Airbag control unit with part number 89170-47520

What does the airbag control unit 89170-47520 do?

The airbag control unit 89170-47520 controls the restraint system (SRS) of Toyota. It evaluates the signals from the crash sensors, decides within milliseconds in a crash whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After a crash it stores crash data and locks itself.

Monitoring runs throughout the entire journey. The unit checks sensors, ignition stages and the wiring to the triggers. If it finds an irregularity, it shows it via the airbag warning light in the instrument cluster.

The control unit works together with sensors, wiring harness and display. A fault in one of these parts can therefore appear as an error in the control unit, even if the unit itself is in order.

Why does the control unit 89170-47520 fail?

The most common cause for the control unit 89170-47520 is stored crash data after an accident, even if no airbag has deployed. A standard diagnostic tool cannot delete this data. Aged components, cold solder joints, moisture and voltage peaks are also possible causes.

The crash data is held in the memory of the control unit itself. As long as it is stored there, the fault display in the vehicle stays visible.

The following causes are possible:

• aged electronic components
• cold solder joints on the circuit board
• moisture and corrosion at plug connectors
• voltage peaks, for example from a weak battery or jump-starting

How can you tell that the 89170-47520 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently on the control unit 89170-47520, and a fault message appears in the instrument cluster. If the diagnostic tool gets no connection to the control unit and the fault memory cannot be cleared, a defect is likely. In a real crash, airbags and seatbelt pretensioners may then fail to deploy.

Signs at a glance:

• airbag warning light that stays on permanently or intermittently
• fault message in the instrument cluster
• no connection to the diagnostic tool
• fault memory that cannot be cleared

The light is a sign that the system has detected a fault. Only the evaluation of the fault memory shows which cause lies behind it.

Which vehicles is the 89170-47520 fitted in?

The control unit 89170-47520 is fitted in: Toyota Prius III XW30 (2009-2012) and III XW30 Facelift (2012-2016).

The following overview lists the vehicles to which this part number is assigned.

• Toyota Prius III XW30 (2009-2012)
• Toyota Prius III XW30 Facelift (2012-2016)

Compare the part number on the label of the removed unit with this page. This only ensures that it is the right unit. Before sending it in, also have the fault memory read out, because only this result 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 89170-47100, 89170-47101, 89170-47110, 89170-47111, 89170-47120, 89170-47140.

How does the repair of the 89170-47520 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only afterwards remove the control unit 89170-47520. Next, create a repair order online and send the well-packed unit in.

Airbag24 checks the unit on the test bench, replaces defective components, deletes stored crash data and carries out a function test. Your own unit is then sent back to you. Processing at Airbag24 usually takes 3–4 working days.

The order of these steps is for safety reasons and is therefore binding. 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 89170-47520 get to Airbag24?

You send the control unit 89170-47520 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Put the printed repair order into the parcel and pack the unit shockproof.