First Gear

Drive Range, First Gear

When the gear selector lever is moved to the Overdrive Range (D) position from the Neutral (N) position, after the first 1-2 shift has occurred, the following changes occure to shift the transmission into Overdrive Range - First Gear:

1-3 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 #36 to the 1-3 clutch regulator valve.

Shift Solenoid 1

The shift solenoid 1 is energized, allowing actuator feed limit fluid to enter the solenoid 1 signal fluid circuit. Solenoid 1 signal fluid is routed to the shift solenoid valve - mode A. Solenoid 1 signal fluid is also routed to the hybrid direct, 2-3-4 clutch regulator valve where it enters the PS2 fluid circuit, and to the 1-3 clutch regulator valve where it enters the PS4 circuit.

1-3 Clutch Regulator Valve

PCS 4 signal fluid, at the 1-3 clutch regulator valve, opposes 1-3 clutch regulator valve spring force and 13 clutch feedback fluid pressure to regulate line or auxiliary line pressure into the 13 clutch/A cooling feed circuit.

#2 Encapsulated Ball Check Valve

13 clutch feedback fluid unseats the #2 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 1 signal fluid is routed to the shift solenoid valve - mode A and moves the valve against shift solenoid valve - mode A spring force to the applied position. This allows 13 clutch/A cooling feed fluid to enter the 13 clutch circuit.

1-3 Clutch Assembly

13 clutch fluid enters the transmission case assembly and moves the 1-3 clutch piston against spring force to apply the 1-3 clutch plates.

#3 Pressure Switch

Solenoid 1 signal fluid passes through the hybrid direct, 2-3-4 clutch regulator valve into the PS3 fluid passage. PS3 fluid opens the normally closed #3 pressure switch, signaling the TCM that the transmission is in Drive Range - First Gear.

#4 Pressure Switch

Solenoid 1 signal fluid passes through the 1-3 clutch regulator valve into the PS4 fluid passage. PS4 fluid opens the normally closed #4 pressure switch, signaling the TCM that the transmission is in Drive Range - First Gear.

Drive Range - First Gear