Airbag control unit with part number 89170-50L71

What does the airbag control unit 89170-50L71 do?

The airbag control unit 89170-50L71 is the switching point of the restraint system (SRS) in Lexus vehicles. It processes the signals from the crash sensors and, in an accident, triggers the airbags and seatbelt pretensioners intended for it within milliseconds.

The unit continuously monitors the sensors, wiring and actuators and reports faults via the airbag warning light.

After an accident, it stores crash data and locks itself.

Why does the control unit 89170-50L71 fail?

Stored crash data is the most common cause, even when no airbag has deployed. Other causes include aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes from a weak battery or jump-starting.

Crash data cannot be erased with a normal diagnostic tool, not even after several attempts.

The other causes tend to develop over a long period. Moisture and corrosion attack the contacts, and cold solder joints can come loose.

How can you tell that the 89170-50L71 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, possibly accompanied by a fault message. If the diagnostic tool cannot connect to the control unit, or the fault memory cannot be cleared, there is a further sign.

The warning light is therefore a clear signal that you should take seriously. In an emergency, the airbags and seatbelt pretensioners may fail to deploy. Please have the finding checked promptly.

Which vehicles is the 89170-50L71 fitted in?

Your vehicle documents will tell you whether your car is one of them. The control unit 89170-50L71 is fitted in these vehicles: Lexus LS XF50 (from 2018).

The following list shows the vehicles that Airbag24 has assigned to this part number.

• Lexus LS XF50 (from 2018)

Firstly, compare the part number on the label of the removed unit with this page. This only confirms whether it is the right unit, not whether it is defective. Secondly, have the fault memory read out in advance, because only this log 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 89170-50L71 work?

Have the fault memory read out, attach the log and disconnect the battery before removing the control unit. Then create a repair order online and send the carefully packed unit in. Airbag24 usually checks, repairs and tests it within 3–4 working days.

This order protects you during removal, so please follow it.

At Airbag24, the unit is checked on the test bench, components are replaced where necessary, and stored crash data is deleted. A function test completes the work, after which 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 89170-50L71 get to Airbag24?

You can either send the unit as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Put the printed repair order into the parcel and pack the control unit shockproof.