Airbag control unit with part number 89170-0R400

What does the airbag control unit 89170-0R400 do?

The airbag control unit 89170-0R400 is the central control unit of the restraint system (SRS) in Toyota vehicles. It evaluates the signals from the crash sensors, decides within milliseconds in a crash which airbags and seatbelt pretensioners are triggered, and monitors the system continuously.

The monitoring covers the sensors, the ignition circuits and the lines to the warning display. If the unit detects a fault, it reports it via the airbag warning light in the instrument cluster, so you can read the state of the system in everyday use.

After an accident, the control unit stores crash data and locks itself. This state is part of how the unit operates and a fixed component of the restraint system's electronics.

Why does the control unit 89170-0R400 fail?

Stored crash data is the most common cause on the 89170-0R400, even when no airbag has deployed. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data remains stored in the unit, and an ordinary diagnostic tool cannot erase it. That is why an accident in which no airbag has deployed can still cause a fault in the unit.

Electronic components age, and solder joints can go cold. Moisture and corrosion attack the plug connections. Voltage spikes arise, for example, from a weak battery or when connecting jump leads.

How can you tell that the 89170-0R400 is defective?

A defect on the 89170-0R400 shows up as the airbag warning light, which lights up permanently or intermittently, as a fault message in the instrument cluster, and as a diagnostic tool that cannot establish a connection to the control unit. A fault memory that cannot be erased is also a sign of this.

In an emergency, airbags and seatbelt pretensioners may possibly not trigger with such a unit. Take the warning seriously.

The warning light reports the fault itself, so you do not need to search for it first.

Which vehicles is the 89170-0R400 fitted in?

The airbag control unit 89170-0R400 is fitted in these vehicles: Toyota RAV4 XA50 (from 2018).

The following list shows the vehicles assigned to this part number.

• Toyota RAV4 XA50 (from 2018)

Compare the part number on the label of the removed unit with this page, so that you can be sure you have the right unit. Also have the fault memory read out beforehand, since the 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 150800-4431, 152100-0262, 152100-4560, 89170-42400, 89170-42870, 89170-42A60.

How does the repair of the 89170-0R400 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Next, create the repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and runs a functional test. Checking, repairing and testing usually take 3–4 working days at Airbag24. Your own unit then goes back to you.

The sequence serves safety and must be followed. 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 89170-0R400 get to Airbag24?

You send the 89170-0R400 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

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