Distribution of Hydraulic Pressure
As the engine turns, the automatic transmission fluid (ATF) pump starts to operate. ATF is drawn through the ATF filter and discharged into the hydraulic circuit. ATF flowing from the ATF pump becomes line pressure that is regulated by the regulator valve. Torque converter pressure, from the regulator valve, enters the torque converter through the lock-up shift valve and is discharged from the torque converter. The torque converter check valve prevents torque converter pressure from rising.
The powertrain control module (PCM) controls the shift solenoid valves ON and OFF. The shift solenoid valves control shift solenoid pressure to the shift valves. Applying shift solenoid pressure to the shift valves moves the position of the shift valve, and switches the port of hydraulic pressure. The PCM also controls the automatic transmission clutch pressure control (AT CPC) solenoid valves A and B.
The AT CPC solenoid valves A and B regulate the AT CPC solenoid pressure and apply the AT CPC solenoid pressure to CPC valves A and B. When shifting between upper gear and lower gear, the clutch is engaged by pressure from the CPC pressure mode.
The PCM controls one of the shift solenoid (SS) valves to move the position of the shift valve. This movement switches the port of the CPC and line pressure. Line pressure is then applied to the clutch, and the CPC pressure is intercepted.
When shifting is completed, the clutch is engaged with line pressure.
Port No. | Type of Pressure | Port No. | Type of Pressure | Port No. | Type of Pressure | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Line | 5N | CPC A or Line | 56 | LS A | ||||||||||||
2 | Line | 5D | CPC B or Line | 57 | LS B | ||||||||||||
3 | Line | 5G | CPC B or Line | 58 | LS C | ||||||||||||
3' | Reverse CPC or Line | 5K | CPC B or Line | 90 | Torque Converter | ||||||||||||
3" | Reverse CPC or Line | 6 | Modulate | 90' | Torque Converter | ||||||||||||
4 | Line | SA | SH A | 91 | Torque Converter | ||||||||||||
4' | Line | SB | SH B | 91' | Torque Converter | ||||||||||||
4" | Line | SC | SH C | 92 | Torque Converter | ||||||||||||
4A | CPC A | LA | LC A | 93 | ATF cooler | ||||||||||||
4B | CPC B | 9 | Line | 94 | Torque Converter | ||||||||||||
4C | CPC C | 10 | 1st Clutch | 95 | Lubrication | ||||||||||||
5B | CPC A | 15 | 1st Hold Clutch | 95' | Lubrication | ||||||||||||
5C | CPC B | 20 | 2nd Clutch | 96 | Torque Converter | ||||||||||||
5H | CPC B | 25 | Line | 97 | Torque Converter | ||||||||||||
5J | CPC B | 30 | 3rd Clutch | 99 | Suction | ||||||||||||
5A | CPC A or Line | 40 | 4th Clutch | X | Drain | ||||||||||||
5E | CPC A or Line | 50 | 5th Clutch | HX | High Position Drain | ||||||||||||
5F | CPC A or Line | 51 | 5th Clutch | hX | High Position drain | ||||||||||||
5M | CPC A or Line | 55 | CPC C or Line | AX | Air Drain | ||||||||||||
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R Position: Driving in Reverse Gear
The PCM turns shift solenoid (SS) valve C OFF. SS valve A stays OFF and SS valve B stays ON. SS valve C is turned OFF, and SH C pressure (SC) is applied to the right side of the reverse CPC valve. Then the reverse CPC valve moves to the left side, creating full line pressure. Line pressure to the 5th clutch is the same as when shifting to the R position, and 5th clutch pressure increases. The 5th clutch is engaged with line pressure.
Reverse Inhibitor Control
When R position is selected, while the vehicle is moving forward at speeds over 6 mph (10 km/h), the PCM outputs to turn the SS valves A and C ON, and SS valve B stays ON. The reverse CPC valve is moved to the right side and covers the port to stop the line pressure (3') to the servo valve. Line pressure (3') is not applied to the servo valve, and the 5th clutch pressure (50) is not applied to the 5th clutch, as a result, power is not transmitted to the reverse direction.
When used, ''left'' or ''right'' indicates direction on the hydraulic circuit.
Reverse
