Airbag control unit with part number 89170-04291

What does the airbag control unit 89170-04291 do?

The airbag control unit 89170-04291 controls the restraint system (SRS) of Toyota. It continuously evaluates the signals from the crash sensors, decides in a fraction of a second during an accident which airbags and seatbelt pretensioners to trigger, and reports faults via the airbag warning light in the instrument cluster.

After an accident, the unit stores crash data and is locked afterwards. In the vehicle it works in the background and continuously checks the connections to the sensors, seatbelt pretensioners and airbags.

The system also includes the wiring harnesses, the sensors themselves and the airbags. The control unit is the central point where all signals converge.

Why does the control unit 89170-04291 fail?

The most common cause is stored crash data after an accident, even if no airbag was deployed; a normal diagnostic tool cannot erase it. Other causes include aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

Crash data is created when the control unit registers and stores an accident. It then remains in the unit's memory.

Electronics age over time, solder joints can become cold, and moisture attacks plug connections. Voltage spikes when starting or during a jump start put additional strain on the unit.

How can you tell that the 89170-04291 is defective?

The airbag warning light in the instrument cluster stays on permanently or lights up from time to time. Further signs are a fault message on the display, no connection between the diagnostic tool and the control unit, and a fault memory that cannot be cleared.

In the event of a defect, airbags and seatbelt pretensioners may fail to deploy in an emergency. A lit warning light is therefore a reason to have the system checked promptly.

The control unit reports such faults itself. The warning is therefore a direct signal from the system, not a chance finding.

Which vehicles is the 89170-04291 fitted in?

The 89170-04291 is fitted in these vehicles: Toyota Tacoma N200 (2004-2015).

The vehicles stored for this part number are listed below.

• Toyota Tacoma N200 (2004-2015)

Compare the part number on the label of the removed unit with this page. This only confirms that it is the correct unit. Have the fault memory read out beforehand, because only that 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 89170-04420, 89170-04570, 89170-04600, 89170-04650.

How does the repair of the 89170-04291 work?

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

This order is for safety: the control unit is only removed after the readout and after the battery has been disconnected.

At Airbag24 the unit is examined on the test bench, defective components are replaced, stored crash data is erased, and a function test follows. Afterwards your own unit is returned to you. Processing usually takes 3–4 working days, and this time covers only the testing, repair and checking at Airbag24.

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 89170-04291 get to Airbag24?

Either you send the unit off as a parcel, or you book a UPS collection for an extra charge. Airbag24 then returns the repaired unit to you by UPS.

Put the printed repair order into the parcel and pack the unit shock-resistant.