An ACDelco Professional, premium aftermarket Engine Camshaft Position Sensor is the high quality replacement ideal for many vehicles on the road today. It monitors the rotational position of the camshaft(s). It provides a signal to the engine control module, which compares the camshaft position with the crankshaft position to determine ignition and fuel injection timing. This premium aftermarket replacement engine camshaft position sensor is manufactured to meet your expectations for fit, form, and function.