Reverse Output Split Engine On

Reverse Output Split Engine On

When the transmission is operating in Reverse - Output Split (R), 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 main fluid pump provides hydraulic fluid pressure (refer to Engine Start Engine Start ). After Engine Start, the following changes would occur to the transmission's hydraulic and electrical systems.

1-3 Reverse Clutch Remains Applied

The 1-3 reverse clutch is applied for Engine Start, and remains applied for Reverse - Output Split (Engine ON).

Pressure Control (PC) Solenoid 4

The PC solenoid 4 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.

Shift Solenoid 2

The shift solenoid 2 is energized (ON) allowing actuator feed limit fluid to enter the solenoid 2 signal fluid circuit. Solenoid 2 signal fluid is routed through orifice #21 to the shift solenoid valve - mode A. Solenoid 2 signal fluid is also routed to the variable hi and 2-3-4 clutch regulator valve, and to the 1-3 reverse clutch regulator valve where it enters the PS1 fluid circuit.

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

Solenoid 2 signal fluid moves the shift solenoid valve - A, against spring force, to the applied position. 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 passes through the case and the transmission fluid pump cover into the 1-3 reverse clutch housing 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.

Torque Dampener Clutch Releases

Pressure Control (PC) Solenoid 5

The PC solenoid 5 is de-energized (OFF) allowing PCS 5 signal fluid to exhaust from the dampener bypass clutch valve.

Torque Dampener Clutch Assembly

Dampener clutch fluid exhausts from the torque dampener clutch assembly to the dampener bypass clutch valve allowing the torque dampener clutch to release.

Dampener Bypass Clutch Valve

Dampener bypass clutch valve spring force moves the dampener bypass clutch valve to the released position, allowing dampener clutch fluid pressure to exhaust through the valve into the exhaust backfill circuit.

Transmission Fluid Temperature (TFT) Sensor

Dampener clutch fluid pressure in the exhaust backfill circuit exhausts at the TFT sensor.

Variable Hi and 2-3-4 Clutch Remains Applied

Variable Hi and 2-3-4 Clutch Assembly

When the transmission is operating in Reverse - Output Split, and the engine is ON, the variable hi and 2-3-4 clutch remains applied. The routing of apply fluid to the variable hi and 2-3-4 clutch is similar to that described for Reverse - Output Split (Engine OFF), with the exception that VH 234 clutch/B cooling feed fluid passes through the applied shift solenoid valve - mode A into the VH 234 clutch feed circuit.

Shift Accumulation

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.

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.

Reverse Output Split Engine On