Conditions for Setting the DTCs (w/LLT)
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
The ECM determines that the length of time for a primary HO2S to switch from lean to rich and back to lean, which is called a switching cycle, has exceeded a predetermined threshold. The condition exists for 2.5 cycles out of a 20 cycle test sample.