Abstract: The invention relates to a throttle valve device including a housing (4; 54; 54'; 98), a throttle valve spindle (3; 53; 53'; 99) on which a throttle valve (2; 52; 52'; 100) movable in the housing (4; 54; 54'; 98) between a first air passage chamber (62; 62'; 92) and a second such chamber (63; 63'; 103) leading to the vehicle engine is held in at least one closed position (DS), an idling position (MS) and a full-throttle position (VS) and a control unit (11; 61; 61'; 107) having at least one control motor unit (5; 55; 55'; 91) and connected to the throttle valve spindle (3; 53; 53'; 99). The second air passage chamber (63; 63'; 103) is connected to a back-up air control device (2, 3, 8, 9, 10, LHP1; 52, 55, 58, LHP2; 52', 55', 58', LHP3; 95, 102) by which enough air can be fed to the engine in the event of the breakdown of the control motor unit (5; 55; 55'; 91) to allow the vehicle movement.