Airbag control unit with part number 89170-33N21

What does the airbag control unit 89170-33N21 do?

The airbag control unit 89170-33N21 belongs to the restraint system (SRS) of Lexus and is its control centre. From the messages of the crash sensors it determines whether an accident has occurred and, in an emergency, triggers the appropriate airbags and seatbelt pretensioners. After a crash the unit stores crash data and locks itself.

While driving it checks the system for faults without interruption. If a fault is found, it is shown via the airbag warning light in the instrument cluster.

The decision in an accident is made in milliseconds, so the electronics work without delay. The occupants rely on exactly this reaction time.

Why does the control unit 89170-33N21 fail?

The most common cause is crash data stored after an accident, even if no airbag was deployed; a normal diagnostic tool cannot erase it. Further causes in brief: aged components, cold solder joints, moisture and corrosion, and voltage spikes.

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

Whether one of these causes is present cannot be said reliably from the outside.

The examination of the unit shows which cause actually led to the failure.

How can you tell that the 89170-33N21 is defective?

The airbag warning light in the instrument cluster lights up permanently or only intermittently, and an error message appears in the instrument cluster. The diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared.

If you see these signs, have the vehicle checked promptly. The light is therefore not a cosmetic fault but a warning.

In an emergency the airbags and seatbelt pretensioners may not deploy when the control unit is faulty.

Which vehicles is the 89170-33N21 fitted in?

The 89170-33N21 is fitted in these vehicles: Lexus ES AXZH60 (from 2018).

The list shows the vehicles individually, so you can find your own model directly:

• Lexus ES AXZH60 (from 2018)

Compare the part number on the label of the removed unit with this page; this only ensures that it is the right unit. Have the fault memory read out beforehand, because only this record shows whether the control unit is defective or whether a plug or a cable is behind the fault.

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 89170-33N21 work?

First have the fault memory read out and attach the log, then disconnect the battery and only then remove the control unit. Next create a repair order online and send in the well-packed unit. On the test bench Airbag24 examines the unit, repairs defective components, erases stored crash data and carries out a function test; processing usually takes 3–4 working days.

Afterwards your own 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 89170-33N21 get to Airbag24?

Either you send the unit as a parcel, or you book a UPS collection for an extra charge. After the repair UPS brings it from Airbag24 back to you.

Pack the printed repair order along with it, and pack the unit shock-proof.