Airbag control unit with part number 89170-48020

What does the airbag control unit 89170-48020 do?

The airbag control unit 89170-48020 controls the restraint system of Toyota. It evaluates the signals from the crash sensors, decides in the event of an accident within fractions of a second which airbags and seatbelt pretensioners are triggered, and monitors the entire system during operation. After an accident it stores crash data and locks itself.

In everyday use the unit works unobtrusively in the background and continuously checks the connected components. If it detects a fault, it stores it in the fault memory and indicates it via the airbag warning light.

The crash data describe how the event proceeded. They remain in the control unit, and while the unit reports this condition, the vehicle cannot be run as usual with them stored in memory.

Why does the control unit 89170-48020 fail?

The most common cause is crash data stored after an accident, which cannot be erased with a normal diagnostic tool. Further causes are aged electronic components, cold solder joints, moisture and corrosion on plug connections, as well as voltage spikes, for example from a weak battery or jump-starting.

After an accident the control unit stores crash data, even if no airbag has triggered in the end. A normal diagnostic tool cannot remove these entries, and the fault remains.

• Aged electronic components that lose performance over time
• Cold solder joints inside the unit
• Moisture and corrosion on plug connections
• Voltage spikes in the vehicle electrical system, for example from a weak battery or a jump-start

These causes often occur together with ageing of the connections.

How can you tell that the 89170-48020 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and a fault message appears in the instrument cluster. The diagnostic tool cannot find the control unit, and a fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The airbag warning light in the instrument cluster is the most visible sign. It lights up permanently or intermittently as soon as the control unit detects a fault, and it may be accompanied by a fault message on the display.

It becomes more serious when the diagnostic tool cannot connect to the control unit or the fault memory cannot be cleared. Both indicate that something is wrong in the system and should be clarified before removal.

Which vehicles is the 89170-48020 fitted in?

The airbag control unit 89170-48020 is fitted in these vehicles: Toyota Highlander XU20 Facelift (2004-2007) and XU20 (2001-2003). The part number only tells you which unit it is, not whether it is defective.

The list below shows the vehicles recorded for this part number. Check your vehicle against it.

• Toyota Highlander XU20 Facelift (2004-2007)
• Toyota Highlander XU20 (2001-2003)

Compare the part number on the label of the removed unit with this page, to make sure it is the correct unit. Have the fault memory read out beforehand. Only the 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 89170-48090, 89170-48150.

How does the repair of the 89170-48020 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Then create a repair order online and send the unit in. Airbag24 checks the unit, repairs defective components, erases stored crash data and carries out a function test.

You begin with the readout, after which the battery is disconnected and the control unit removed, in that order.

The repair order is created online, and the unit is packed well. The log is enclosed with the order so that the details of the fault are complete.

On the test bench, Airbag24 examines the unit and repairs defective components. Stored crash data is erased, followed by the function test. Processing at Airbag24 usually takes 3–4 working days.

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 89170-48020 get to Airbag24?

You send the control unit as a parcel to Airbag24 or book a UPS collection for an extra charge. After the repair, Airbag24 returns your own unit to you by UPS.

Place the printed repair order in the parcel and pack the control unit shockproof.