Solenoid Control Valve

SOLENOID CONTROL VALVE
The transaxle control solenoids are electrohydraulic solenoid valves consisting of a housing, valve body, sliding armature and electromagnetic coil. They are a three port design with a pressure supply port, a pressure outlet or control pressure port, and an exhaust port.
The solenoids have normally open valves. When no voltage is applied to the terminals, a return spring holds the valve open and the solenoid will allow oil to flow from the supply port to the outlet pressure port. When current flows through the coil, the magnetic field is energized pulling the sliding armature against the return spring. When the armature is in this position, the valve is closed, the pressure supply port is blocked, and the control port is connected to the exhaust port.
The solenoids are located in the transaxle valve body. A solenoid may be completely energized (closed), de-energized (open), or Pulse Width Modulated (PWM).
When it is being modulated, the valve opens and closes up to 70 times per second. This allows a percentage of the oil pressure available at the supply port to pass to the control port. The actual percentage is determined by an electrically controlled duty cycle from the PCM. This is the ratio of the length of time the valve remains open (pulse width) to the total length of time of each cycle (one On and Off cycle).
The five actuators are the:
- Pressure Control Solenoid
- Torque Converter Clutch (TCC) Solenoid
- Shift Solenoid 2
- Shift Solenoid 3
- Shift Solenoid 4