Why does the vehicle have high idle speed during cold start in summer?

[DiMargaret]

Reasons for high idle speed during cold start in summer: It is normal for a car to have high idle speed upon starting in summer, which then decreases after a while. This is a protective measure by the car for the engine, aimed at improving combustion efficiency and meeting emission standards. The extent of this phenomenon varies depending on the climate and temperature. The normal operating water temperature of an engine is around 90 degrees. In extremely low temperatures, after the engine starts, the water temperature sensor sends a signal to the ECU, prompting the engine to increase fuel injection and air intake, thereby raising the engine speed to quickly reach the normal operating temperature. As the engine temperature gradually rises, the idle speed will also gradually decrease to the normal state.