Your vehicle has electronic power steering assist.
This means instead of having a power steering pump that provides hydraulic assist power steering, your vehicle has an electric motor that provides steering assist.
This motor operates from the signal it receives from the steering wheel angle sensor.
https://www.rockauto.com/en/moreinfo.php?pk=7988252&cc=3308940&jsn=371
This sensor may be beginning to fail, causing your problem.
Tester