volvo xc90 Available Here. Camshaft position sensors play an important role in the functioning of your automobile’s engine. They sense and record the position and speed of your camshaft, and transmit this information to your vehicle’s engine control module. Using that data, the computer regulates the timing of the fuel injection and ignition. When camshaft position sensors develop a fault, you’ll see common symptoms such as rough idling, stalling and a reduction in engine power. Another telltale sign is the “check engine” light on your dash.