Airbag control unit with part number 89170-33N91

What does the airbag control unit 89170-33N91 do?

In an emergency, the airbag control unit 89170-33N91 decides which airbags and seatbelt pretensioners are triggered, and evaluates the crash sensors for this purpose. It forms part of the restraint system (SRS) of Lexus. It reports faults via the airbag warning light.

While driving, the unit monitors the connections and circuits of the system and records any deviations.

After an accident, it stores crash data and locks itself.

Why does the control unit 89170-33N91 fail?

Stored crash data after an accident is the most common cause with the 89170-33N91, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Other causes include aged electronics, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data is created as soon as the unit detects an accident, regardless of whether an airbag fires.

Cold solder joints and corrosion at plugs affect the connections, while voltage spikes affect the power supply.

How can you tell that the 89170-33N91 is defective?

The airbag warning light on the 89170-33N91 comes on permanently or intermittently, and a fault message appears in the instrument cluster. The diagnostic tool finds no connection to the control unit, the fault memory cannot be erased, and then airbags and seatbelt pretensioners may fail to trigger in an emergency.

The light indicates the defect even when the vehicle otherwise behaves normally.

Note how the message occurs before you begin the repair.

Which vehicles is the 89170-33N91 fitted in?

The control unit 89170-33N91 is found in these vehicles: Lexus ES AXZH60 (from 2018).

The list follows for comparison:

• Lexus ES AXZH60 (from 2018)

If the part number on the label of the removed unit matches this page, you can be sure it is the right unit. The decisive factor for the cause, however, is the fault memory, which must be read out before removal.

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 89170-33N91 work?

First have the fault memory of the 89170-33N91 read out and enclose the log. Then disconnect the battery and only then remove the control unit. Next, create a repair order online and send the unit in. The processing time at Airbag24 is usually 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, deletes crash data and then carries out a function test.

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 89170-33N91 get to Airbag24?

The route to Airbag24 for the 89170-33N91 is by parcel or by UPS collection, which is booked for an extra charge; after the repair, UPS brings the unit back.

The printed repair order goes into the parcel, and the unit is packed shock-proof.