Airbag control unit with part number 89170-76410

What does the airbag control unit 89170-76410 do?

The airbag control unit 89170-76410 is the central control unit of the restraint system (SRS) at Lexus. It checks the signals from the crash sensors, decides in a collision whether airbags and seatbelt pretensioners are triggered, and monitors the system without interruption.

It records faults in the fault memory and reports them via the airbag warning light in the instrument cluster.

Crash data from a collision is stored, after which the unit locks itself.

Why does the control unit 89170-76410 fail?

Stored crash data from a collision is at the top of the causes on the 89170-76410, even if no airbag has deployed. Further triggers include aged components, moisture at connectors and voltage spikes.

Crash data cannot be removed with a standard diagnostic tool, so it remains available for evaluation.

The other triggers lie in the electronics itself, at the contacts or in the vehicle electrical system. These are older components, corrosion in plug connections and brief voltage spikes, for example from a weak battery.

How can you tell that the 89170-76410 is defective?

A defect shows on the 89170-76410 through the airbag warning light in the instrument cluster, which lights up permanently or intermittently. Typical accompanying signs are fault messages, a diagnostic tool without connection and a fault memory that cannot be cleared.

• Airbag warning light on intermittently or permanently
• Fault message in the instrument cluster
• Diagnostic tool receives no connection to the control unit
• Fault memory cannot be cleared

With such a finding, the airbags and seatbelt pretensioners may not be able to deploy in an emergency. The warning therefore calls for a prompt clarification.

Whether the control unit itself or the wiring causes the fault cannot be determined without reading it out.

Which vehicles is the 89170-76410 fitted in?

The 89170-76410 is fitted in these vehicles: Lexus UX MZAA10 (from 2018).

The list below sets out the vehicles in which this control unit is installed.

• Lexus UX MZAA10 (from 2018)

Check the part number on the label of the removed unit against this page, so that you are sure you have the correct unit. Also have the fault memory read out, because only that result shows whether the control unit or a cable is defective.

How does the repair of the 89170-76410 work?

First the fault memory is read out, and the log goes with the unit. Then you disconnect the battery and remove the control unit 89170-76410. Finally you create the repair order online and send the unit in well packed; at Airbag24 processing usually takes 3–4 working days.

At the Airbag24 premises the unit is checked on the test bench, defective components are repaired, the crash data is erased and a function test follows. After that the unit is 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 89170-76410 get to Airbag24?

Either you send the control unit 89170-76410 as a parcel, or you book a UPS collection for an extra charge. After the repair Airbag24 returns it to you by UPS.

Make sure the unit is packed shock-proof and enclose the printed repair order.