Warm-Up Cycle

The PCM uses warm-up cycles to run some diagnostics, and to clear any diagnostic trouble codes (DTCs). A warm-up cycle occurs when the engine coolant temperature increases 22°C (40°F) from start-up. The engine coolant must also achieve a minimum temperature. The PCM counts the number of warm-up cycles in order to clear the malfunction indicator lamp (MIL). The PCM will clear the DTCs when 40 consecutive warm-up cycles occur without a malfunction.