Volvo V60 automatically rises at idle speed without stepping on the accelerator.

Sudden speed increase without stepping on the throttle may be caused by the throttle or the sensor near the throttle. When the owner steps on the accelerator pedal, the fuel injection quantity is not directly adjusted, but the throttle opening is adjusted. When the throttle opening becomes larger, the air entering the engine may also increase accordingly, and the ECU may also command the fuel injection system to increase the fuel injection quantity.

I think a car suddenly speeds up, which basically happens to every car. The high rotational speed when the car starts is called high idle speed, which is also idle speed, and is adjusted by the on-board computer. When the car starts under different conditions, the speed may also be obviously different. For example, in winter, the temperature difference between the starting state and the normal operation of the engine will be great, so the initial starting speed of the engine may also be increased accordingly.