Electronic device for gear selection in an automatic transmission for motor vehicles with hall effect sensors and manual backup shaft

A motor vehicle transmission system for electronic control of gear selection comprising:

• an automatic transmission;
• a rotatable gear selection shaft operably connected to said automatic transmission;
• a stepping motor for rotatably driving said gear selection shaft to enable said shaft to selectively engage a plurality of transmission gears as a function of an angular position of said shaft;
• an electronic control unit electrically connected to said stepping motor and having a pair of electrical switches;
• an electronic device for controlling gear selection in said motor vehicle, said electronic device comprising a plurality of sensors cooperable with plural series of magnetic elements to enable said sensors to be selectively electrically connected to said control unit and said stepping motor in a manner which i) permits said control unit to determine said angular position of said gear selection shaft, and which ii) enables said stepping motor to vary said angular position of said selection shaft when said electrical switches of said control unit are actuated;
• and
• a manual gear actuator selectively cooperable with said gear selection shaft to provide a backup manual control of said transmission.