DTC P0125: Closed Loop Temp Not Reached: Testing
NOTE:
If an Engine Coolant Temperature (ECT) sensor DTC is also stored, diagnose ECT sensor DTC first. Ensure ECT sensor terminals and related PCM terminals are free from corrosion and damage.
NOTE:
To diagnose this DTC, manufacturer recommends allowing vehicle to sit overnight in order to have a totally cold engine. Extremely cold ambient outside temperatures may have caused this DTC to set.
- Allow engine to cool. Check cooling system for proper coolant level and condition. Repair any coolant leaks and add necessary amount of coolant as necessary. If coolant level is okay and coolant is in good condition, go to next step.
- Turn ignition on. Using scan tool, read ENG COOLANT TMP DEG value. If engine was allowed to sit overnight, scan tool temperature value should be near ambient air temperature. If engine coolant temperature is more than 180°F (82.2°C), allow engine coolant temperature to cool down to 150°F (65.5°C) before proceeding. If engine coolant temperature is 150°F (65.5°C) or less, start engine. Using scan tool, monitor ENG COOLANT TMP DEG until engine coolant temperature reaches 180°F (82.2°C). Temperature value should increase smoothly from start-up to normal operating temperature. Also monitor actual coolant temperature with a thermometer. As engine warms up to normal operating temperature, actual coolant temperature should be relatively close to temperature reading on scan tool. Monitor coolant temperature and note when thermostat opens. Thermostat should open at about 190°F (87.7°C). Replace thermostat as necessary. If thermostat opens as specified, test is complete.