the following list.

• Toyota Harrier XU80 (from 2020)

First compare the part number on the label of the removed unit with this page. That tells you only that it is the right unit, nothing more. Also have the fault memory read out beforehand. This log shows 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 89170-0E330.

How does the repair of the 89170-48E40 work?

The order is fixed for safety reasons: have the fault memory read out and enclose the log, disconnect the battery and only then remove the control unit. Then create the repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days.

At Airbag24 the unit is inspected on the test bench, defective components are repaired, and stored crash data is erased. A function test follows before your own unit goes back 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 89170-48E40 get to Airbag24?

Either you send the control unit as a parcel, or you arrange a UPS collection for an extra charge. Airbag24 sends it back by UPS after the repair.

Enclose the printed repair order with the parcel, and pack the control unit shock-resistant.