A crankshaft sensor is part of a computerized engine management system in many modern cars. This sensor typically works in conjunction with the camshaft position sensor to report data to a computer that controls the engine's ignition timing.
The placement of the crankshaft sensor in a vehicle can cause it to fail due to oil leaks or heat. This generally causes a vehicle to release a trouble code that indicates failure of the crankshaft position sensor. Vehicles that have a non-operational crankshaft sensor can show various symptoms, such as a misfiring engine, an active check engine light or failure to start.