Conditions for Setting the DTC: P2101
WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects a 4-50 percent difference between the commanded and the actual throttle plate position, dependent upon the rate of commanded throttle movement. The condition exists, then a 5 second delay for MIL ON.