Airbag control unit with part number 89170-33C40

What does the airbag control unit 89170-33C40 do?

The airbag control unit 89170-33C40 is the central control unit of the restraint system (SRS) for Lexus. It evaluates the signals from the crash sensors and decides in an accident within milliseconds which airbags and seatbelt pretensioners are triggered. After an accident it stores crash data and locks itself.

While driving, the unit monitors the restraint system continuously. If it detects a fault, it shows it via the airbag warning light in the instrument cluster.

Why does the control unit 89170-33C40 fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes. Airbag24 erases the crash data during the repair.

A normal diagnostic tool cannot erase this data, even if the vehicle drives again after the accident.

The other causes lie in the electronics themselves. Components age, solder joints can go cold, and moisture or corrosion at plug connections disturb the contact.

Voltage spikes additionally stress the electronics, for example when the battery is weak or a jump start is given.

How can you tell that the 89170-33C40 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, and an error message may appear in the instrument cluster. The diagnostic tool then gets no connection to the control unit 89170-33C40, and the fault memory cannot be cleared.

If the warning light comes on only intermittently, that is also a sign of a fault. Pay particular attention to whether it goes out after starting or stays on permanently.

As long as a fault is stored, airbags and seatbelt pretensioners may fail to deploy in an emergency. A prompt check is therefore worthwhile, even if the vehicle still drives without problems.

Which vehicles is the 89170-33C40 fitted in?

The 89170-33C40 is fitted in these Lexus vehicles: Lexus ES AXZH60 (from 2018). The assignment is based on our data for this part number.

The vehicles for which we hold this part number are listed here:

• Lexus ES AXZH60 (from 2018)

Compare the part number on the label of the removed unit with this page. This only shows you that you have the right unit, nothing more. Whether the control unit itself is defective, or whether a plug or cable is the cause, is shown only by the fault memory once it has been read out.

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 89170-33C40 work?

First have the fault memory read out and attach the log. Then disconnect the battery and only afterwards remove the control unit. Processing at Airbag24 takes 3–4 working days.

Then create a repair order online and send the well-packed unit.

Airbag24 checks it on the test bench, replaces defective components, erases stored crash data and runs a function test. Afterwards the unit goes 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 89170-33C40 get to Airbag24?

You send the control unit 89170-33C40 in as a parcel, or you book a UPS collection for an extra charge. After the repair Airbag24 returns it by UPS.

Put the printed repair order in the parcel and pack the unit shockproof.