Airbag control unit with part number 89170-78151

What does the airbag control unit 89170-78151 do?

In an emergency, the airbag control unit 89170-78151 decides within milliseconds which airbags and seatbelt pretensioners are triggered. To do so, it evaluates the crash sensors; otherwise it monitors the restraint system for Lexus and shows faults via the airbag warning light.

After an accident, the control unit stores crash data and locks itself.

To keep this evaluation reliable, the electronics inside the unit are the core of every repair.

Why does the control unit 89170-78151 fail?

Stored crash data after an accident is considered the most common cause with the 89170-78151, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Other causes include ageing of components, cold solder joints, moisture and corrosion at the plug connections, and voltage spikes.

Crash data is created as soon as the unit registers an accident, regardless of whether any airbags deploy.

The remaining causes affect connections, components and the power supply; a weak battery or jump-starting can cause voltage spikes.

How can you tell that the 89170-78151 is defective?

The airbag warning light on the 89170-78151 lighting up permanently or intermittently is the clearest sign. Further signs are a fault message in the instrument cluster, a diagnostic tool without a connection and a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The light indicates the defect even if you notice nothing unusual in everyday driving.

Note down when the messages first appeared, as this information helps with the readout.

Which vehicles is the 89170-78151 fitted in?

The control unit 89170-78151 is fitted in these vehicles: Lexus NX AZ20 (from 2021).

You can see the assignment here:

• Lexus NX AZ20 (from 2021)

Comparing the part number on the label of the removed unit with this page only confirms the identity of the unit. Whether the control unit is defective or a plug or cable is the cause is shown only by the fault memory read out in advance.

For the same vehicles, we also repair control units with the part numbers 89170-F6010.

How does the repair of the 89170-78151 work?

First have the fault memory read out and enclose the log, then disconnect the battery and only then remove the control unit 89170-78151. Online you create a repair order, and the well-packed unit goes to Airbag24. For testing, repair and function check, Airbag24 usually allows 3–4 working days.

The bench test uncovers defective components, which are then replaced. Airbag24 deletes stored crash data before a function test concludes the work. Your own unit is then returned to you.

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 89170-78151 get to Airbag24?

You arrange the shipping of the 89170-78151 yourself, either as a parcel or via a UPS collection, which can be booked for an extra charge.

Enclose the printed repair order with the parcel and pad the unit so it is shock-proof.