Fault Diagnosis Method of Thermostat

Abstract

The invention discloses a thermostat fault diagnosis method, which comprises the following steps: confirming whether a flow cut-off valve is equipped in the vehicle through a controller; if it is determined that the flow cut-off valve is equipped in the vehicle, then diagnosing the flow cut-off valve; And if it is determined that the diagnosis of the flow shutoff valve is ended, the thermostat is diagnosed to determine whether the thermostat is malfunctioning.

Description

technical field [0001] The invention relates to a fault diagnosis method for a vehicle thermostat. Background technique [0002] The statements in this Background section are intended only to provide background information related to the present disclosure and may not constitute prior art. [0003] In general, a cooler is a device that cools an engine to prevent the engine from overheating and maintain the engine at an operating temperature. The cooler has an air-cooled type that uses outside air to directly cool the outside of the engine, and a water-cooled type that circulates cooling water into the engine to cool the engine. [0004] Such as figure 1 As shown, the water-cooled cooler is configured to include a water jacket 30 configured to surround a cylinder 10 and a combustion chamber 20, a water pump 40 for pumping water into the cylinder 10, a pump for transferring heat of high-temperature cooling water to outside air to cool the cooling water. The radiator 50, the...

AI Technical Summary

Problems solved by technology

[0008] However, when the valve is opened at a temperature lower than a predetermined temperature due to a malfunction of the thermostat, the cooling water is continuously cooled by the radiator, and thus the amount of heat loss due to the heat generated by combustion increases due to being cooled, thereby reducing the engine's performance. Thermal efficiency, because the temperature of the cooling water is low, the ECU that controls the fuel injection amount based on the temperature of the cooling water increases the fuel injection amount to increase power consumption, and produces a mixture that makes gasoline in the cylinder insufficiently atomized, dilutes the engine oil with gasoline, and promotes cylinder wear

In addition, a relatively larger amount of exhaust gas is generated than under normal conditions, which affects the performance of other self-diagnostic devices (oxygen sensor diagnosis, catalyst abnormality diagnosis, exhaust gas recirculation device diagnosis, boil-off gas system leak diagnosis, etc.)

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