초록 ▼

A method for monitoring engine coolant warm-up behavior utilizing a model-based algorithm which provides a moving threshold for accumulated air or accumulated fuel entering into the engine. The algorithm allows for coolant temperature monitoring under a wide range of transient and steady state drivi

A method for monitoring engine coolant warm-up behavior utilizing a model-based algorithm which provides a moving threshold for accumulated air or accumulated fuel entering into the engine. The algorithm allows for coolant temperature monitoring under a wide range of transient and steady state driving conditions while maintaining safeguards that prevent a false detection. The accumulated air (or fuel) delivered to the engine during the warm-up interval is used to represent the total heat generated by the engine during the warm-up interval. A time-varying moving calculated accumulated air threshold is therefore defined which can deliver accurate pass-fail decisions in conjunction with a predetermined target temperature.

대표청구항 ▼

[ What is claimed is:] [1.] A method for diagnosing warm-up behavior of a cooling system of an internal combustion engine of a vehicle upon start of the engine, comprising the steps of:a) setting a target temperature for a coolant of a cooling system of an engine;b) measuring a start-up temperature

[ What is claimed is:] [1.] A method for diagnosing warm-up behavior of a cooling system of an internal combustion engine of a vehicle upon start of the engine, comprising the steps of:a) setting a target temperature for a coolant of a cooling system of an engine;b) measuring a start-up temperature of the coolant;c) measuring engine run time since engine start;d) determining a present ambient air temperature;e) calculating a present threshold amount of energy needed to be produced by the engine to raise the coolant temperature from the start-up temperature to the target temperature;f) determining a present actual amount of energy produced by the engine since engine start;g) comparing present coolant temperature to the target temperature;h) comparing the present threshold amount of energy to the present actual amount of energy; andi) continuously repeating steps c) through h);wherein a pass report is generated when the present coolant temperature is at least equal to the target temperature, and the present threshold amount of energy is at least equal to the present actual amount of energy, and the engine run time is less than a predetermined maximum engine run time.