Door for access to a transport vehicle, in particular of the train, tramway, metro, trolleybus or even bus type, this access door comprising: - a frame delimiting a bay, - an opening comprising at least one leaf (20, 25), each leaf being movable between an opening position of the bay, corresponding to free passage through this bay, as well as a closing position of this bay, the interior face of at least one leaf and/or the exterior face of at least one leaf, in particular both the interior face and the exterior face of a single leaf, being equipped with a detection member (3; 103; 203), the or each detection member comprising: -- a so-called mechanical detection element (32; 132; 232) capable of detecting pressing on the detection member, and -- a so-called contactless detection element (34; 134; 234) capable of detecting a presence in the vicinity of the detection member, this presence being accompanied or not by pressing on the detection member, - a control board (6; 106; 206), comprising a control unit (60; 160; 260) configured to control the movement of the or each leaf, - transfer means (4,5; 104,105; 204) which are capable of transferring first information (I; III; V), representative of the activation state of the mechanical element, as well as second information (II; IV; VI), representative of the activation state of the contactless element, from the detection member towards the control unit, each of said pieces of information having a so-called active value (I -VI) and a so-called inactive value (I - VI), said door being characterized in that the control board (6; 106; 206) further comprises a diagnostic unit (70; 170; 270) in the direction of which the first information (I; III; V) and the second information (II; IV; VI) are capable of being transferred from the detection member, said diagnostic unit being configured to identify a malfunction of at least the contactless detection element, when the first information has an active value (I; III; V) while the second information has an inactive value (II; IV; VI). - a frame delimiting a bay, - an opening comprising at least one leaf (20, 25), each leaf being movable between an opening position of the bay, corresponding to free passage through this bay, as well as a closing position of this bay, the interior face of at least one leaf and/or the exterior face of at least one leaf, in particular both the interior face and the exterior face of a single leaf, being equipped with a detection member (3; 103; 203), the or each detection member comprising: -- a so-called mechanical detection element (32; 132; 232) capable of detecting pressing on the detection member, and -- a so-called contactless detection element (34; 134; 234) capable of detecting a presence in the vicinity of the detection member, this presence being accompanied or not by pressing on the detection member, -- a so-called mechanical detection element (32; 132; 232) capable of detecting pressing on the detection member, and -- a so-called contactless detection element (34; 134; 234) capable of detecting a presence in the vicinity of the detection member, this presence being accompanied or not by pressing on the detection member, - a control board (6; 106; 206), comprising a control unit (60; 160; 260) configured to control the movement of the or each leaf, - transfer means (4,5; 104,105; 204) which are capable of transferring first information (I; III; V), representative of the activation state of the mechanical element, as well as second information (II; IV; VI), representative of the activation state of the contactless element, from the detection member towards the control unit, each of said pieces of information having a so-called active value (I -VI) and a so-called inactive value (I - VI), said door being characterized in that the control board (6; 106; 206) further comprises a diagnostic unit (70; 170; 270) in the direction of which the first information (I; III; V) and the second information (II; IV; VI) are capable of being transferred from the detection member, said diagnostic unit being configured to identify a malfunction of at least the contactless detection element, when the first information has an active value (I; III; V) while the second information has an inactive value (II; IV; VI).