Electric power steering - sensor calibration function

Hi.

For an electric power steering system, if the steering goes stiff then I would put that down to a faulty motor OR motor circuit - battery & alternator included.

Another technician said that the steering angle sensor may need to be calibrated. Is this correct?

From my understanding, an uncalibrated steering angle sensor might affect the self centering ability of the steering mechanism but it's not going to cause the steering wheel to go stiff?

I'd like to hear what others think...