Airbag control unit with part number 89170-04721

What does the airbag control unit 89170-04721 do?

The airbag control unit 89170-04721 is the central control unit of the restraint system (SRS) of Toyota. It evaluates the crash sensors and in a crash decides within milliseconds which airbags and seatbelt pretensioners are triggered.

At the same time it monitors the entire system. It reports faults via the airbag warning light.

After a crash the unit stores crash data and locks itself. Only the repair releases the lock.

Why does the control unit 89170-04721 fail?

The most common cause with the 89170-04721 is crash data stored after an accident, even if no airbag was triggered. Other factors include aged electronics, solder joints, moisture and corrosion, and voltage spikes.

Crash data cannot be erased with a standard diagnostic tool. Airbag24 erases it as part of the repair.

The other causes range from aged components to cold solder joints and moisture on plugs. Voltage spikes, for example from a weak battery or a jump start, can also play a role.

How can you tell that the 89170-04721 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently on the 89170-04721, together with a fault message in the instrument cluster. In addition, the diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared.

Such signs indicate that the system has detected a fault. In the event of a defect, airbags and seatbelt pretensioners may not trigger in a crash. Take the warning light seriously for that reason.

Which vehicles is the 89170-04721 fitted in?

The airbag control unit 89170-04721 is fitted in these vehicles: Toyota Tacoma N300 (2015-2019) and N300 Facelift (2019-2023).

The vehicles for this part number are listed below.

• Toyota Tacoma N300 (2015-2019)
• Toyota Tacoma N300 Facelift (2019-2023)

Matching the part number on the label of the removed unit with this page only ensures that it is the right unit. Having the fault memory read out before the control unit is removed shows whether the control unit itself or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 89170-04080, 89170-04120, 89170-04150, 89170-04570.

How does the repair of the 89170-04721 work?

First have the fault memory of the 89170-04721 read out, and the log goes with the unit. Then disconnect the battery and remove the control unit. Afterwards create a repair order online and send the unit in well packed.

At Airbag24 the unit is checked on the test bench, defective components are replaced, and the crash data is erased. A function test follows.

Processing at Airbag24 usually takes 3–4 working days. This period covers only checking, repairing and testing on our premises.

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 89170-04721 get to Airbag24?

You send the 89170-04721 as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back by UPS.

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