| 摘要 |
PURPOSE:To prevent any trouble which would occur in automatic transmission, by maintaining an automatic transmission in a prescribed speed step at prescribed high line pressure when it is detected by an abnormal level detection circuit that one of an engine load signal, a vehicle speed signal and a pressure signal has an abnormal level. CONSTITUTION:Shift lever position signals 202-204, a vehicle speed signal 205 and an engine load signal 206 are applied to a speed step selection and judgement circuit 209 and an abnormal level detection circuit 1000. The detection circuit 1000 comprises an abnormal level detection circuit 1010 for a manual lever position signal, abnormal level detection circut 1020 for throttle opening degree signal (load signal), abnormal level detection circuit 1030 for vehicle speed signal and abnormal level detection circuit 1040 for line pressure signal. When an abnromality signal is generated by either of the circuits 1010, 1020, 1030, 1040, an abnormal level detection signal 1052a is produced by an OR circuit 1052. An automatic transmission is controlled through an abnormality processing circuit 1051 by the signal 1052a so that the transmission is maintained in a third speed step at high line pressure, for example. |
