Millenia L V6-2.5L DOHC (1997)
The 3-4 shift valve automatically shifts between third and fourth gear.
The 3-4 shift valve switches paths for line pressure applied to the 3-4 shift valve. The shift solenoid C ON-OFF signal is controlled by the transmission
control module.
With the shift solenoid C OFF, line pressure (17) becomes equal to line pressure (1), surpassing the combination of spring force and line pressure (7). As
a result, the valve is pushed to the left side and moves to third gear position.
With the valve in third gear, line pressure (1) joins line pressure (16), engaging the coasting clutch through the 2-3 shift valve. When vehicle speed
becomes high, the transmission control module turns ON the shift solenoid C, allowing line pressure (17) to be drained from the shift solenoid C.
Consequently, the combination of spring force and line pressure (7) push the valve to the right side, shifting to fourth. In gear position, (15) is drained,
releasing coasting clutch and engaging the 2-4 brake band.
Torque Converter Clutch Shift Valve