Line Pressure Control

LINE PRESSURE CONTROL




When torque signals corresponding to the engine drive power is sent from the ECM to the TCM, the TCM controls the line pressure solenoid. Using the line pressure solenoid pressure as a signal pressure, the pressure regulator valve is controlled, and the ATF discharged from the oil pump is regulated to an optimum level corresponding to the vehicle's running conditions.

1. LINE PRESSURE CONTROL IN NORMAL CONDITIONS




The line pressure which engages shift clutches to create 1st to 4th speeds, is regulated to a pressure required at each clutch according to the input torque.

2. LINE-PRESSURE CONTROL DURING ENGINE BRAKING IN SPORTS MODE




When engine braking is used to let the transmission downshift, the line pressure is regulated in accordance with the vehicle speed.

3. LINE-PRESSURE CONTROL DURING SHIFTING




During shifting, the line pressure is set to a level suitable for the input speed, input torque and the difference between the required and current gear speed.

4. LINE PRESSURE CONTROL WHEN ATF TEMPERATURE IS LOW




When the ATF temperature is low, the line pressure control characteristics is set higher than normal so that the clutches and brakes will operate at an earlier stage.