2007 Chevy Colorado Cam Shift Sensor

Hello-
Check engine light has been on and when I checked the code it came up as the cam shift sensor. How do I know if it is the uper or lower and where are they located? I’m fairly mechanical so can I do this myself?

@Zeppelin

Please post the EXACT fault code, please. Not your interpretation

You have 2 cams. Exhaust and Intake