Patent ID: 7220214

Claim:
A shift control system for an automatic transmission for a vehicle, the automatic transmission including a frictional engaging element selectively engageable to establish a gear ratio, and a hydraulic pump to supply a hydraulic pressure to engage the frictional engaging element, the shift control system comprising: an oil temperature sensor to measure an oil temperature of hydraulic fluid flowing within the automatic transmission; a hydraulic controller to regulate the hydraulic pressure; and a control unit in operative communication with the oil temperature sensor and the hydraulic controller, to perform the following: determining a first oil temperature at a first time point when an engine of the vehicle is last stopped; determining a second oil temperature at a second time point when the engine is last restarted after the first time point; and controlling the hydraulic pressure to engage the frictional engaging element, in accordance with the first oil temperature and a temperature difference between the first oil temperature and the second oil temperature.