Conditions For Running DTC P0503

WARNING: This page is about a different car, the 2002 GMC Cab & Chassis Sierra and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

DTC will run under the following conditions:

No TFP manual valve position switch DTC P1810.
The engine is running greater than 400 RPM for greater than 7 seconds.
The system voltage is between 8-18 volts.
No TFP manual valve position switch changes for greater than 6 seconds.
No output shaft speed increase greater than 250 RPM within 2 seconds.