LOCK-UP CONTROL DEVICE FOR AUTO-TRANSMISSION

摘要

A method and apparatus for use with an automotive vehicle having an automatic transmission operable with a working fluid. The automatic transmission is coupled to an engine through a torque converter operable in a lockup mode where a mechanical connection is completed between the engine and the automatic transmission in response to a lockup command signal. A degree to which the working fluid is degraded is detected while the torque converter is operating in response to the lockup command signal which is produced when the vehicle speed exceeds a reference value. When the detected degree exceeds a predetermined value, the reference vehicle speed value is increased.