Selector mechanism for a motor vehicle transmission

A selector mechanism (5) for a motor vehicle transmission has a rotary switch (5a) rotatable in a housing to select an operating mode of the transmission (11). The rotary switch (5a) is connected to position sensors (9) for generating selector signals to a transmission control unit (10) which supplies control signals to an actuator (15) for operate the transmission according to the operating mode selected. The rotary switch (5a) is associated with a retractor actuator (16) controlled by the transmission control unit (10) in order to displace the selector between an inactive position in which it is retracted inside the housing and an active position in which it is projects outside the housing. The transmission control unit (10) sends a command to the retractor actuator device to move the rotary switch (5a) to the inactive position if a fault signal of the transmission has been detected. The transmission control unit (10) may also send a command to the retractor actuator to move the rotary switch to the inactive or active positions according to whether the engine is running.