Volt

Reverse Output Split Engine Off

When the gear selector lever is moved to the Reverse (R) position (from the Park position), and the internal combustion engine (ICE) is OFF, the following changes occur in the transmission's hydraulic and electrical systems.

Pressure Control (PC) Solenoid 2

The PC solenoid 2 is energised (ON) allowing actuator feed limit fluid to enter the PCS 2 signal circuit. PCS 2 signal fluid is then routed through orifice #20 to the variable hi and 2-3-4 clutch regulator valve.

Shift Solenoid 1

The shift solenoid 1 is energised (ON) allowing actuator feed limit fluid to enter the solenoid 1 signal fluid circuit. Solenoid 1 signal fluid is then routed through orifice #32 to the shift solenoid valve - mode B.

Variable Hi and 2-3-4 Clutch Regulator Valve

PCS 2 signal fluid, at the variable hi and 2-3-4 clutch regulator valve, opposes variable hi and 2-3-4 clutch regulator valve spring force and VH 234 clutch feedback fluid pressure to regulate line or auxiliary line pressure into the VH 234 clutch/B cooling feed circuit.

Variable Hi and 2-3-4 Clutch Boost Valve

PCS 2 signal fluid pressure acts on a differential area of the variable hi and 2-3-4 clutch boost valve, moving the valve against variable hi and 2-3-4 clutch boost valve spring force to regulate VH 234 clutch/B cooling feed fluid into the VH 234 clutch feedback circuit. As PCS 2 signal fluid pressure is increased to a given value, the variable hi and 2-3-4 clutch boost valve opens the VH 234 clutch feedback circuit to exhaust. This results in the variable hi and 2-3-4 clutch regulator valve moving to the full feed position, sending full VH 234 clutch feed pressure (full line pressure) to the variable hi and 2-3-4 clutch.

Shift Solenoid Valve - Mode A

VH 234 clutch/B cooling feed fluid passes through the shift solenoid valve - mode A into the B cooling supply circuit and is routed to the shift solenoid valve - mode B.

Shift Solenoid Valve - Mode B

Solenoid 1 signal fluid moves the shift solenoid valve - B, against spring force, to the applied position. VH 234 clutch/B cooling feed fluid passes through the valve into the VH 234 clutch circuit and is routed to the variable hi and 2-3-4 clutch assembly.

Variable Hi and 2-3-4 Clutch Assembly

VH 234 clutch fluid is directed to the variable hi and 2-3-4 clutch piston to apply the variable hi and 2-3-4 clutch plates and achieve Reverse - Output Split.

Variable Hi and 2-3-4 Clutch Accumulator

VH 234 clutch fluid is also sent to the variable hi and 2-3-4 clutch accumulator assembly. VH 234 clutch fluid moves the variable hi and 2-3-4 clutch accumulator piston against accumulator spring force to cushion the application of the variable hi and 2-3-4 clutch assembly.