Conditions for Setting the DTC
WARNING: This page is about a different car, the 2008 Suzuki Swift +, 2008 Pontiac Wave, and 2008 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) detects that the HO2S voltage is less than 350 mV and the air/fuel ratio is less than 13.5:1 during PE mode.