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.

DTCs P0502 or P0503 are not set.
The engine run time is more than 45 seconds.
The vehicle speed sensor (VSS) indicates that vehicle speed is more than 40 km/h (25 mph).