Circuit/System Description
WARNING: This page is about a different car, the 2006 Chevrolet Monte Carlo and 2006 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) compares actual throttle position (TP) to an expected throttle position based on engine load, air flow and speed. The ECM determines engine load and air flow based on inputs from the mass air flow (MAF) and the manifold absolute pressure (MAP) sensors. The ECM monitors the engine air flow, and throttle position for errors.