Abstract: Electrical and mechanical operation of a bistable magnetically latching solenoid is diagnosed by monitoring induced voltage across the one of a pair of solenoid coils not energized. Energization of one of the pair of coils induces voltage across the other of the coils not energized and plunger actuation in response to energization induces another voltage therethrough. The various induced voltages are distinguishable as between those caused by energization of a coil or motion of the plunger.

Abstract: A gear shift lever and ignition lock cylinder are interlocked by a pair of independantly actuatable solenoids. Key removal from the ignition lock cylinder is prevented when the gear shift lever is not properly in a predetermined park position, and the gear shift lever, once properly in the predetermined park position, is inhibited from moving until the key removal is inhibited. Solenoid control is preferably by a programmable controller and logic.

Abstract: A battery discharge load current control system for a motor vehicle electrical system which can disconnect the battery from an electrical load to prevent over-discharge of the battery. The electrical load can be a so-called parasitic load which is of the type that is normally permanently connected to the battery. The electrical load is disconnected from the battery after the elapse of certain time periods. The system has a means for counting ignition cycles and after a certain count is attained, it is considered that the motor vehicle has been delivered to a purchasing customer. Prior to attaining the count, the time period is controlled to be about 1 or 2 days. After the count is attained, the time period is increased to be about 20 to 30 days.

Abstract: A system is described for automatically locking the doors of a vehicle equipped with electric power locks, wherein a first mode of operation is provided for vehicles having automatic transmissions and a second mode of operation is provided for vehicles having manual transmissions. The system includes means for sensing vehicle operating conditions necessary for locking vehicle doors in accordance with the two operating modes, and means for determining whether the vehicle has an automatic transmission. For vehicles having automatic transmissions, the system issues a door locking signal to lock the power door locks after an off-to-on transition of the vehicle ignition system is detected, when the automatic transmission is shifted from either the park or neutral range with the vehicle front doors closed.

Abstract: Apparatus for indicating fuel per pulse in a pulsed fuel injection system for an internal combustion engine, especially a diesel engine, includes a magnetic piston axially movable in a cylindrical bore in a fuel line to and from a stopped position blocking an inlet. The piston has an outer diameter just smaller than the inner diameter of the bore and is included in a magnetic circuit including an actuating coil having an inductance varying with piston position. Circuitry provides strong electrical current pulse to the coil prior to injection to move the piston to its stopped position and then provides a substantially weaker AC current to the coil while monitoring the voltage and rate of change of voltage thereacross. The rate of change of voltage indicates when piston movement in response to a fuel injection pulse ceases; and the voltage at that point indicates piston position and therefore fuel quantity injected.

Abstract: Passage of an engine piston through reference positions while traveling toward and away from a dead center position is sensed to produce pulses that define an engine displacement, the midpoint of which corresponds to the passage of the piston through the dead center position. Expressions of motion for the full displacement and one of the half displacements are simultaneously solved to determine the time at which the piston passed through the dead center position.

Abstract: A fuel limit controller includes a computer supplying a commanded absolute EGR control pressure that is a measure of fuel supplied per diesel engine revolution. An absolute EGR control pressure equal to the commanded absolute pressure is generated from a subatmospheric pressure source and atmospheric air so that the absolute EGR control pressure is limited to atmospheric pressure. Fuel per engine revolution is limited to the value represented by the absolute EGR control pressure so that the fuel limit is automatically compensated for altitude variations. The rate of change in the fuel limit in response to changes in the absolute EGR control pressure is limited to delay increases in fuel to match the time to purge excess exhaust gases from the engine intake manifold.

Abstract: A system for indicating the timing of an engine control event relative to the top dead center position of an internal combustion engine. A sensor responsive to piston movement develops pulses of equal angular width before and after the top dead center position of a selected piston, and the time relation of the sensor pulses with respect to the initiation of an engine control event is used to determine the timing of the engine control event with respect to the piston top dead center position. The timing so determined is compensated for engine acceleration by taking into account the difference in duration of the two sensor pulses.

Abstract: An exhaust gas recirculation control valve is positioned by a diaphragm responsive to the difference between a control pressure and atmospheric pressure. The control pressure is adjusted so that its absolute value is maintained equal to a command which varies with engine operating conditions, whereby exhaust gas recirculation is reduced automatically upon a decrease in atmospheric pressure.

Abstract: The position of a limit stop member which limits the mechanical position of a fuel metering valve in a diesel engine fuel injection pump is open loop controlled to a position offset from a desired fuel metering valve limit position by an amount in the increased fuel direction that is equal to the maximum possible error in the open loop controlled positional relationship between the limit stop and the fuel metering valve. The position of the fuel metering valve is sensed and compared with the maximum desired metering valve limit and when the fuel metering valve position exceeds the limit position, the position of the limit stop is closed loop adjusted to the maximum fuel metering valve position.

Abstract: An electrical connector arrangement for a motor vehicle steering assembly which includes a stationary steering column member rotatably supporting a steering shaft fixed with a steering wheel and characterized in that the steering column member supports a pair of concentric conductor rings that are adapted to be electrically connected to a sensor that forms a part of an occupant restraint cushion system. A heater element is provided for heating the conductor rings so as to prevent frost from forming thereon in cold weather and causing variations in the contact resistance of the electrical connector arrangement.

Abstract: In a direct current potential generating system of the type in which the system potential generating device field winding is energized by the generating system output potential connected in a field winding energizing circuit, an auxiliary direct current potential of a selected level is produced when the potential applied across the field winding decreases in magnitude to a preslected reduced level and is connected in the field winding energizing circuit in series aiding relationship with the generating system output potential.

Abstract: A glow plug or plugs for a Diesel engine is energized directly or indirectly through the normally closed contacts of a thermally operated switch, preferably a bimetal switch, in thermal communication with the engine and a local electric heater that is energized by the same source as the glow plug and controlled in unison with the glow plug. The bimetal switch is arranged to switch off at a temperature of the order of 80.degree. C. which, at an initial engine temperature of the order of -18.degree. C., permits the glow plug to heat to the order of 900.degree. C. The hysteresis in the bimetal switch is arranged to close the switch when the glow plug has cooled to the order of 810.degree. C., thus the glow plug is cycled between the order of 800.degree. C. and 900.degree. C. It has been found that the glow plug temperature rise at elevated temperatures is substantially less than proportional to heat input.