I have an alldata account which confirms there is in fact a steering angle sensor, but there is only a procedure describing how to diagnose whether it is working. No mention of resetting or recalibrating.
The angle sensor is only an input to the ECU or a control module, typically only used for TC related functions. It doesn't have any effect on alignment or pulling.
I don't know anything about calibrating one, but I would imagine it is a sensitive measure, seeing as the sensor operates at a degree of sensitivity.
I think the steering sensor in this electrical system also allows the steering system to provide an "on center" feel for steering "feedback". If you are on a perfectly level surface and set a curve and turn the steering loose it should move to the straight ahead position. Some of that is from caster angle but I think the steering angle sensor is also involved.
Constantly indicates 0 until the steering wheel angle neutral position determination by the DSC HU/CM is completed.
The steering wheel angle neutral position determination by the DSC HU/CM is completed when the vehicle is driven in a straight line at a speed of 20 km/h or more for several seconds.