1-2-3-4 Clutch Applies or Remains Applied

1-2-3-4 Pressure Control (PC) Solenoid 

The 1-2-3-4 PC solenoid defaults to its normally-high state (ON), allowing actuator feed limit fluid to enter the PCS 1-2-3-4 clutch fluid circuit. PCS 1-2-3-4 clutch fluid is routed through orifice #20 to the 1-2-3-4 clutch regulator valve, and through orifice #17 to the 1-2-3-4 clutch boost valve. If the transmission is operating in Fifth or Sixth gear when an electrical malfunction occurs, the 1-2-3-4 clutch will apply. If the transmission is operating in First, Second, Third or Fourth gear when the electrical malfunction occurs, the 1-2-3-4 clutch remains applied.

1-2-3-4 Clutch Boost Valve 

PCS 1-2-3-4 clutch fluid pressure acts on a differential area, moving the 1-2-3-4 clutch boost valve against 1-2-3-4 clutch boost valve spring force, to block 1-2-3-4 clutch fluid from entering the 1-2-3-4 clutch feedback circuit, and opening the 1-2-3-4 clutch feedback circuit to exhaust backfill. This results in the 1-2-3-4 clutch regulator valve moving to the full feed position, sending full 1-2-3-4 clutch feed pressure (full line pressure) to the 1-2-3-4 clutch.

1-2-3-4 Clutch Regulator Valve 

PCS 1-2-3-4 clutch fluid moves the 1-2-3-4 clutch regulator valve, against 1-2-3-4 clutch regulator valve spring force, to the applied position. This allows drive fluid pressure to pass through the valve into the 1-2-3-4 clutch fluid circuit. The 1-2-3-4 clutch fluid is then routed to the 1-2-3-4 clutch boost valve and through orifice #19 to the 1-2-3-4 clutch.

1-2-3-4 Clutch 

1-2-3-4 clutch fluid enters the transmission case assembly and moves the 1-2-3-4 clutch piston against spring force to apply the 1-2-3-4 clutch plates.

Accumulator 

PCS 1-2-3-4 clutch fluid is also routed to an accumulator valve. The accumulator valve is used to dampen any pressure irregularities occurring in the PCS 1-2-3-4 clutch fluid circuit. This helps to control clutch apply fluid pressure and clutch apply feel.