Vehicle multiplex system with multifunction switches

Claim 1

In an automotive vehicle of the type comprising at least one power lock motor, at least one power window motor, at least one power lock switch, at least one power window switch, and an ignition circuit, the improvement comprising: a multiplex system comprising a central controller, at least one control bus coupled to the controller, means for applying multiplexed lock and window data signals to the at least one control bus indicative of the states of the power lock switch and the power window switch, respectively, means, coupled to the controller via the at least one control bus, for demultiplexing multiplexed lock and window control signals received from the controller via the control bus, and means for controlling activation of the power lock motor and the power window motor in response to the demultiplexed lock and control signals; means for applying a multiplexed ignition signal to the at least one control bus, wherein the multiplexed ignition signal is in a first, on state when the ignition circuit is switched on, and a second, off state when the ignition circuit is switched off; means for applying at least one multiplexed door status signal to the at least one control bus, wherein the multiplexed door status signal is in a first, closed state when a selected set of doors at the vehicle are all closed, and a second, open state when any of the doors in the selected set is open; means, included in the controller, for setting the multiplexed lock control signal in accordance with the lock data signal; means, included in the controller, for setting the multiplexed window control signal in accordance with the window data signal when the ignition signal is on and the door signal is closed; means, included in the controller, for preventing the window data signal from altering the state of the multiplexed window control signal when the ignition signal is off and the door signal is open.