Conditions for Running the DTC

WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The engine has been running for a length of time that is determined by startup coolant temperature. The length of time ranges from 5.5 minutes at less than -30° C (-22° F) to 10 seconds at more than 30° C (86° F).
DTC P0121, P0122, P0123 are not set.
The throttle angle is less than 1 percent when the engine speed is less than 1,200 RPM.
OR
The throttle angle is more than 12.5 percent when the engine speed is more than 1,200 RPM.