Airbag control unit with part number 89170-33N31

What does the airbag control unit 89170-33N31 do?

The airbag control unit 89170-33N31 is the central control unit of the restraint system (SRS) for Lexus. It evaluates the signals from the crash sensors, determines in an accident within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system without interruption. It indicates faults via the airbag warning light.

Monitoring runs in the background as soon as the ignition is switched on. The unit also checks the connections to sensors and triggers.

After an accident, the unit stores crash data and locks itself. The lock is only lifted by the repair.

Why does the control unit 89170-33N31 fail?

The most common cause of a 89170-33N31 fault is crash data stored after an accident, even if no airbag was triggered. Further causes include age-related damage, dry solder joints, moisture and corrosion on plug connections, and voltage spikes.

Crash data cannot be deleted with an ordinary diagnostic tool. At Airbag24 it is deleted during the repair.

The further causes at a glance:

• ageing electronic components
• dry solder joints
• moisture and corrosion on plug connections
• voltage spikes, for example from a weak battery or jump-starting

How can you tell that the 89170-33N31 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently when the 89170-33N31 has a defect. In addition, there is a fault message in the instrument cluster, no connection to the diagnostic tool, and a fault memory that cannot be cleared.

A defect is therefore not hidden but indicated by the warning light. In an emergency, airbags and seatbelt pretensioners may not trigger in this condition.

For that reason, a check should be carried out without delay.

Which vehicles is the 89170-33N31 fitted in?

The comparison with the vehicle list shows whether your own car is affected. The control unit 89170-33N31 is fitted in these vehicles: Lexus ES AXZH60 (from 2018).

These vehicles are recorded for this number:

• Lexus ES AXZH60 (from 2018)

Compare the part number on the label of the removed unit with this page. This only confirms that it is the correct unit; the comparison says nothing more. Have the fault memory read in advance, because only this log shows whether the control unit itself is defective or whether a plug or cable is 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 89170-33N31 work?

Processing the 89170-33N31 at Airbag24 usually takes 3–4 working days. In advance, have the fault memory read and attach the log to the parcel. Then disconnect the battery, remove the control unit and create a repair order online before you send it in.

At the test bench, Airbag24 examines the unit, repairs defective components and deletes stored crash data. A function test follows before your own unit is sent back.

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 89170-33N31 get to Airbag24?

You send the parcel to Airbag24 yourself, or you book a UPS collection for an extra charge. The 89170-33N31 is returned by UPS after the repair.

The printed repair order is enclosed with the parcel, and the unit is packed shock-resistant.