FAILURE MODE SHIFT PATTERN ALTERATION FOR AN ELECTRONICALLY CONTROLLED TRANSMISSION

摘要

An electronic transmission control in which the shift pattern is adjusted in the event of a sensed clutch or gear failure so that shifting between the nonfailed ratios is carried out in a manner which avoids engine stalling or overspeeding and significant stressing of the transmission gear elements. The original shift point lines involving the failed ratio are removed and replaced with a single shift point line positioned intermediate the original two. The new shift point line is determined in accordance with an arithmetic combination of the original shift point lines, and is limited based on engine overspeed and driveability considerations.