Hydraulic Circuits
Line Pressure Hydraulic Circuits
| Item | Description |
|---|---|
| 1 | Mechanical pump |
| 2 | Pump output |
| 3 | Main regulator valve |
| 4 | Pump output decreased |
| 5 | LPC solenoid |
| 6 | LPC pressure |
| 7 | Isolator valve |
| 8 | Anti-backflow valve |
| 9 | Transmission fluid auxiliary pump |
| 10 | Line pressure |
| Sample External Link |
Insert my sample external link here.
The TCM controls line pressure with the LPC solenoid. Varying pressure from the LPC solenoid effects shift feel while allowing sufficient pressure for clutch application.
When the engine is running, the pump supplies pressure to the main regulator valve through the pump output circuit. Pressure from the LPC solenoid through the LPC pressure circuit controls the position of the main regulator valve.
The main regulator valve varies pressure in the pump output circuit.
The transmission fluid auxiliary pump, an electronic pump in turned on before an engine stop event to maintain line pressure, allowing the transmission to stay engaged during the stop event. This allows quick response on the engine restart because the transmission is already in gear.
Lubrication Hydraulic Circuits
| Item | Description |
|---|---|
| 1 | Fluid from torque converter |
| 2 | Lube control valve |
| 3 | Lube fluid circuit |
| 4 | Elevated exhaust pressure |
| 5 | Thermal bypass valve without active warm up |
| 6 | Bypass valve with active warm up |
| 7 | Fluid cooler |
A small amount of hot fluid from the torque converter is routed through a small orifice in the separator plate to the transmission fluid cooler or transmission fluid warmer/cooler. This fluid purges the cooler or warmer/cooler of air and keeps the cooler or warmer/cooler full of fluid when the vehicle is running.
On vehicles without active warm up, most of the hot fluid from the torque converter is routed to the thermal bypass valve. When TFT is below a specified temperature, the thermal bypass valve directs the fluid to the lube circuit. When TFT is above a specified temperature, the thermal bypass valve directs fluid to the transmission fluid cooler. Cold fluid from the transmission fluid cooler is routed to the lube circuit.
On vehicles with active warm up, most of the hot fluid from the torque converter is routed through the bypass valve to the transmission fluid warmer/cooler. Cold fluid from the transmission fluid cooler is routed to the lube circuit.
Fluid in the lube circuit enters the input shaft through the front support assembly and flows through passages in the input shaft and output shaft to provide lubrication for the transmission.