Drive Output Split Engine On
Drive Output Split Engine On
When the gear selector lever is moved to the Drive (D) position from the Neutral (N) position, and the HPCM determines that operating conditions are appropriate, the internal combustion engine (ICE) is started, the auxiliary fluid pump is turned OFF, and the TCM commands the following changes to the transmission's hydraulic and electrical systems in order to start the vehicle moving from a stopped position.
Variable Hi and 2-3-4 Clutch Applies
Pressure Control (PC) Solenoid 2 Trim
The PC solenoid 2 trim is energized (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.
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 VH 234 clutch feed fluid circuit and is routed to the shift solenoid valve - mode B.
Shift Solenoid Valve - Mode B
VH 234 clutch feed fluid passes through the shift solenoid valve - mode B 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.
1-3 Reverse Clutch Applies
Pressure Control (PC) Solenoid 4 Trim
The PC solenoid 4 trim is energized (ON) allowing actuator feed limit fluid to enter the PCS 4 signal circuit. PCS 4 signal fluid is then routed through orifice #18 to the 1-3 reverse clutch regulator valve.
1-3 Reverse Clutch Regulator Valve
PCS 4 signal fluid, at the 1-3 reverse clutch regulator valve, opposes 1-3 reverse clutch regulator valve spring force and 13 reverse clutch feedback fluid pressure to regulate line or auxiliary line pressure into the 13 reverse clutch/A cooling feed circuit.
#3 Ball Check Valve
13 reverse clutch feedback fluid unseats the #3 ball check valve, allowing excess pressure to pass into the actuator feed limit circuit. This helps to control clutch apply fluid pressure and clutch apply feel.
Shift Solenoid Valve - Mode A
13 reverse clutch/A cooling feed fluid passes through the shift solenoid valve - mode A and enters the 13 reverse clutch circuit.
1-3 Reverse Clutch Assembly
13 reverse clutch fluid enters the transmission fluid pump cover and moves the 1-3 reverse clutch piston against spring force to apply the 1-3 reverse clutch plates.
#1 Pressure Switch
Solenoid 2 signal fluid passes through the 1-3 reverse clutch regulator valve into the PS1 fluid passage. PS1 fluid opens the normally closed #1 pressure switch, signaling the TCM that the transmission is in Reverse Output Split.
Variable Hi and 2-3-4 Clutch Remains Applied
Variable Hi and 2-3-4 Clutch Assembly
With the exception of the switch to line fluid pressure from the main fluid pump assembly, no other changes occur to the transmission's hydraulic system and the variable hi and 2-3-4 clutch remains applied.
Shift Accumulation
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 apply of the variable hi and 2-3-4 clutch assembly.
1-3 Reverse Clutch Accumulator
13 reverse clutch fluid is also sent to the 1-3 reverse clutch accumulator assembly. 13 reverse clutch fluid moves the 1-3 reverse clutch accumulator piston against accumulator spring force to cushion the apply of the 1-3 reverse clutch assembly.
Drive Output Split Engine On
