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 raises 22 degrees C (40 degrees F) from start-up. The engine coolant must also achieve a minimum temperature of 71 degrees C (160 degrees F). The PCM counts the number of warm-up cycles in order to clear the Malfunction Indicator Lamp (MIL). The PCM will clear the DTC(s) when 40 consecutive warm-up cycles occur without a malfunction.