Hydraulic Operation

Line pressure hydraulic circuits:

• The position of the main regulator valve controls line pressure. The position of the main regulator valve is dependent on the pressure applied to it by the LPC solenoid through the VFS5 circuit.
• The main regulator valve varies pressure in the PUMP circuit by controlling hydraulic flow from the SCHG circuit into the pump suction circuit.
• Line pressure is supplied to the:
  • manual valve.
  • lubrication control valve.
  • converter release regulator valve.
  • bypass clutch control regulator valve.
  • solenoid pressure regulator valve.
  • D1 latch and regulator valves.
• In drive, the manual valve directs line pressure to the No. 1 shuttle valve and clutch A, C and E regulator valves.
• The No. 1 shuttle ball directs line pressure to the clutch B regulator valve.

Torque converter circuits:

• When the TCC is released, the converter release regulator valve applies pressure to the torque converter through the CREL circuit to release the TCC.
• CREL pressure exits the torque converter through the CAPLY circuit to the bypass clutch control regulator valve.
• The bypass clutch control regulator valve directs the pressure from the CAPLY circuit back to the converter release regulator valve through the CAPLY EX circuit.
• The converter release regulator valve directs the pressure from the CAPLY EX circuit to the drain back valve through the DBACK circuit.

Cooler and lubrication hydraulic circuits:

• The lubrication control valve directs line pressure to the transmission fluid cooler or the thermal bypass valve through the COOLF circuit.
• When the transmission fluid exits the transmission fluid cooler or thermal bypass valve, it provides lubrication to the transmission through the LUBE circuit. For information about transmission lubrication, refer to Mechanical Components and Functions  .

Solenoid hydraulic circuits:

• The solenoid pressure regulator valve supplies regulated line pressure to the shift, LPC and TCC solenoid through the SREG hydraulic circuit.
• The LPC solenoid applies varying pressure to the main regulator valve through the VFS5 hydraulic circuit. The LPC solenoid regulates line pressure by controlling the position of the main regulator valve.
• Below 5 kph (3 mph), SSD supplies pressure to the solenoid multiplex valve through the VFS4 circuit. Above 5 kph (3 mph), amperage to SSD is increased to decrease pressure to the solenoid multiplex valve and clutch D1 regulator valve to release the low/reverse clutch (D).
• The position of the solenoid multiplex valve allows pressure from the VFS4 circuit to be directed to the D1 latch and regulator valves through the CLDC circuit to position the valves for low/reverse clutch (D) application.
• SSA supplies pressure to the clutch A regulator and latch valves to position the valves for forward clutch (A) application.

Clutch hydraulic circuits:

• Line pressure is supplied by the pump to the D1 latch and regulator valves.
• Below 5 kph (3 mph), regulated line pressure from the D1 regulator valve is supplied to the low/reverse clutch (D) to apply the clutch. Above 5 kph (3 mph) the D1 regulator valve exhausts to release the low/reverse clutch and the Low/OWC continues to hold the rear planetary carrier with no engine braking.
• Regulated line pressure from the clutch A regulator valve is supplied to the forward clutch (A) to apply the clutch.

For hydraulic circuit information, refer to Hydraulic Circuits  .