An electronically controlled pneumatic brake system (2) for a vehicle 100, with a supply coupling head (24), a control coupling head (26), and an electronically controlled trailer control module (28) includes a first supply port (28.1), a trailer supply connection (28.2) for providing a trailer supply pressure (pT) to the supply coupling head (24), a trailer control connection (28.3) for providing a trailer control pressure (pB) to the control coupling head (26), an electro-pneumatic trailer control valve arrangement (40) for providing the trailer control pressure (pB), and a tractor protection valve electronic control unit (42). The electro-pneumatic trailer control valve arrangement (40) is configured to only supply a trailer control pressure (pB) to the trailer control connection (28.3) when compressed air is supplied to the trailer supply connection (28.2).