Airbag control unit with part number 89170-33T90

What does the airbag control unit 89170-33T90 do?

The airbag control unit 89170-33T90 is the central control unit of the restraint system (SRS) of Lexus. It assesses the signals of the crash sensors and decides within milliseconds in a crash which airbags and seatbelt pretensioners are triggered.

In addition it monitors the system continuously and shows faults via the airbag warning light in the instrument cluster. After an accident it stores crash data and locks itself; the lock is only lifted by the repair.

Why does the control unit 89170-33T90 fail?

The most common cause is crash data from an accident, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Aged components, cold solder joints, moisture and corrosion at plug connectors and voltage spikes are also possible causes.

Aged electronics are a cause in their own right: over time components in the control unit can weaken and cause malfunctions.

Cold solder joints as well as moisture and corrosion at the plugs impair the electrical contact. Voltage spikes, for example from a weak battery or a jump start, put additional strain on the electronics. Which cause is present only becomes clear through the examination.

How can you tell that the 89170-33T90 is defective?

A defect shows through the airbag warning light in the instrument cluster, which lights up at times or constantly. In addition there is a fault message in the instrument cluster, no connection to the diagnostic tool, and a fault memory that cannot be erased.

As long as these signs persist, airbags and seatbelt pretensioners may fail to deploy in an emergency. The light therefore reports the fault, and you have the system checked promptly.

Which vehicles is the 89170-33T90 fitted in?

The 89170-33T90 is fitted in these vehicles: Lexus ES AXZH60 (from 2018). Whether your car is among them is shown by a look at the list on this page and at the label on the unit.

Our data gives the following vehicles for this number:

• Lexus ES AXZH60 (from 2018)

Comparing the label is a check that the unit fits. Whether it is defective is only established by the fault memory, which you have read out before removal; a plug or a cable can also be the cause.

For the same vehicles, we also repair control units with the part numbers 89170-06820, 89170-06850, 89170-06880, 89170-33B90, 89170-33C30, 89170-33C50.

How does the repair of the 89170-33T90 work?

First have the fault memory read out and enclose the log, then disconnect the battery. Only after that remove the control unit. Then create a repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. Afterwards Airbag24 sends your unit back to you.

Processing at Airbag24 usually takes 3–4 working days. 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 89170-33T90 get to Airbag24?

You send the unit in as a parcel or book a UPS collection for an extra charge. The return after the repair is likewise made by UPS.

The printed repair order belongs in the parcel, and the unit needs a shock-proof box.