Circuit/System Description
WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) uses the crankshaft position sensor and the camshaft position sensor pulses to monitor the correlation between the crankshaft and the camshaft position.