Airbag control unit with part number 89170-76641

What does the airbag control unit 89170-76641 do?

The 89170-76641 is the control unit of the restraint system (SRS) of Lexus. It processes the measurements from the crash sensors, decides in a crash within fractions of a second which airbags and seatbelt pretensioners are triggered, and checks the system continuously.

If the unit detects a fault, it shows it via the airbag warning light in the instrument cluster. This light is therefore the most important indication of the state of the system.

After an accident, the control unit creates crash data and remains locked afterwards. The lock ends only with a repair.

Why does the control unit 89170-76641 fail?

For the 89170-76641, the most common cause is stored crash data from an accident, even if no airbag has deployed. Further causes are aged components, cold solder joints, moisture on plugs and voltage spikes.

Besides the crash data, these points are mainly to be considered:

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

Crash data remains in memory, and a normal diagnostic tool cannot remove it. This explains why a simple fault search does not get anywhere at this point.

How can you tell that the 89170-76641 is defective?

On the 89170-76641, the airbag warning light in the instrument cluster indicates a fault when it lights up permanently or intermittently. Accompanying signs are a fault message, a failure of the diagnostic tool to connect, and a fault memory that cannot be cleared. Then the airbags and seatbelt pretensioners may not be able to deploy in an emergency.

Typical signs at a glance:

• airbag warning light on, permanently or intermittently
• fault message in the instrument cluster
• no connection between diagnostic tool and control unit
• fault memory cannot be cleared

The warning light is an unambiguous signal. Take it seriously and have the cause clarified.

Which vehicles is the 89170-76641 fitted in?

The 89170-76641 is fitted in these vehicles: Lexus UX MZAA10 (from 2018).

These models are known to us for this part number:

• Lexus UX MZAA10 (from 2018)

Comparing the part number on the label with this page ensures that the unit fits. Have the fault memory read out in addition, because only its content shows whether the control unit itself is defective or whether a connector or cable is causing the fault.

How does the repair of the 89170-76641 work?

For the repair of the 89170-76641, first read out the fault memory and enclose the log. Then disconnect the battery before removing the control unit. Then create a repair order online and pack the unit well for sending.

At Airbag24, the unit is examined on the test bench, defective components are repaired, the crash data is erased and a function test is carried out. Afterwards your own unit is returned to you.

Processing at Airbag24 usually takes 3–4 working days, counted only for inspection, 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 89170-76641 get to Airbag24?

You send the control unit 89170-76641 to us as a parcel, or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back by UPS.

The repair order is printed out and placed in the parcel. Pack the unit so that it arrives undamaged.