Park Or Neutral

Park Or Neutral - Engine Running:

PARK OR NEUTRAL (Engine Running)

When the vehicle is started, the oil pump generates fluid flow from the transmission sump through the filter into the pump. Filtered transmission fluid is directed to the pressure regulator valve.

- Pressure Regulator Valve: The pressure regulator valve regulates operating line pressure according to various driving conditions. Converter feed pressure is directed to the torque converter hydraulic system and regulated line pressure is directed to the [1][2]torque converter clutch regulated apply valve, actuator feed limit valve and manual valve.
- [1][2]Torque Converter Clutch Regulated Apply Valve (TCCRAV): Line pressure is supplied to the Torque Converter Clutch Regulator Apply Valve (TCCRAV) to be utilized in other gear ranges.
- Actuator Feed Limit Valve: Regulates actuator feed pressure to the 1-2,2-3, 3-4 shift valves the force motor and solenoids "A" and "B".
- Manual Valve: Line pressure from the pressure regulator valve is supplied to the manual valve to be utilized in other gear ranges. In Park range, line pressure is directed as PRND43, PRND4 and PRN fluid pressure.
- Pressure Switch Manifold (PSM): PRND4 and PRND43 fluid pressures from the manual valve are directed to their respective switches on the PSM, this sends a signal to the Powertrain Control Module (PCM) that the transmission is in Park range.
- Solenoid "A": Energized, signal "A" fluid pressure forces the 1-2 shift valve to the extreme left against spring force.
- Solenoid "B": De-energized, exhausting signal "B" fluid through the solenoid. Spring force holds the 2-3 shift valve to the extreme right.
- 1-2 Shift Valve: Held to the left against spring force by signal "A" fluid pressure.
- 2-3 Shift Valve: Held to the extreme right by spring force. This blocks the PRND4 fluid pressure at the 2-3 shift valve.
- 3-4 Shift Valve: Held to the extreme right by spring force and PRN fluid pressure.
- Front Servo: PRND43 fluid pressure from the manual valve is directed to the front servo which assists the spring force to hold the front servo off.