Conditions for Running the DTC

WARNING: This page is about a different car, the 2006 GMC Sierra, 2006 GMC Cab & Chassis Sierra, 2006 Chevrolet Silverado, and 2006 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

No AT VSS DTC P0502 or P0503.
No TFP manual valve position switch DTC P1810.
The system voltage is between 8-18 volts for more than 0.5 seconds.
TFP manual valve position switch is not indicating PARK or NEUTRAL.
The vehicle speed is greater than 26 km/h (16 mph).
The engine is running for more than 7 seconds.