The steering angle sensor (SAS) is a vital part of the ESC system that measures the steering wheel position angle and rate of turn.
When wheel alignment gets done or the actual physical direction the steering is set at, and the steering angle sensor’s last calibration is different enough to cause the DSC (dynamic stability control) ECU confusion in certain conditions.
Then you need to reset the steering angle sensor so that its straight ahead reading in software corresponds with the physical straight ahead position. BMW INPA diagnostic interface can be used to obtain these data in degrees.
Install and open INPA diagnostic software (various instructions on forums)
Select vehicle as E46
Select steering angle sensor
Hit F5 to read status
Hit F4 and the system will show the general status
You will able to view the current steering angle sensor is calibrated to close to zero deg. when the physical steering is pointed straight ahead
If the steering angle sensor calibration value is not extremely close or exact, you need to reset it.
Go to main menu and select E46 again
Click SHIFT+F4 buttons at the same, the system will display the compensation routines.
Click F1 button to reset the steering angle sensor
Go back to steering angle sensor menu to view the current status. The calibrated value should go down to zero. The procedure is complete and then you can clear the error codes or do other coding options.