Abstract: A pulse actuated clutch and control arrangement for coupling and decoupling a drive line of a vehicle relative to a wheel such as when shifting between two-wheel and four-wheel drive modes. The pulse actuated clutch has a coupling member that is permanently engaged with one of a driven member and a driving member. The coupling member is movable in a first direction to engage one of the driven and driving members and is movable in a second direction to engage both the driven and driving members. The coupling member is moved in the second direction by a first pulse of air pressure applied thereto. Formations of the piston assembly and the driven member cooperatively latch the piston in the second position to maintain the coupling member in engagement with both the driven and driving members following first pulse of air pressure. A second, greater magnitude pulse of air pressure moves the primary piston further to unlatch the piston and uncouple the driven member from the driving member.

Abstract: A plurality of sensors, such as a door handle lift switch, a headlight switch, and an ignition switch, are normally provided in an automotive electrical system. A master microcontroller normally is coupled to each of these sensors for receiving a signal therefrom and responsive thereto generating a corresponding controller signal. Power drivers, each operatively coupled to the master controller, normally are provided for energizing and powering loads coupled thereto, with each load being either an indicator or actuator that is operated responsive to its corresponding sensor. The self-diagnostic method includes the steps of mechanically actuating a selected one of the sensors, and then electrically actuating a first confirming indicator, such as an audible chime, indicative of the master controller receiving and successfully processing the corresponding sensing signal.

Abstract: Method and apparatus for monitoring the operation of a plurality of electrical loads in an automotive vehicle with a single current sensor. The current sensor detects the change in the total output current associated with the electrical loads and generates an output signal based on the current change. The apparatus also includes a controller which activates each electrical load at a given time to obtain a like plurality of timing signals so that each electrical load receives a portion of the output current. The controller processes the output signal and the timing signals to obtain a diagnostic signal related to an operating condition of at least one of the electrical loads. Finally, the controller controls an operating state of the at least one of the electrical loads based on the diagnostic signal.