When Monitored
This diagnostic runs once per ignition cycle when the following conditions are met:
- Shortly after an initial engine start.
- The difference between the coolant temperature and ambient air temperature is less than 15°C (59°F) at initial engine start.
- The engine coolant temperature recorded at the last engine shut down was above 83°C (181.4°F).
- If the previous engine shut down temperature was not above this value, the shut down diagnostic will not be performed during this ignition cycle.
- If the above monitoring conditions are met, the PCM uses the engine coolant temperature drop to calculate a minimum ignition off time threshold. It then compares the previous ignition off time to the calibrated minimum threshold.