Patent ID: 7584681
Filing Date: 2009-09-08
Classification: F16H,Y10T

Abstract:
1. An automatic transmission control system comprising: a lever position sensor designed to produce signals each of which represents one of a parking position, a reverse position, a neutral position, and a drive position to which a gear shift lever is shifted manually by an operator; a plurality of hydraulic control valves working to control hydraulic pressures to be supplied to frictional elements of an automatic transmission; a manual selector valve which selectively establishes hydraulic supply circuits leading to said hydraulic control valves following a shifting motion of the gear shift lever, said manual selector valve working to establish predetermined ones of the hydraulic supply circuit to achieve a selected one of forward gears of the automatic transmission only when the gear shift lever is placed in the drive position; and a gear change controller which monitors a position of the gear shift lever using the signal produced by said lever position sensor and operates said hydraulic control valves to hydraulically control engagement of the frictional elements of the automatic transmission to establish a selected one of gears of the automatic transmission, when the signal from said lever position sensor represents the position of the gear shift lever other than the drive position, and a predetermined condition is encountered, said gear change controller deeming the gear shift lever to be placed in the drive position and performing a deemed D-position hydraulic transmission control to establish a given one of the forward gears of the automatic transmission.