Airbag control unit with part number 89170-76320

What does the airbag control unit 89170-76320 do?

The airbag control unit 89170-76320 controls the restraint system (SRS) in Lexus. If the sensors detect an impact, it selects within milliseconds the airbags and seatbelt pretensioners that are to trigger. After an accident it stores crash data and locks itself.

In addition the unit monitors the lines and components of the system continuously. If it finds a deviation, it stores a fault entry and reports the fault via the warning light in the instrument cluster. This way the state of the system remains traceable at all times.

Why does the control unit 89170-76320 fail?

The most frequent cause is crash data that remains in the unit after an accident, even if no airbag has been triggered; a normal diagnostic tool cannot erase it. Other triggers are aged electronic components, cold solder joints, moisture or corrosion at plug connections and voltage spikes.

Further causes at a glance:

• aged electronic components
• cold solder joints on the circuit board
• moisture and corrosion at plug connections
• voltage spikes, for example from a weak battery or jump start

The crash data cannot be erased with a normal diagnostic tool, because the control unit manages it itself. During the repair by Airbag24 it is erased.

How can you tell that the 89170-76320 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and a fault message appears in the instrument cluster. The diagnostic tool cannot establish a connection to the control unit, and the fault memory cannot be cleared. Airbags and seatbelt pretensioners may then not trigger in an emergency.

The light is a clear warning sign and should not be ignored. It tells you that the system has stored a finding.

Which cause lies behind it is only clarified by reading the fault memory.

Which vehicles is the 89170-76320 fitted in?

The control unit 89170-76320 is fitted in these vehicles: Lexus UX MZAA10 (from 2018).

The vehicles recorded for this part number are shown below.

• Lexus UX MZAA10 (from 2018)

Comparing the part number on the label of your removed unit with this page confirms that it is the correct unit. The cause of the failure is not answered by this comparison.

Have the fault memory read before removal. This result shows whether the control unit is defective or whether a plug or cable is the cause.

How does the repair of the 89170-76320 work?

First have the fault memory read and attach the log to the unit. Then disconnect the battery, remove the control unit 89170-76320 and create the repair order online. Airbag24 checks the unit, repairs defective components, erases the crash data and runs a function test.

Processing at Airbag24 usually takes 3–4 working days. Afterwards your own unit comes back 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 89170-76320 get to Airbag24?

You send the control unit 89170-76320 as a parcel or book a UPS collection for an extra charge. Return shipment after the repair is by UPS.

Place the printed repair order in the parcel. A shock-proof carton protects the unit on its way.