Automatic Transmission/Transaxle

HYDRAULIC CONTROL SYSTEM





DESCRIPTION
^ Better and smoother shift quality
^ In order to prevent ATF leakage from the valve body or each elements, the exhaust ports have been grouped into only one with an addition of a check ball.
^ If a failure occurs in its electric control, the switch valve and fail safe valve is able to move to enable 3rd speed drive or reverse.
^ The hydraulic system consists of oil pump, regulator valve, solenoid valves, pressure control valve and valve body.

OPERATION COMPONENTS AND FUNCTIONS
Oil Pump
The oil pump is made of aluminum to reduce its weight. The oil pump is not a serviceable part; it must be replaced as a pump assembly.
Do not disassemble the pump as improper alignment during assembly will cause pump failure and could cause damage to the transaxle.
When removing the oil pump from the T/M case, the S.S.T. (09452-33100) must be used.

OPERATION OF EACH VALVE
Torque converter pressure control valve: The function of this valve is to maintain a constant pressure within the torque converter.
Damper clutch control valve: Its function is to control the hydraulic pressure that acts on the Damper Clutch. Manual valve :The position of the manual valve is determined by the selector lever and applies or cuts line pressure to different valves.
Pressure control valve & Solenoid valve: The pressure control valve prevents a rapid decrease in hydraulic pressure when the clutch becomes disengaged. It also reduces the sharp increase in input shaft speed during clutch to clutch control.
Switch valve: When the OD clutch is applied, the hydraulic pressure is applied to the regulator valve via the switch valve. Hence, the line pressure is reduced at 3rd and 4th gear.
Fail Safe Valve-A: During fail safe mode, this valve releases the pressure in the LR Brake.
Fail Safe Valve-B: During fail safe mode, this valve cuts the pressure from the 2nd pressure control valve to 2nd brake.

HYDRAULIC FLOW
P AND N POSITION





The TCM (PCM) controls the solenoid valves. The conditions of the solenoid valve and positions of the solenoid valve are as follows :
^ The LR solenoid valve is turned off, and the LR pressure solenoid valve is moved to the left side.
^ The 2nd solenoid valve is turned on, and the 2nd pressure solenoid valve remains in the right side.
^ The UD solenoid valve is turned on, and the UD pressure solenoid valve remains in the right side.
^ The OD solenoid valve is turned on, and the OD pressure solenoid valve remains in the right side.
^ The line pressure is supplied to the regulator valve and the fail-safe valve A.
^ The line pressure is supplied to each element (fail-safe valve B, switch valve, DCCV, LR solenoid valve, LR pressure control valve).
^ The fail-safe valve B moves to the left side by the line pressure through the manual valve.
^ The switch valve moves to the left side by the line pressure.
^ The line pressure is supplied to the DCCV, and DCCV moves to the right side.
^ The line pressure is supplied to the LR pressure control valve and the LR solenoid valve, and TCM (PCM) turns off the LR solenoid valve, so the line pressure is supplied to the LR brake through the switch valve and the fail-safe valve A.
^ The regulator valve moves to the left side by the line pressure through the manual valve, and the line pressure is supplied to the torque converter pressure control valve and the oil pump.

D POSITION: 1ST GEAR





The TCM (PCM) controls the solenoid valves. The conditions of the solenoid valve and positions of the solenoid valve are as follows :
^ The LR solenoid valve is turned off, and the LR pressure solenoid valve is moved to the left side.
^ The 2nd solenoid valve is turned on, and the 2nd pressure solenoid valve remains in the right side.
^ The UD solenoid valve is turned off, and the UD pressure solenoid valve is moved to the left side.
^ The OD solenoid valve is turned on, and the OD pressure solenoid valve remains in the right side.
^ The line pressure is supplied to the regulator valve and the fail-safe valve A.
^ The line pressure is supplied to each element (fail-safe valve B, switch valve, damper clutch control valve, LR solenoid valve, LR pressure control valve). The line pressure through the manual valve is supplied to each element (DCCV, 2nd solenoid valve, 2nd pressure control valve, OD solenoid valve, OD pressure control valve, UD solenoid valve, UD pressure control valve).
^ The fail-safe valve B moves to the left side by the line pressure.
^ The switch valve moves to the left side by the line pressure.
^ The line pressure is supplied to the DCCV, and TCM (PCM) turns off the DCCSV, so the DCCV remains in the right side
^ The line pressure is supplied to the LR pressure control valve and the LR solenoid valve, and TCM (PCM) turns off the LR solenoid valve, so the line pressure is supplied to the LR brake through the switch valve and the fail-safe valve A.
^ The line pressure is supplied to the UD pressure control valve and the UD solenoid valve, and TCM (PCM) turns off the UD solenoid valve, so the line pressure is supplied to the UD clutch and the fail-safe valve B.
^ The regulator valve moves to the left side by the line pressure through the manual valve, and the line pressure is supplied to the torque converter pressure control valve and the oil pump.

