Conditions for Setting the DTC

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The control module detects a leak in the EVAP system that is greater than a calibrated amount.
The control module must complete several EONV tests before the diagnostic can turn the MIL ON or OFF.