Airbag control unit with part number 89170-76440

What does the airbag control unit 89170-76440 do?

The airbag control unit 89170-76440 forms the central control unit of the restraint system (SRS) for Lexus. It processes the crash sensor data, decides in an accident within fractions of a second on the triggering of airbags and seatbelt pretensioners, and checks the system continuously. It reports faults via the airbag warning light.

The sensor data flow continuously into this evaluation. As a result, the decision is already available in an emergency.

After an accident the unit stores crash data and locks itself. A reported fault requires prompt checking, because the restraint system is only fully available when the control unit works properly.

Why does the control unit 89170-76440 fail?

The most common cause at 89170-76440 is stored crash data after an accident, even if no airbag has deployed. A standard diagnostic tool cannot erase it. Further causes are ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data remain in the unit after the accident, even if the restraint devices were left untouched. The diagnostic tool has no means of removing them.

Electronic components age, and solder joints can go cold. Moisture and corrosion at plug connections lead to contact problems, and voltage spikes from the vehicle electrical system, for example from a weak battery or a jump-start, also affect the electronics. The check shows which cause applies.

How can you tell that the 89170-76440 is defective?

An airbag warning light in the instrument cluster that stays on permanently or intermittently, an error message in the instrument cluster, a missing connection to the diagnostic tool and a fault memory that cannot be cleared indicate a defect on the 89170-76440.

With these signs, airbags and seatbelt pretensioners may fail to deploy in an emergency. The warning applies regardless of how unremarkably the vehicle runs in everyday use.

The warning light shows the defect, and a check creates clarity before the system is needed in an emergency.

Which vehicles is the 89170-76440 fitted in?

The control unit 89170-76440 is fitted in these vehicles: Lexus UX MZAA10 (from 2018).

The allocation covers the following models:

• Lexus UX MZAA10 (from 2018)

Compare the part number on the label of the removed unit with this page, because that only confirms that you have the right unit. Also have the fault memory read out beforehand, because only the log shows whether the control unit is defective or whether a plug or cable is the cause.

How does the repair of the 89170-76440 work?

For the 89170-76440, first have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit. Then create a repair order online and send in the unit, well packed. Airbag24 usually needs 3–4 working days for this.

Airbag24 checks the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. 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 89170-76440 get to Airbag24?

You send the control unit 89170-76440 in as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back by UPS.

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