Conditions for Setting the DTC
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The ECM does not detect a change of 3 L (0.7925 gal), in both the primary and the secondary fuel level sensors, with the secondary pump commanded ON for 200 seconds.