Airbag control unit with part number 89170-76520

What does the airbag control unit 89170-76520 do?

The airbag control unit 89170-76520 coordinates the restraint system (SRS) of Lexus. It reads the crash sensors, determines within milliseconds in an accident which airbags and seatbelt pretensioners to trigger, and checks the entire system continuously. Detected faults appear via the airbag warning light.

After an accident, the unit writes crash data to its memory and then locks itself.

For the rest of the time, it works unobtrusively. Any faults it finds are stored in the fault memory, which a workshop can read out with a diagnostic tool.

Why does the control unit 89170-76520 fail?

The 89170-76520 most often fails because of stored crash data from an accident, even if no airbag has deployed. A standard diagnostic tool cannot erase it. Other causes include aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes.

The stored crash data remains until Airbag24 removes it during the repair. It has an effect even when the airbags were left undamaged.

The other causes lie in the electronics and the connections. Components age there, solder joints can go cold, moisture and corrosion attack plug connectors, and voltage spikes, for example with a weak battery or jump-starting, strain the unit.

Which of these applies is shown by the inspection of the unit.

How can you tell that the 89170-76520 is defective?

The airbag warning light in the instrument cluster shows the fault in the 89170-76520 when it lights up permanently or intermittently. Added to this are an error message in the instrument cluster, a diagnostic tool with no connection to the control unit, and a fault memory that cannot be cleared. In that case, airbags and seatbelt pretensioners may not deploy in an emergency.

The warning light is therefore the most important signal the vehicle gives you. If it stays on or keeps recurring, have the system checked promptly.

The other signs should also be taken seriously.

Which vehicles is the 89170-76520 fitted in?

The control unit 89170-76520 is fitted in these vehicles: Lexus UX MZAA10 (from 2018).

The following list shows the models to which this part number is assigned.

• Lexus UX MZAA10 (from 2018)

Compare the part number on the label of the removed unit with this page. This only confirms that it is the right unit. Also have the fault memory read out before removal, because only this result shows whether the control unit is defective or whether a plug or cable is the cause.

How does the repair of the 89170-76520 work?

You start by having the fault memory read out and enclosing the log. Then disconnect the battery and only afterwards remove the control unit 89170-76520. Next, create a repair order online and send in the well-packed unit.

Airbag24 checks the unit on the test bench, replaces defective components, erases the stored crash data and performs a function test. Afterwards, the unit goes back to you.

Processing at Airbag24 usually takes 3–4 working days. This period covers only the checking, repairing and testing. 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 89170-76520 get to Airbag24?

Either you send the control unit 89170-76520 as a parcel, or you book a UPS collection for an extra charge. The return after the repair is also handled by UPS.

You place the printed repair order in the parcel and pack the unit shock-proof.