Conditions for Setting the DTC
WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects that the HO2S 2 voltage is less than 630 mV for greater than 100 seconds, then an intrusive test is performed. The ECM will enrich the fuel mixture 2 percent per second and then wait for 10 seconds at 20 percent. If the ECM detects that the HO2S 2 voltage is less than 630 mV during the intrusive test for greater than 4 second or for a cumulative of 30 seconds, the DTC sets.