Conditions for Setting the DTC
WARNING: This page is about a different car, the 2008 Pontiac G5 and 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects an open, short to ground, or a short to voltage on the high control circuit or an open on the low reference circuit for more than 0.25 second.