Airbag control unit with part number 89170-53840

What does the airbag control unit 89170-53840 do?

For Lexus, the airbag control unit 89170-53840 controls the restraint system (SRS) and responds to the signals of the crash sensors. In an accident it decides within milliseconds which airbags and seatbelt pretensioners are triggered.

During operation it checks continuously whether the system works, and faults appear via the airbag warning light.

After an accident it stores crash data and locks itself.

Why does the control unit 89170-53840 fail?

Stored crash data is the most common cause of faults on the 89170-53840, even if no airbag was triggered. Further causes lie in the electronics: aged components, cold solder joints, moisture and corrosion on plug connectors, as well as voltage spikes.

A normal diagnostic tool cannot remove the crash data. Airbag24 removes it during the repair.

Ageing of components and cold solder joints reduce the reliability of the electronics. Moisture and corrosion wear on the plug connectors.

Voltage spikes, for example from a weak battery or jump-starting, are an additional load.

How can you tell that the 89170-53840 is defective?

The airbag warning light in the instrument cluster indicates a defect on the 89170-53840 when it stays on permanently or intermittently. Further signs are a fault message in the instrument cluster, a missing contact with the diagnostic tool and a fault memory that cannot be cleared.

• airbag warning light, permanently or intermittently
• fault message in the instrument cluster
• diagnostic tool without connection to the control unit
• fault memory that cannot be cleared

Airbags and seatbelt pretensioners may then fail to trigger in an emergency. Do not hesitate with the check.

Which vehicles is the 89170-53840 fitted in?

The 89170-53840 is found in these models: Lexus LS XF50 (from 2018).

Below you will find the list of models for this part number:

• Lexus LS XF50 (from 2018)

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

For the same vehicles, we also repair control units with the part numbers 89170-50K81, 89170-50K83, 89970-50090.

How does the repair of the 89170-53840 work?

First have the fault memory read out and attach the log. Then disconnect the battery and only then remove the 89170-53840. Then create the repair order online and send the unit in, packed securely.

Airbag24 examines the unit on the test bench, replaces defective components, erases stored crash data and carries out a functional test. Processing usually takes 3–4 working days there. Afterwards your own unit goes back.

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 89170-53840 get to Airbag24?

You send the control unit 89170-53840 as a parcel to Airbag24 or book a UPS collection for an extra charge. The return to you after the repair is made by UPS.

Put the printed repair order and a shockproof packed unit into the parcel.