An engine control device for a vehicle, comprising: - a control unit configured to be connected to the engine of a vehicle and to actuate the switching of the engine from a first idle rotation speed to a second idle rotation speed in which the number of engine revolutions is lower compared to the number of revolutions of the first idle speed; - a first sensor of the engine rotation speed, configured to be connected to the engine and to instantaneously sense and transmit to said control unit the number of revolutions completed by the engine in the unit of time; - a second sensor for detecting the presence of an operator at the controls of the vehicle, which second sensor is configured to transmit to the control unit a signal indicating the presence of an operator at the controls of the vehicle; - one or more additional sensors (S1,S2,...Sn), connected to the control unit, which are configured to transmit to the control unit additional signals indicating one or more additional operating parameters of the vehicle among: - traction clutch released; - position of non-actuation of the accelerator; - torque delivered by the engine lower than a given threshold; - temperature of the cooling liquid falling within a given range of values; - status of non-actuation of the power take-off of the vehicle, preferably checking the release of the power take-off clutch; - non-actuation position of the remote operating controls of the vehicle and/or of the tools associated with the vehicle; - battery voltage higher than a given value; - transmission oil temperature higher than a given value; - engine oil temperature higher than a given value; - non-actuation of the hydraulic hitch; characterized in that the control unit is configured to actuate a decrease in the engine rotation speed from the first idle speed toward the second idle speed instantaneously upon receiving: - a signal from the second sensor which indicates the operator's absence; - a signal from the first sensor which indicates that the engine is running at the first idle speed; and a positive signal from one or more of the further sensors (S1, S2,...Sn). - a control unit configured to be connected to the engine of a vehicle and to actuate the switching of the engine from a first idle rotation speed to a second idle rotation speed in which the number of engine revolutions is lower compared to the number of revolutions of the first idle speed; - a first sensor of the engine rotation speed, configured to be connected to the engine and to instantaneously sense and transmit to said control unit the number of revolutions completed by the engine in the unit of time; - a second sensor for detecting the presence of an operator at the controls of the vehicle, which second sensor is configured to transmit to the control unit a signal indicating the presence of an operator at the controls of the vehicle; - one or more additional sensors (S1,S2,...Sn), connected to the control unit, which are configured to transmit to the control unit additional signals indicating one or more additional operating parameters of the vehicle among: - traction clutch released; - position of non-actuation of the accelerator; - torque delivered by the engine lower than a given threshold; - temperature of the cooling liquid falling within a given range of values; - status of non-actuation of the power take-off of the vehicle, preferably checking the release of the power take-off clutch; - non-actuation position of the remote operating controls of the vehicle and/or of the tools associated with the vehicle; - battery voltage higher than a given value; - transmission oil temperature higher than a given value; - engine oil temperature higher than a given value; - non-actuation of the hydraulic hitch; - a signal from the second sensor which indicates the operator's absence; - a signal from the first sensor which indicates that the engine is running at the first idle speed;