| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately and reliably determine a gear error even in a low rotating speed range with a large read error in rotating speed detectors. <P>SOLUTION: A control system for an automatic transmission comprises a speed change mechanism for outputting rotation of an input shaft to an output shaft after a speed change, a plurality of engagement elements engaged and disengaged to establish each speed range of the speed change mechanism, a plurality of hydraulic servo devices for engaging and disengaging the engagement elements respectively by supplying and draining an output oil pressure corresponding to an electrical signal supplied to solenoid valves, and the input shaft rotating speed detector and output shaft rotating speed detector for detecting rotating speeds of the input shaft and output shaft respectively. For a command to establish a speed range, if a deviation between the ratio of the rotating speed of the input shaft detected by the input shaft rotating speed detector to the rotating speed of the output shaft detected by the output shaft rotating speed detector, and the gear ratio of another speed range remains within a given rate for a given time, a gear error is determined. <P>COPYRIGHT: (C)2003,JPO |
