Abstract: An electronic engine control monitors engine speed, vehicle speed and determines various engine RPM values and RPM ranges used in fueling a molar vehicle engine to achieve desired engine speeds prior to and during an automatic gear shift sequence. The engine is coupled to a manual/automatic transmission that includes manually selectable gear operation modes and automatically selectable gear operation modes. In order to assist gear engagement of the automatically selectable gears, the engine is fueled to a series of predetermined RPM levels to rock the transmission gears into engagement. In so doing, throttle control by the operator is first inhibited and the engine is first governed to a synchronous RPM value. Throttle control is returned to the operator if gear engagement is verified within a first predetermined delay period.

Abstract: An electronic engine control controls the selection and confirmation of automatically selectable gears in a manual/automatic transmission. Failure to disengage the engine from the transmission within a predetermined time period, failure to reach a predetermined synchronous engine RPM window within another predetermined time period and failure to confirm gear engagement within yet another predetermined time period are three automatic shift failure modes which may cause an automatic shift attempt to fail or be aborted. A fourth automatic shift failure may occur if the clutch pedal is depressed during an automatic shift attempt. If any of the foregoing automatic shift failure mechanisms is detected, an error recovery algorithm which forms a part of the present invention determines the easiest/safest transmission gear to command to prevent the driver from having to manually attempt to engage the transmission after a failed automatic shift attempt.

Abstract: An electronic engine control monitors engine speed, vehicle speed and determines various engine RPM values and RPM ranges used in fueling a motor vehicle engine to achieve desired engine speeds prior to and during an automatic gear shift sequence. The engine is coupled to a manual/automatic transmission that includes manually selectable gear ratio operation modes and automatically selectable gear ratio operation modes. In order to verify engagement of the automatically selectable gear ratio operation modes, a predetermined reverse torque is introduced into the drivetrain by fueling the engine to certain predetermined levels after an automatic gear shift sequence begins and monitoring engine speed to test whether engine speed is within calculated synchronous engine speed ranges corresponding to the gear ratio of the desired automatically selectable gear ratio operation mode.

Abstract: A variable power drivetrain engine control system for a heavy duty vehicle such as a tractor/trailer combination or truck is disclosed. The engine control system provides higher output capability for the engine of the vehicle in accordance with certain detected conditions. If the vehicle speed falls a predetermined DELTA miles/hour below a LEARNED SPEED of the vehicle, the engine is enabled to operate at a higher power output capability until the vehicle resumes the LEARNED SPEED. Further, high output capability is enabled when the vehicle deceleration is in excess of a predetermined deceleration rate. Again, the high output capability is disabled once the vehicle retains the LEARNED SPEED velocity. The quantity DELTA can be variable with respect to actual vehicle speed to provide more responsive operation of the variable power drivetrain system thereby providing improved responsiveness to road conditions in accordance with relative vehicle speed.