Airbag control unit with part number 89170-76550

What does the airbag control unit 89170-76550 do?

The airbag control unit 89170-76550 is the central control unit of the restraint system (SRS) for Lexus. It evaluates the signals from the crash sensors, decides in a crash whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously. It reports faults via the airbag warning light.

The decision is made within milliseconds. Between events the unit carries out its monitoring without interruption.

After a crash the control unit stores crash data and locks itself.

Why does the control unit 89170-76550 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered. Further causes are aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes, for example from a jump start or a weak battery.

A standard diagnostic tool does not erase the crash data. It stays stored until Airbag24 removes it during the repair.

The other causes affect the electronics directly. Moisture and corrosion impair the plug connections, while voltage spikes stress components that were not designed for them.

How can you tell that the 89170-76550 is defective?

A defect shows up on the airbag warning light in the instrument cluster, which lights up permanently or intermittently, and on a fault message in the instrument cluster. In addition, the diagnostic tool cannot establish a connection to the control unit, and the fault memory cannot be cleared.

• Airbag warning light lights up permanently or intermittently
• Fault message in the instrument cluster
• No connection between diagnostic tool and control unit
• Fault memory cannot be cleared

With these signs, airbags and seatbelt pretensioners may possibly not trigger in a crash. Have the system checked promptly.

Which vehicles is the 89170-76550 fitted in?

For Lexus the following applies: the airbag control unit 89170-76550 is fitted in these vehicles: Lexus UX MZAA10 (from 2018).

Below is the list of vehicles recorded for this part number.

• Lexus UX MZAA10 (from 2018)

Matching the part number on the label of the removed unit with this page ensures that you have the right unit. The match does not show the cause. Read out the fault memory beforehand, because only that log shows whether the control unit is defective or a plug or cable is the cause.

How does the repair of the 89170-76550 work?

First read out the fault memory and attach the log. Then disconnect the battery and only then remove the control unit. Next create a repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, erases the crash data and carries out a function test. Afterwards your own unit is sent back to you. The 3–4 working days cover only this work at Airbag24.

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 89170-76550 get to Airbag24?

You send the 89170-76550 as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back to you by UPS.

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