D POSITION: 2ND GEAR





The TCM (PCM) controls the solenoid valves. The conditions of the solenoid valve and positions of the solenoid valve are as follows :
^ The LR solenoid valve is turned on, and the LR pressure solenoid valve remains in the right side.
^ The 2nd solenoid valve is turned off, and the 2nd pressure solenoid valve is moved to the left side.
^ The UD solenoid valve is turned off, and the UD pressure solenoid valve is moved to the left side.
^ The OD solenoid valve is turned on, and the OD pressure solenoid valve remains in the right side.
^ The line pressure is supplied to the regulator valve and the fail-safe valve A.
^ The line pressure is supplied to each element (fail-safe valve B, switch valve, damper clutch control valve, LR solenoid valve, LR pressure control valve). The line pressure through the manual valve is supplied to each element (DCCV, 2nd solenoid valve, 2nd pressure control valve, OD solenoid valve, OD pressure control valve, UD solenoid valve, UD pressure control valve).
^ The fail-safe valve B moves to the right side by the line pressure through 2nd pressure control valve and the line pressure through the UD pressure control valve. The pressure through the manual valve is supplied to the fail-safe valve A, and the fail-safe valve A moves to the left side
^ The switch valve moves to the left side by the line pressure.
^ The line pressure is supplied to the DCCV and the DCCSV, and TCM (PCM) turns off the DCCSV, so the DCCV remains in the right side
^ The line pressure is supplied to the 2nd pressure control valve and the 2nd solenoid valve, and TCM (PCM) turns off the 2nd solenoid valve, so the line pressure is supplied to the 2nd brake and the fail-safe valve A through the fail-safe valve B.
^ The line pressure is supplied to the UD pressure control valve and the UD solenoid valve, and TCM (PCM) turns off the UD solenoid valve, so the line pressure is supplied to the UD clutch and the fail-safe valve B.
^ The regulator valve moves to the left side by the line pressure through the manual valve, and the line pressure is supplied to the torque converter pressure control valve and the oil pump.

D POSITION: 3RD GEAR





The TCM (PCM) controls the solenoid valves. The conditions of the solenoid valve and positions of the solenoid valve are as follows :
^ The LR solenoid valve is turned on, and the LR pressure solenoid valve remains in the right side.
^ The 2nd solenoid valve is turned on, and the 2nd pressure solenoid valve remains in the right side.
^ The UD solenoid valve is turned off, and the LID pressure solenoid valve is moved to the left side.
^ The OD solenoid valve is turned off, and the OD pressure solenoid valve is moved to the left side.
^ The line pressure is supplied to the regulator valve and the fail-safe valve A.
^ The line pressure is supplied to each element (fail-safe valve B, switch valve, DCCV, LR solenoid valve, LR pressure control valve).
^ The line pressure through the manual valve is supplied to each element (DCCSV, 2nd solenoid valve, 2nd pressure control valve, OD solenoid valve, OD pressure control valve, UD solenoid valve, UD pressure control valve).
^ The fail-safe valve B moves to the right side by the line pressure through the UD pressure control valve and the line pressure through the OD pressure control valve.
^ The pressure is supplied to the fail-safe valve A through the OD pressure control valve, but the fail-safe valve A does not move to the right side
^ The line pressure is supplied to the DCCV and the DCCSV, and TCM (PCM) turns on the DCCSV, and the DCCV moves to the left side, and the damper clutch is operated.
^ The line pressure is supplied to the UD pressure control valve and the LID solenoid valve, and TCM (PCM) turns off the UD solenoid valve, so the line pressure is supplied to the UD clutch and the fail-safe valve B.
^ The line pressure is supplied to the OD pressure control valve and the OD solenoid valve, and TCM (PCM) turns off the OD solenoid valve, so the line pressure is supplied to the OD clutch and the fail-safe valve A/B and the switch valve.
^The switch valve moves to the right side by the line pressure through the OD pressure control valve.
^ The regulator valve moves to the left side by the pressure through the manual valve and the pressure through the switch valve.

