Reverse Series Mode Engine On

Reverse Series Mode Engine On

When the transmission is operating in Reverse - Series Mode (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 TCM commands the following changes to the transmission's hydraulic and electrical systems.

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 Low and 1-2 Reverse Clutch Remains Applied

Variable Low and 1-2 Reverse 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 low and 1-2 reverse clutch remains applied.

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.

Reverse Series Mode Engine On