The invention pertains to an electronic control module (3) for a motor vehicle electrical circuit (1), intended to be linked in a galvanically isolated manner to a motor vehicle electrical circuit (1) comprising at least one functional module (5) powered at high voltage, the control module comprising: —a connection bus (9), intended to be linked to an exterior interface (7), configured so as to conduct low-voltage electrical setpoint signals, emanating from the exterior interface (7) to the elements of the control module (3) to which they are addressed, —a microcontroller (1), configured to control the at least one functional module (5) as a function of the setpoint signals, characterized in that the microcontroller (11) and the connection bus (9) are linked by a non-galvanic coupler (13), provided with a low-voltage part (131) and with a high-voltage part (133), which are able to exchange at least one signal and are galvanically decoupled, and in that the control module furthermore comprises an electrical transformer (15), linked via outputs (153, 155, 157) to the high- and low-voltage parts (131, 133) of the non-galvanic coupler (13) and to the microcontroller (11) so as to provide their power supply, the transformer (15) being linked to a low-voltage source (17) via a breaker switch (19), and the connection bus (9) comprising a switching member (91) controlling the open or closed state of the breaker switch (19).