Airbag control unit with part number 89170-0C420

What does the airbag control unit 89170-0C420 do?

The 89170-0C420 is an airbag control unit that monitors the restraint system in Toyota vehicles. It evaluates the signals from the crash sensors, and in a crash it determines within milliseconds which airbags and seatbelt pretensioners fire.

The control unit checks the system continuously in the background. If it detects a fault, this appears via the airbag warning light in the instrument cluster.

If an accident has occurred, the unit stores crash data and then locks itself.

Why does the control unit 89170-0C420 fail?

Crash data from an accident in which no airbag deployed is the most common cause of failure. It remains in the unit, and a standard diagnostic tool cannot remove it.

Other causes are aged electronic components, cold solder joints, and moisture or corrosion on plug connections. Voltage spikes, for example from a weak battery or jump-starting, can also affect the unit.

Which cause applies only becomes clear through a precise test.

How can you tell that the 89170-0C420 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently if the 89170-0C420 is defective. Typical signs also include fault messages, a diagnostic tool without connection to the control unit, and a fault memory that cannot be cleared.

As long as the problem persists, airbags and seatbelt pretensioners may not deploy in an emergency. The light is therefore a clear reason to have the finding checked.

The control unit itself gives the warning; the test shows what lies behind it.

Which vehicles is the 89170-0C420 fitted in?

The 89170-0C420 is fitted in these vehicles: Toyota Tundra K30 (2007-2021).

You will find the vehicles in an overview below:

• Toyota Tundra K30 (2007-2021)

Comparing the part number on the unit with this page shows whether it is the matching unit, nothing more. Have the fault memory read out before you send the unit in, because only it 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 89170-0C440, 89170-0C450, 89170-0C451, 89170-0C452, 89170-0C490, 89170-0C581.

How does the repair of the 89170-0C420 work?

For the repair of the 89170-0C420, first have the fault memory read out and attach the log. Then disconnect the battery; only then remove the control unit. For testing, repairing and function testing at Airbag24, allow 3–4 working days as a rule.

For safety reasons this sequence is binding. Only after that do you create a repair order online and pack the unit well for dispatch.

At Airbag24 the unit is tested, defective components are repaired, stored crash data is erased and a function test is carried out. Your own unit is returned to you 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 89170-0C420 get to Airbag24?

Shipping is available as a parcel that you send yourself, or as a UPS collection for an extra charge for the control unit 89170-0C420. After the repair Airbag24 sends it back to you by UPS.

Place the printed repair order in the parcel, and pack the unit shock-resistant.