Airbag control unit with part number 89170-12E20

What does the airbag control unit 89170-12E20 do?

The airbag control unit 89170-12E20 is the central control unit of the restraint system (SRS) for Toyota. It evaluates the crash sensors and, in an accident, determines within milliseconds which airbags and seatbelt pretensioners are triggered.

It monitors the system throughout the whole journey and keeps faults stored in memory. The airbag warning light in the instrument cluster shows you when something is wrong.

After an accident, the unit stores crash data and locks itself. Only the repair lifts the lock.

Why does the control unit 89170-12E20 fail?

Most often, crash data stored after an accident is the cause, even if no airbag has deployed. In addition there are ageing electronic components, cold solder joints, moisture and corrosion on plugs, and voltage spikes.

Crash data remains in the unit, and a normal diagnostic tool does not erase it. The control unit can therefore report faults even though the vehicle appears unremarkable from the outside.

The other triggers come on gradually. A component ages, a solder joint becomes cold over time, and moisture makes its way into a plug contact. Voltage spikes, for example from a weak battery or a jump start, can also affect the electronics.

Airbag24 erases the crash data during the repair. The other causes cannot be reliably identified without an inspection.

How can you tell that the 89170-12E20 is defective?

A defect shows up as the airbag warning light in the instrument cluster, which stays on permanently or intermittently. In addition, a fault message appears, the diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared.

The warning light is the clearest warning the system gives. It does not come on without reason, so have the display checked promptly.

In an emergency, airbags and seatbelt pretensioners may fail to deploy. This also applies when the vehicle otherwise runs normally, so the warning should be taken seriously.

Which vehicles is the 89170-12E20 fitted in?

The 89170-12E20 is fitted in these vehicles: Toyota Corolla E170 (2013-2018).

The list below shows the vehicles to which this part number is assigned:

• Toyota Corolla E170 (2013-2018)

Take a two-step approach. Compare the part number on the label of the removed unit with this page, and you will know that it is the correct unit. Also have the fault memory read out, because only the result shows whether the control unit or a plug or cable is causing the fault.

For the same vehicles, we also repair control units with the part numbers 89170-02C70, 89170-12180, 89170-12G10, 89170-12N50.

How does the repair of the 89170-12E20 work?

The fault memory is read out first and the log is enclosed. Then disconnect the battery, remove the control unit and create the repair order online. Testing, repair and the function test at Airbag24 usually take 3–4 working days.

Airbag24 checks the control unit on the test bench, replaces defective components and erases stored crash data. The function test follows, and your own unit is then sent back to you.

The sequence protects you: the battery is disconnected before removal, not afterwards.

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 89170-12E20 get to Airbag24?

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

Enclose the printed repair order and pad the control unit so that it is shock-resistant in transit.