Hello Chad, the camshaft position actuator is the device that sends oil pressure to an actuator located at the front of each intake camshaft, this system allows for variable cam timing and eliminates the need for an exhaust gas recirculation system. It allows for a certain amount of valve overlap at varying engine speeds to leave just a small amount of exhaust gas in the cylinder for the next combustion event. By doing this the combustion chamber temperature will reduce slightly and help control one type of tailpipe emmisions known as Oxides of Nitrogen. When the actuator has a fault or wiring to the sensor has a fault it will set this diagnostic trouble code. To pinpoint what has actually failed you must follow the workshop manual diagnostic pinpoint test, which I have attached for you. Diagnostic code p0020 is for the actuator on the drivers side of the engine (BANK 2), the actuator you will be testing is protruding through the drivers side rocker cover.