An engine of a vehicle is provided with an engine control device including an idle speed control (ISC) device provided for an intake bypass passage connecting an upper side and a lower side of a throttle valve installed in an intake passage so as to control an idle speed of the engine by adjusting an amount of air flowing through the intake bypass passage at a time of idling of the engine. The engine control device includes a throttle opening degree sensor disposed in the intake passage and configured to detect a degree of opening of the throttle valve, an intake pressure sensor disposed in the intake passage and configured to detect an intake negative pressure at the lower side of the throttle valve, and a control unit configured to control an output of the engine. The control unit is configured to perform an engine output suppression control of suppressing the output of the engine after determining that an ISC valve of the ISC device is abnormal in a case where the degree of opening of the throttle valve detected by the throttle opening degree sensor is within a predetermined range and when the intake negative pressure detected by the intake pressure sensor is low compared with a threshold value.