An externally mounted electric coolant pump is installed on the front right side of the engine block, to enhance the heating and cooling of the engine and this pump can work even when the engine is off. In cold start conditions, a low flow rate is provided to fast track the warm up whilst a high flow rate including with the engine not running is used for fast cool down allowing improved efficiency and durability of the engine. The basic operation and speed of the pump is regulated by the DME which employs the engine load, operation range, and several temperature sensors for regulating it. Furthermore, the electric coolant pump can diagnose and memorize some conditions of the error, including the problem like the impeller speed deviance, stiff operation or blockage by foreign matters, too high or too low ratio of the coolant/water, and the appearance of the air in the cooling system.