Control system for automatic transmission

A control system for an automatic transmission having a plurality of gear stages, which is capable of generating a torque down signal for reducing an output torque of an engine connected to the automatic transmission when a one-way clutch for setting a given gear stage is changed from disengaged state to engaged state in non-shift condition of the automatic transmission, comprising:

• a release detecting means for detecting disengagement of said one-way clutch;
• a power-on detecting means for detecting change in an operation of said engine from driven mode to drive mode;
• a throttle opening detecting means for detecting a throttle opening of said engine;
• a throttle opening estimating means for estimating a second throttle opening when a first predetermined time has elapsed from the time at which the operation of the engine is changed from driven mode to drive mode with the one-way clutch disengaged, on the basis of a first throttle opening detected when the operation of the engine is changed from driven mode to drive mode;
• and
• a torque down instructing means for generating a torque down signal for reducing the output torque of the engine, either in case said second throttle opening estimated by said throttle opening estimating means is not less than a first predetermined reference value, or in case a third throttle opening when a second predetermined time has elapsed from the time at which the operation of engine is changed from driven mode to drive mode with the one-way clutch disengaged, is not less than a second predetermined reference value.