Conditions for Running the DTC

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0335, P0336, P0340, P0341, P0641, or P0651 is not set.
The engine is running.
The engine speed is less than 2,000 RPM.
The CMP actuator is in the parked or home position.
The DTC runs continuously when the above conditions are met.