Crankshaft Position Sensor
WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
If there is a fault in the CKP sensor circuits, the ignition system can malfunction. See DTC P0335: CKP SENSOR CIRCUIT under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - 1.8L VIBE article.