Airbag control unit with part number 89170-76590

What does the airbag control unit 89170-76590 do?

The 89170-76590 is the central control unit of the restraint system (SRS) for Lexus. It reads the signals from the crash sensors, determines in an accident within a fraction of a second which airbags and seatbelt pretensioners are to be triggered, and monitors the system continuously. After an accident it locks itself.

The unit shows faults via the airbag warning light in the instrument cluster. The evaluation is based on the acceleration and course of the impact.

In addition, the unit stores crash data after an accident.

Why does the control unit 89170-76590 fail?

Most often the cause lies in crash data stored after an accident, even if no airbag was triggered. A normal diagnostic tool cannot erase this data.

Further causes usually lie in the electronics or at the connections:

• aged electronic components
• cold solder joints
• moisture and corrosion on plug connections
• voltage spikes, for example from a weak battery or jump-starting

Which cause is present only becomes apparent when the removed unit is examined.

How can you tell that the 89170-76590 is defective?

A defect in the 89170-76590 shows up as the airbag warning light, which stays on permanently or comes on intermittently, as a fault message, or because the diagnostic tool cannot establish a connection. In an emergency, the airbags and seatbelt pretensioners may not deploy.

Typical signs are:

• airbag warning light that stays on or comes on intermittently
• fault message in the instrument cluster
• diagnostic tool finds no connection to the control unit
• fault memory cannot be cleared

The signs alone do not prove that the control unit itself is the cause.

Which vehicles is the 89170-76590 fitted in?

The 89170-76590 is fitted in these vehicles: Lexus UX MZAA10 (from 2018).

The following vehicles currently belong to this part number:

• Lexus UX MZAA10 (from 2018)

Compare the part number on the label of the removed unit with this information. Have the fault memory read out beforehand, so that it is clear whether the control unit is affected and not a plug or a cable.

How does the repair of the 89170-76590 work?

First read out the fault memory and have the log ready, then disconnect the battery and remove the 89170-76590. Next, create a repair order online and pack the unit well. Airbag24 then repairs it, and your own unit goes back.

Take care not to damage the unit during removal. Enclose the log of the fault memory with the parcel, as it helps with the check.

At Airbag24, the unit is examined on the test bench, defective components are replaced, stored crash data is erased and a function test is carried out. Processing usually takes 3–4 working days and covers only this checking, repair 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 89170-76590 get to Airbag24?

You send the control unit 89170-76590 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

Put the printed repair order in the parcel and pack the control unit shock-proof.