A device for dosing inlet fluid in an engine and for regulating the temperature thereof is disclosed. The device has a dosing body on which a first and a second circulation channel are arranged. First and second movable flow dosage flaps are arranged in the circulation channels. The dosing body also includes an actuator motor and a kinematic capable of actuating the first and/or the second flap. The device additionally includes first and second tubes, at least one of the tubes having a means for modifying the temperature of the fluid. The kinematic is shaped so as to position at rest, if flap actuation is lost, the first flap of the cool channel being then in a fully open position and the second flap of the hot channel being then in a fully closed position.