Airbag control unit with part number 89170-48E20

What does the airbag control unit 89170-48E20 do?

The airbag control unit 89170-48E20 is the control unit of the restraint system (SRS) in Toyota. It evaluates the crash sensors, determines in the event of a crash which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After an accident it stores crash data and locks itself.

The unit processes the sensor signals in the shortest possible time. Any faults it detects are reported via the airbag warning light in the instrument cluster.

Why does the control unit 89170-48E20 fail?

The most common cause of failure of the 89170-48E20 is crash data that remains in the unit after an accident, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Other causes are ageing electronics, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes, for example from a weak battery or a jump start.

The crash data remains in the memory because it belongs to the event and does not disappear on its own. That is why the cause only becomes apparent during diagnosis.

The other causes develop gradually. Electronic components lose quality over time, solder joints can give way, and moisture promotes corrosion. Voltage spikes, by contrast, act immediately, for example with a weak battery or a jump start.

How can you tell that the 89170-48E20 is defective?

You can recognise a defect in the 89170-48E20 by the airbag warning light in the instrument cluster lighting up permanently or intermittently. In addition there may be a fault message in the instrument cluster, a diagnostic tool without connection and a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

Watch for these signs:

• Airbag warning light lit permanently or intermittently
• Fault message in the instrument cluster
• Diagnostic tool cannot reach the control unit
• Fault memory remains despite an attempt to clear it

The warning light is a signal you should not ignore, because it indicates the fault.

Which vehicles is the 89170-48E20 fitted in?

The control unit 89170-48E20 is fitted in the following vehicles: Toyota Harrier XU80 (from 2020).

The vehicle list for this part number follows below:

• Toyota Harrier XU80 (from 2020)

Comparing the part number on the label of the removed unit with this page only shows whether it is the correct unit. Before you remove the unit, the fault memory should have been read out. Only this result shows whether the control unit is defective or whether a connector or a 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 89170-48E20 work?

On the 89170-48E20 you first read out the fault memory and enclose the log. Then you disconnect the battery, only then remove the control unit and create a repair order online. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 then checks the unit on the test bench, repairs the defective components, removes the stored crash data and tests the function. Afterwards your own unit is 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 89170-48E20 get to Airbag24?

You send the control unit 89170-48E20 yourself as a parcel, or you have it collected by UPS for an extra charge. Airbag24 also returns it to you by UPS after the repair.

The printed repair order is enclosed in the parcel, and the unit is packed shock-proof.