In a transmission hydraulic control system, a gain control valve may be used to switch between a low gain and a high gain based on line pressure. Line pressure may be controlled as a function of turbine torque. If the gain of a holding element or oncoming element changes during a shift as a result of changing turbine torque, shift quality may degrade. If the gain is set low at the beginning of the shift, the controller limits engine torque to ensure that the line pressure is not increased beyond a level that would cause a gain switch. If the gain is set high at the beginning of a shift, the controller maintains the line pressure high enough to prevent a switch to low gain, even if turbine torque drops.