Abstract: The signal provided by an oxygen sensor monitoring the exhaust discharge from an internal combustion engine having a closed loop air/fuel ratio controller is compensated so that the controller is insensitive to the difference between the rich-to-lean and lean-to-rich time responses of the sensor signal. The compensated sensor signal has fixed symmetrical voltage change slopes which are set at a value smaller than the smallest of the two slopes of the sensor signal when the compensated sensor signal being clamped at rich and lean voltages that are respectively less than and greater than the sensor rich and lean voltages.

Abstract: A closed loop fuel control system for an internal combustion engine is responsive to the output of a sensor monitoring the air/fuel ratio of the exhaust gases in the exhaust gas passage from the engine and therefore, after a transport time delay period dependent upon engine operating conditions, to the air/fuel ratio of the mixture supplied to the intake space of the engine and generates a first signal having a value preset to zero at each change in the sense of deviation of the sensed air/fuel ratio from a stoichiometric ratio and varying thereafter at a predetermined rate dependent upon the transport time delay and a second signal having a constant value for the period of the transport time delay after a change in the sense of deviation of the air/fuel ratio from a stoichiometric ratio and thereafter varying at the predetermined rate and in a sense determined by the sense of deviation of the air/fuel ratio from the predetermined ratio.

Abstract: A closed loop fuel controller for a vehicle internal combustion engine is responsive to the oxidizing/reducing conditions in the exhaust gases from the engine to provide a control signal for adjusting an air and fuel supply means and which varies in a sense tending to produce a predetermined air/fuel ratio. When the engine operation changes from one condition to another condition representing an acceleration or deceleration transient, the value of the air/fuel supply adjustment is preset to a value from a memory location addressed by the engine condition determined to produce the predetermined air/fuel ratio when the engine is accelerating and to a value from another memory location addressed by the engine condition determined to produce the predetermined air/fuel ratio when the engine is decelerating so that the air/fuel ratio adjustment is substantially instantaneously preset to the value determined to produce the predetermined ratio during engine accelerating and decelerating transient conditions.

Abstract: A closed loop air and fuel ratio controller is responsive to the oxidizing/reducing conditions in the exhaust gases from an internal combustion engine to provide a control signal having a value for adjusting both the idle and main fuel metering circuits of a carburetor so as to supply an air and fuel mixture to the engine at a predetermined ratio. Two memory elements are provided, each being associated with a respective one of the idle and main fuel metering circuit for storing a value of the control signal provided by the controller. During operation of each of the idle and main fuel metering circuits, the value of the control signal stored by the respective one of the storage elements is updated in accord with the average value of the control signal provided by the controller.

Abstract: A system displays messages one at a time to inform a vehicle operator of malfunctions or other events occurring in a vehicle with priority being given to the event of most importance whenever more than one event is sensed concurrently. A display device then selects messages for display and code switches are actuated to provide a unique electrical code signal for each message to indicate to the system which message is selected at a given moment. A number of sensors in the vehicle each respond to an event and an electrical sensor signal of unique value is provided for actuation of each sensor switch. A circuit compares the code signal with the sensor signal to drive the display device to select another message when the two signals are not in harmony and to display the selected message when the two signals are in harmony. A provision is made to render a sensor switch ineffective to affect the sensor signal when a sensor switch of higher priority is concurrently actuated.