SHIFT CONTROL DEVICE FOR AUTOMATIC TRANSMISSION

摘要

PURPOSE:To control learning very precisely and prevent erroneous learning by prohibiting learning control when the air-fuel ratio is lean in learning- controlling the oil pressure fed to or discharged from friction coupling devices in response to the output torque of a prime mover. CONSTITUTION:An engine control computer 20 decides the fuel injection quantity and ignition timing based on the signals inputted from a various-sensor group 50 and executes the feedback control of the air-fuel ratio. An automatic transmission control computer 70 controls an oil pressure control device 80 based on various input signals, controls the coupling states of friction coupling devices, and establishes a proper shift stage in response to the vehicle speed and accelerator opening. The output torque of an engine is detected, the target shift characteristic is determined from the detected output torque, and the oil pressure is learning-controlled so that the shift characteristic coincides with the target shift characteristic. When the lean state of the air-fuel ratio is detected, the learning control is prohibited.