The invention relates to an electrical plug connector, in particular to an electrical pin or socket connector, for a data transmission interface in the automotive field, having: a plug connector member (100) and a keyed mounting member (200) which can be mounted on the plug connector member (100) and which ensures correctly oriented insertion of an electrical counter plug connector on the electrical plug connector (1), the plug connector member (100) having a mounting projection (120) such that a wall (2) can be clamped between the mounting projection (120) and the keyed mounting member (200).