An apparatus for adjusting height of a motor vehicle have functions of detecting abnormality of sensors for detecting the vehicle height, driving a compressor independent of outputs of the sensors when pressure within a suspension is lower than a predetermined value, enabling actuation of the compressor after lapse of a predetermined time since turning-on of an ignition switch, enabling decreasing of the vehicle height for a predetermined time after turning-off of the ignition switch, and a self-diagnosing function for preventing runaway of the control.