Circuit/System Description
WARNING: This page is about a different car, the 2008 Pontiac G5 and 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) uses the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor information to monitor the correlation between the crankshaft and camshaft position.