Conditions for Running the DTC

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The ignition is ON.
The engine is turning faster than 50 RPM.
DTC P0340 runs continuously when the above conditions are met.
DTCs P0335, P0336, P0642, or P0643 are not set.