Crankshaft Position Sensor
WARNING: This page is about a different car, the 2004 Kia Rio. However, it is still accessible from the selected car via links, so may be relevant.
The Crankshaft Position (CKP) Sensor is used to signal the ECM when a spark and/or fuel injection event required. The output from this sensor, in conjunction with the Camshaft Position Sensor signal, is used to determine whether spark or fuel is required in a particular cylinder. The engine will not start without a CKP Sensor signal to the ECM.