Legacy Sport Utility LTD AWD F4-2.5L DOHC (1999)
C: SHIFT CONTROL
Gearshifting is controlled in response to driving conditions, according to the shift point characteristic data stored in the TCM. Solenoids are operated
at the proper time corresponding to the shift pattern, throttle position, and vehicle speed for smooth shifting.
NOTE: When oil temperature is below approximately 10°C (50°F), the vehicle cannot be shifted to the 4th gear.
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Control module activates both solenoids 1 and 2 in response to throttle and vehicle speed signals.
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Shift valve moves in response to solenoid operation, supplying/interrupting clutch pressure to the line.
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Gears are shifted by ON-OFF operation of both solenoids as indicated in Table.
D: LOCK-UP CONTROL
The lock-up engaging and disengaging conditions are set for 4th gear shift range, gear position and shift pattern and correspond to the throttle position
and vehicle speed, and the duty solenoid electronically controlled by TCM controls the lock-up clutch. The lock-up clutch engagement and
disengagement are controlled by the lock-up control valve.
<When engaging and disengaging>
The lock-up control valve engages and disengages the lock-up clutch by adjusting the hydraulic pressure.
1. Non-lock-up operation (Except 4th speed of D range)
The duty solenoid B (lock-up) allows the hydraulic pressure from the pilot valve to flow to the lockup control valve end where the spool is pushed
to the "disengaging" position.
The lock-up operating pressure (torque converter clutch regulator pressure) acts on the lock-up clutch disengaging circuit, while the engaging
circuit communicates with the oil cooler circuit. Accordingly, the lock-up clutch is disengaged by the pressure difference.
2. Lock-up operation (4th speed of D range)
The duty solenoid B (lock-up) allows the hydraulic pressure from the pilot valve to flow to the lockup control valve end where the spool is pushed
to the "engaging" position. Then, the hydraulic pressure from the torque converter impeller flows through the valve and acts on the lock-up clutch,
engaging it.
<Smooth control>
The duty solenoid B (lock-up) is controlled by the TCM and controls the operation of the lock-up control valve. Because the lock-up operating
pressure is controlled by the lock-up control valve, the force applied to the lock-up clutch is controlled for smooth clutch operation.