Circuit/System Description
WARNING: This page is about a different car, the 2009 Saturn Vue. 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 intake and exhaust camshaft position (CMP) sensor information to monitor the correlation between the crankshaft, intake, and exhaust camshaft position.