Conditions for Setting the DTC

WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

The fuel tank vacuum is greater than 12 in H2O vacuum for 5 s before 10 L (2.6 gal) of purge volume.
OR
The fuel tank pressure (FTP) is less than -2.5 in H2O or more than +5 in H20 for 60 s after a cold start.
After setting the DTC for the first time, 2 L (0.5 gal) of fuel must be consumed before setting the DTC for the second time.