Warm-Up Cycle
WARNING: This page is about a different car, the 2005 GMC Canyon and 2005 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
The PCM uses warm-up cycles to run some diagnostics and to clear any DTCs. A warm-up cycle occurs when the engine coolant temperature increases 22°C (40°F) from the start-up temperature. The engine coolant must also achieve a minimum temperature of 71°C (160°F). The PCM counts the number of warm-up cycles in order to clear the MIL. The PCM will clear the DTCs when 40 consecutive warm-up cycles occur without a malfunction.