Steuersystem eines automatischen Schaltgetriebes

摘要

PCT No. PCT/JP96/01590 Sec. 371 Date Feb. 13, 1997 Sec. 102(e) Date Feb. 13, 1997 PCT Filed Jun. 12, 1996 PCT Pub. No. WO97/00391 PCT Pub. Date Jan. 31, 1997An automatic transmission control system is equipped with a pressure modulating valve for regulating the engaging pressure to be supplied to frictional engagement elements for setting respective gear stages of the automatic transmission, a signal pressure output valve for providing signal pressure, and a switching valve. The control system further includes a switching valve for switching destinations of signal pressure for setting pressure regulation level between pressure modulating valve and other control valve; an abnormality-detection element for detecting, in gear shift to a gear stage set by the frictional engagement elements engaged on delivery of regulated oil pressure, abnormal regulation of engaging pressure to be delivered to the frictional engagement elements and abnormal operation due to delivery of the signal pressure to the control valve; and gear-shift-inhibition element for inhibiting shift to the gear stage in case that the abnormality-detection element detects at least one of abnormal pressure regulation and the abnormal operation.