Conditions for Running the DTC: P0450

WARNING: This page is about a different car, the 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

The engine is running.
The estimated ambient air temperature is warmer than -7°C (+19.4°F).
The EVAP canister vent valve has been open for more than 3 seconds.
The vehicle speed is less than 29 km/h (18 mph).
DTC P0450 runs continuously when the above conditions have been met.