System for determining an equivalent throttle valve for controlling automatic transmission shift points

Abstract

A system is disclosed for determining an effective throttle value of an internal combustion engine for controlling automatic transmission shift points. In one embodiment, the system is operable to determine an effective throttle value as a function of commanded fueling and engine speed under operating conditions wherein engine torque is requested by a system/component other than manual throttle control to thereby provide a throttle value indicative of what throttle position or percentage would be under present operating conditions if engine torque was being requested via manual throttle control. The present invention accordingly overcomes deficiencies in known automatic transmission shift point control systems by continuously computing an equivalent throttle percentage whenever fueling or requested torque values are not dominated by actual throttle (e.g. accelerator pedal) percentage. The equivalent throttle parameter value is approximately what the throttle percentage would be if manual throttle percentage was the dominant source of requested torque. Transmission shift point logic may resultantly be simplified by basing transmission shift points on the equivalent throttle parameter during non-manual fueling control just as transmission shift points are based on throttle percentage during manual fueling conditions.