Airbag control unit with part number 89170-33E90

What does the airbag control unit 89170-33E90 do?

The 89170-33E90 is the central control unit of the restraint system (SRS) for Lexus. It evaluates the signals from the crash sensors, decides in an accident within milliseconds on the triggering of airbags and seatbelt pretensioners, and monitors the system continuously. After an accident it stores crash data and locks itself.

The system checks itself, and a detected fault is reported via the airbag warning light.

Triggering must not be delayed in an emergency. That is why faultless function is so important for the safety of the occupants.

Why does the control unit 89170-33E90 fail?

Stored crash data is the most common cause: it remains in the unit after an accident even if no airbag was triggered, and an ordinary diagnostic tool cannot clear it. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

The other causes tend to be gradual. Aged components lose reliability, and moisture corrodes contacts.

Voltage spikes put additional strain on the electronics and can leave damage behind.

How can you tell that the 89170-33E90 is defective?

A defect shows when the airbag warning light in the instrument cluster lights up, a fault message appears, the diagnostic tool cannot establish a connection to the control unit, or the fault memory cannot be cleared. In this case airbags and seatbelt pretensioners may fail to trigger in an emergency.

The signs in detail:

• airbag warning light that lights up permanently or intermittently
• fault message in the instrument cluster
• missing connection of the diagnostic tool to the control unit
• fault memory that cannot be cleared

The warning light is the most important signal, because it shows the fault as soon as the system detects it.

Which vehicles is the 89170-33E90 fitted in?

The 89170-33E90 is fitted in these vehicles: Lexus ES AXZH60 (from 2018).

The following vehicles are assigned to this part number.

• Lexus ES AXZH60 (from 2018)

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit. Whether the control unit is defective or a plug or cable causes the fault is shown only by reading out the fault memory. Have it 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 89170-33E90 work?

First have the fault memory read out and attach the log, then disconnect the battery and remove the control unit. Then create an online repair order and send the unit in well packed. Airbag24 needs 3–4 working days as a rule for testing, repairing and checking.

The sequence is mandatory for your safety. The control unit may only be removed once the battery is disconnected.

Defective components are repaired at Airbag24, stored crash data is deleted, and a function test follows. 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 89170-33E90 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends the unit back by UPS.

Enclose the printed repair order in the parcel and pack the control unit shock-proof.