Conditions for Setting the DTC: P1516
WARNING: This page is about a different car, the 2008 Suzuki Swift +, 2008 Pontiac Wave, and 2008 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects the difference between the actual throttle position, and the desired position is greater than 5 percent for 30 seconds.