Abstract: A traction control system for a vehicle in which the rate of reduction of the torque input to the driven wheels of the vehicle in response to an excessive spin condition is varied as a function of the road surface coefficient of friction. The rate of increase of wheel spin is measured as an indicator of the road surface coefficient of friction and the area of the air intake of the engine is reduced at a rate that is in inverse proportion to the measured rate of increase of wheel spin. The rate of torque reduction is also made a function of the magnitude of wheel spin. The area of the air intake following recovery from an excessive spin condition is increased at a rate that is in inverse proportion to the road surface coefficient of friction.

Abstract: A method for recalibration of parametric relationships used in exhaust gas recirculation EGR control. When such recirculation would typically be inactive, relationships between parameters are measured, such relationships being normally measurable only with inactive EGR. New information from those measurements is combined with information from previous calibrations to provide update information necessary for subsequent EGR control.

Abstract: A dual slope drive-by-wire device circuit is used for controlling the position of the throttle of an engine. The circuit generates a command such that the response is a low gain for low values of throttle position for providing a desired resolution at low throttle angles such as idle, and a high gain for higher throttle angles, producing a desired range of throttle angle control. The throttle is positioned in response to the command signal.

Abstract: An engine control system monitors the force applied to the accelerator pedal and normal engine operating conditions during which the force applied to the pedal is normally zero and provides for normal engine operation if these conditions exist. When the force applied to the accelerator pedal is zero and none of the normal engine operating conditions at which the force applied to the accelerator pedal is normally zero exist, the engine is forced into a back-up control mode.

Abstract: This invention relates to a traction control system for a vehicle that combines the control of both air and fuel delivered to the vehicle engine for limiting the slip of the vehicle driven wheels.

Abstract: Acceleration enrichment for an internal combustion engine is provided in response to the rate of change of an unfiltered measurement of throttle position at the lower engine speeds and in response to the rate of change of a filtered measurement of throttle position at the higher engine speeds.

Abstract: A system for measuring the air flow into the engine over the full operating range thereof is described employing a pair of air flow measuring concepts selectively enabled dependent upon engine operation so as to accurately achieve a measurement of air flow over the full range of engine operation.

Abstract: A fuel supply passage has connections to two sources of fuel, and valves responsive to pressurization of the connections inhibit circulation of fuel from one of the sources to the other source.

Abstract: To measure the mass air flow in the induction passage of an engine, a small venturi located centrally in the passage serves as an air sampling tube. A slotted aperture in the wall of the tube at the venturi throat allows a hot film sensor to extend into the venturi throat from a support such as a printed circuit board mounted outside the venturi. The film sensor is in the form of a loop supported only at its ends on the support. The loop comprises a substrate of flexible insulating film material coated with an electrical resistance layer forming the active element of the sensor. The loop has a major dimension extending arcuately and transversely of the air flow through the venturi and a minor dimension extending parallel to the air flow.