SPEED CHANGE CONTROLLER FOR AUTOMATIC TRANSMISSION

摘要

PURPOSE:To secure driving with good responsiveness against acceleration operation when a solenoid valve for speed change fails. CONSTITUTION:A valve 5 for speed change is controlled by a solenoid valve 2 for the speed change and a signal pressure from a valve 4 controlled by a solenoid valve 3 for engine brake. And such means are provided as a fail detection means 6 for detecting abnormality of the solenoid valve 2 for speed change, and a changeover setting means 7 for setting a specified speed change stage to the lower speed side from the maximum speed stage by controlling the solenoid valve 3 for the engine brake so as to drive the solenoid valve 2 for speed change by the engine brake signal pressure outputted of the solenoid valve 3 for the engine brake when any abnormality of the solenoid valve 2 for the speed change is detected.