Volt

Drive Series Mode Engine Off

When the gear selector lever is moved to the Drive (D) position from the Neutral (N) position, and the internal combustion engine (ICE) is OFF, the following changes occur in the transmission's hydraulic and electrical systems in order to start the vehicle moving from a stopped position.

Pressure Control (PC) Solenoid 3

The PC solenoid 3 is energised (ON) allowing actuator feed limit fluid to enter the PCS 3 signal circuit. PCS 3 signal fluid is then routed through orifice #30 to the variable low and 1-2 reverse clutch regulator valve; through orifice #12 to the variable low and 1-2 reverse clutch boost valve; and to the shift solenoid valve - mode B.

Variable Low and 1-2 Reverse Clutch Regulator Valve

PCS 3 signal fluid, at the variable low and 1-2 reverse clutch regulator valve, opposes variable low and 1-2 reverse clutch regulator valve spring force and VL 12 reverse clutch feedback fluid pressure to regulate line or auxiliary line pressure into the VL 12 reverse clutch feed circuit.

Variable Low and 1-2 Reverse Clutch Boost Valve

PCS 3 signal fluid pressure acts on a differential area of the variable low and 1-2 reverse clutch boost valve, moving the valve against variable low and 1-2 reverse clutch boost valve spring force to regulate VL 12 reverse clutch feed fluid into the VL 12 reverse clutch feedback circuit. As PCS 3 signal fluid pressure is increased to a given value, the variable low and 1-2 reverse clutch boost valve opens the VL 1-2 reverse clutch feedback circuit to exhaust. This results in the variable low and 1-2 reverse clutch regulator valve moving to the full feed position, sending full VL 12 reverse clutch feed pressure (full line pressure) to the variable low and 1-2 reverse clutch.

Shift Solenoid Valve - Mode B

VL 12 reverse clutch feed fluid is routed to the shift solenoid valve - mode B, where it passes through the valve into the VL 12 reverse clutch circuit.

Variable Low and 1-2 Reverse Clutch Assembly

VL 12 reverse clutch fluid pressure enters the case assembly behind the variable low and 1-2 reverse clutch piston and moves the piston against spring force to apply the variable low and 1-2 reverse clutch plates.

Variable Low and 1-2 Reverse Clutch Accumulator

VL 12 reverse clutch fluid is also sent to the variable low and 1-2 reverse clutch accumulator assembly. VL 12 reverse clutch fluid moves the variable low and 1-2 reverse clutch accumulator piston against accumulator spring force to cushion the apply of the variable low and 1-2 reverse clutch assembly.