Outline Of Diagnosis

Detect malfunctions of the thermostat function.

Judge as NG when any one of the following conditions is established.

• When the actual engine coolant temperature does not reach the maximum temperature necessary to perform other OBDII diagnosis and Σ (Estimated engine coolant temperature - actual engine coolant temperature) exceeded the predetermined value. (Judgment 1)
• When the actual engine coolant temperature does not reach the range within -11°C (-19.8°F) from the regulated temperature and Σ (Estimated engine coolant temperature - actual engine coolant temperature) exceeded the predetermined value. (Judgment 2)
• When the difference between the estimated coolant temperature and the actual engine coolant temperature exceeds the predetermined value, and Σ (Estimated engine coolant temperature - actual engine coolant temperature) exceeded the predetermined value. (Judgment 3)