A valve device for controlling a pneumatic trailer air suspension system, the valve device comprising: at least one cushion connection (2, 4) connectable to a pneumatic spring cushion (102a, 102b, 102c, 104a, 104b, 104c) of the air suspension system, a supply connection connectable to a compressed air reservoir, and a venting connection connectable to the atmosphere, wherein the valve device has a pneumatically actuable main valve unit, an electrical pilot control unit, and a manual pilot control unit, the electrical pilot control unit and manual pilot control unit are adapted for providing at least one first pilot pressure to said main valve unit, wherein said main valve unit is adapted to provide at least a cushion pressure (pC) at said cushion connection (2, 4) dependent on the first pilot pressure, wherein the manual pilot control unit comprises a manually operatable camshaft for controlling at least a first valve body, wherein said camshaft at least is rotatable into a driving position, a lowering position and a lifting position, wherein the valve device has a shaft sensor for directly determining the rotational position of said camshaft, wherein the valve device comprises an electronic control unit connected to said shaft sensor and said electrical pilot control unit, wherein the electronic control unit comprises means for receiving a sensor signal (SR1, SR2, SR3) from said shaft sensor indicative for one of the positions (R1, R2, R3), wherein the electronic control unit comprises means for providing at least a first switching signal corresponding to the sensor signal (SR1, SR2, SR3) to said electrical pilot control unit, characterized in that said camshaft comprises a sensor portion, said sensor portion comprising a sensible structure, and wherein said sensible structure comprises at least a first, a second, and a third surface (26a, 26b, 26c), which are formed at different minimum distances to the shaft sensor and the shaft sensor is adapted to measure a distance to said first, second, and third surfaces (26a, 26b, 26c). at least one cushion connection (2, 4) connectable to a pneumatic spring cushion (102a, 102b, 102c, 104a, 104b, 104c) of the air suspension system, a supply connection connectable to a compressed air reservoir, and a venting connection connectable to the atmosphere, wherein the valve device has a pneumatically actuable main valve unit, an electrical pilot control unit, and a manual pilot control unit, the electrical pilot control unit and manual pilot control unit are adapted for providing at least one first pilot pressure to said main valve unit, wherein said main valve unit is adapted to provide at least a cushion pressure (pC) at said cushion connection (2, 4) dependent on the first pilot pressure, wherein the manual pilot control unit comprises a manually operatable camshaft for controlling at least a first valve body, wherein said camshaft at least is rotatable into a driving position, a lowering position and a lifting position, wherein the valve device has a shaft sensor for directly determining the rotational position of said camshaft, wherein the valve device comprises an electronic control unit connected to said shaft sensor and said electrical pilot control unit, wherein the electronic control unit comprises means for receiving a sensor signal (SR1, SR2, SR3) from said shaft sensor indicative for one of the positions (R1, R2, R3), wherein the electronic control unit comprises means for providing at least a first switching signal corresponding to the sensor signal (SR1, SR2, SR3) to said electrical pilot control unit, characterized in that said camshaft comprises a sensor portion, said sensor portion comprising a sensible structure, and wherein said sensible structure comprises at least a first, a second, and a third surface (26a, 26b, 26c), which are formed at different minimum distances to the shaft sensor and the shaft sensor is adapted to measure a distance to said first, second, and third surfaces (26a, 26b, 26c).