D POSITION: 4TH GEAR





The TCM (PCM) controls the solenoid valves. The conditions of the solenoid valve and positions of the solenoid valve are as follows :
^ The LR solenoid valve is turned on, and the LR pressure solenoid valve remains in the right side.
^ The 2nd solenoid valve is turned off, and the 2nd pressure solenoid valve is moved to the left side.
^ The UD solenoid valve is turned on, and the UD pressure solenoid valve remains in the right side.
^ The OD solenoid valve is turned off, and the OD pressure solenoid valve is moved to the left side.
^ The line pressure through the manual valve is supplied to the regulator valve and the fail-safe valve A.
^ The line pressure is supplied to each element (fail-safe valve B, switch valve, DCCV, LR solenoid valve, LR pressure control valve).
^ The line pressure through the manual valve is supplied to each element (DCCSV, 2nd solenoid valve, 2nd pressure control valve, OD solenoid valve, OD pressure control valve, UD solenoid valve, UD pressure control valve).
^ The fail-safe valve B moves to the right side by the line pressure through the 2nd pressure control valve and the line pressure through the OD pressure control valve.
^ The line pressure through the OD pressure control valve is supplied to the fail-safe valve A, and the fail-safe valve A moves to the right side by the line pressure through the fail-safe valve B and the line pressure through the OD pressure control valve.
^ The line pressure is supplied to the DCCV and the DCCSV, and TCM (PCM) turns on the DCCSV, so DCCV moves to the right side, and the damper clutch is operated.
^ The line pressure is supplied to the OD pressure control valve and the OD solenoid valve, and TCM (PCM) turns off the OD solenoid valve, so the line pressure is supplied to the OD clutch and the fail-safe valve A/B and the switch valve.
^ The line pressure is supplied to the 2nd pressure control valve and the 2nd solenoid valve, and TCM (PCM) turns off the 2nd solenoid valve, so the line pressure through the 2nd pressure control valve is supplied to the 2nd brake through the fail-safe valve B.
^ The regulator valve moves to the left side by the line pressure through the manual valve and the line pressure through the switch valve.

REVERSE POSITION





The TCM (PCM) controls the solenoid valves. The conditions of the solenoid valve and positions of the solenoid valve are as follows :
^ The LR solenoid valve is turned off, and the LR pressure solenoid valve is moved to the left side.
^ The 2nd solenoid valve is turned on, and the 2nd pressure solenoid valve remains in the right side.
^ The UD solenoid valve is turned on, and the UD pressure solenoid valve remains in the right side.
^ The OD solenoid valve is turned on, and the OD pressure solenoid valve remains in the right side.
^ The line pressure through the manual valve is supplied to the reverse clutch and the fail-safe valve B.
^ The line pressure is supplied to each element (fail-safe valve B, switch valve, DCCV, LR solenoid valve, LR pressure control valve).
^ The fail-safe valve B moves to the left side by the line pressure.
^ The switch valve moves to left side by the line pressure, and the line pressure through the LR pressure control valve is supplied to the LR brake through the fail-safe valve A.
^ The line pressure is supplied to the DCCV, so the DCCV remains in the right side.
^ The fail-safe valve A moves to the right side by the line pressure through the switch valve.
^ The line pressure is supplied to the LR pressure control valve and the LR solenoid valve, and TCM (PCM) turns off the LR solenoid valve, and the line pressure is supplied to the LR brake through the LR pressure control valve and the switch valve and the fail-safe valve A.
^ The regulator valve moves to the right side due to the lock of line pressure through the manual valve, and the line pressure is higher than in the other gear ranges.