Brake pressure regulator, pneumatic brake system and vehicle

The invention relates to a brake pressure regulator (110, 110a, 110b, 110c, 106), comprising:-a relay valve (202) for controlling the supply of pressurized air from a primary source (II) to at least one brake actuator (112a, 112b); -a first valve subunit (204) configured to be electronically actuated, where the first valve subunit (204) is configured to receive a primary supply pressure from the primary source (II), the primary supply pressure being intended to control the relay valve (202); and a second valve unit (206) configured to receive at least a secondary control pressure from a secondary source ("BST") and to receive at least a portion of the primary control pressure from the primary source (II) and to transfer either the primary control pressure or the secondary control pressure to the relay valve (202), wherein the primary control pressure from the primary source (II) is disconnected when the primary control pressure is transmitted to the relay valve (202), and/or the secondary control pressure fro