An ACDelco GM Original Equipment Engine Crankshaft Position Sensor monitors the position and rotational speed of the crankshaft, and is a GM-recommended replacement for your vehicle's original component. The signal from the crankshaft position sensor is used by the engine control module to determine fuel injection and ignition timing. This original equipment engine crankshaft position sensor has been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors.