The crankshaft sensor on the Mitsubishi Eclipse is located near the crankshaft pulley. It sends a signal, via voltage, to the computer, signaling the location of the crankshaft and engine speed. If the crankshaft sensor malfunctions, the vehicle may or may not run, depending on the year and the type of electronic control module functions it has. Some Engine Control Modules, especially the ECMs in newer cars have a “limp home” mode where the computer reverts to the last known good setting so you can get the Eclipse home. You should change the crankshaft sensor if you notice decreased engine performance and higher fuel consumption in your Eclipse.
Disconnect the negative battery cable with a wrench and set it aside, ensuring that it doesn’t touch metal. Unplug the sensor’s wiring harness connector.