Airbag control unit with part number 89170-50K30

What does the airbag control unit 89170-50K30 do?

The airbag control unit 89170-50K30 is the restraint system (SRS) control unit in Lexus. It processes the signals from the crash sensors continuously and, in an emergency, decides within milliseconds which airbags and seatbelt pretensioners are triggered. After an accident it stores crash data and locks itself.

Outside of an accident the unit checks the system continuously for faults. If a fault is found, it is shown via the airbag warning light in the instrument cluster.

The crash data is a record of the accident from the control unit's point of view. They initially remain stored in the unit.

Why does the control unit 89170-50K30 fail?

The most common cause in control unit 89170-50K30 is crash data stored after an accident, even if no airbag has deployed. Aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes are also possible causes.

Diagnostic tools of the usual scope cannot erase crash data. Airbag24 erases it during the repair, so that no old entries remain afterwards.

The other causes concern the electronics and the connections. Moisture and corrosion disturb plug connections, cold solder joints and aged components can cause faults that the fault memory displays. Voltage spikes, for example from a weak battery or jump-starting, put additional stress on the electronics.

How can you tell that the 89170-50K30 is defective?

A defect in the 89170-50K30 can be recognised by the airbag warning light in the instrument cluster, which lights up permanently or intermittently. A fault message in the instrument cluster, a diagnostic tool that cannot connect to the control unit, and a fault memory that cannot be cleared also appear.

With such a defect, airbags and seatbelt pretensioners may not be able to deploy in an emergency. The warning light displays the fault, and that is exactly its purpose; a prompt check is therefore advisable.

Which vehicles is the 89170-50K30 fitted in?

The papers in the vehicle registration document show whether your car is meant. The airbag control unit 89170-50K30 is fitted in these vehicles: Lexus LS XF50 (from 2018).

The list below shows the vehicles that we know of for this control unit.

• Lexus LS XF50 (from 2018)

Compare the label on the removed unit with this page, because that shows whether it is the right unit. Have the fault memory read out beforehand, because only this result shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 89170-50K81, 89170-50K83, 89170-50L00, 89170-50L03, 89170-53790, 89170-53820.

How does the repair of the 89170-50K30 work?

First have the fault memory read out, then disconnect the battery and only then remove control unit 89170-50K30. Afterwards you create a repair order online, enclose the log and send in the unit well packed. At Airbag24 processing usually takes 3–4 working days.

Airbag24 examines the unit on the test bench. Defective components are replaced, the crash data is erased and a function test is carried out. Afterwards your own unit is returned 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 89170-50K30 get to Airbag24?

You hand in control unit 89170-50K30 as a parcel or have it collected by UPS for an extra charge. After the repair UPS brings your own unit back to you.

Put the printed repair order into the parcel and pad the control unit so that nothing gets damaged.