CUSTOMER CONCERN Customer states the check-engine light is on and DTC P0128 is stored. CAUSE Cold-soak temperature data and cooling-system checks confirmed the engine coolant thermostat was not maintaining the specified regulating temperature. CORRECTION Remove and replace engine coolant thermostat. Refill and bleed engine cooling system. Clear DTC P0128.

CUSTOMER CONCERN Customer states the check-engine light is on with DTC P0128. CAUSE Cold-soak temperature comparison confirmed the engine coolant thermostat was not regulating temperature correctly. CORRECTION Remove and replace engine coolant thermostat. Refill and bleed engine cooling system.

CUSTOMER CONCERN The check-engine light was on with DTC P0128. CAUSE The engine coolant thermostat was not regulating coolant temperature correctly, so the engine did not reach the expected temperature. CORRECTION The engine coolant thermostat was replaced.

CUSTOMER CONCERN The check-engine light was on with DTC P0128. CAUSE The engine coolant thermostat was not maintaining the expected regulating temperature. CORRECTION The engine coolant thermostat was replaced.