Lockup control system for fluid coupling of automatic transmission

摘要

Lockup control system for engaging a lockup clutch to lock a fluid coupling to transmit engine output torque directly to an automatic transmission gear mechanism and disengaging the lockup clutch to unlock the fluid coupling to multiply engine output torque and transmit it to the automatic transmission gear mechanism causes a gear shift of the transmission gear mechanism to a gear in which engine brake is applied more effectively when a downhill slope is greater than a specified slope and controls the lockup clutch to relax in engagement when the gear shift is caused resulting from detection of a downhill slope greater than the specified slope.