Maxima SE V6-3.0L (VQ30DE) (1998)
Torque converter clutch control valve operation
Lock-Up Released
The OFF-duration of the torque converter clutch solenoid valve is long, and pilot pressure is high. The pilot pressure pushes the end face of the torque
converter clutch control valve in combination with spring force to move the valve to the left. As a result, converter pressure is applied to chamber A
(torque converter clutch piston release side). Accordingly, the torque converter clutch piston remains unlocked.
Lock-Up Applied
When the OFF-duration of the torque converter clutch solenoid valve is short, pilot pressure drains and becomes low. Accordingly, the control valve
moves to the right by the pilot pressure of the other circuit and converter pressure. As a result, converter pressure is applied to chamber B, keeping the
torque converter clutch piston applied.
Also smooth lock-up is provided by transient application and release of the lock-up.
General Description
DESCRIPTION
The torque converter clutch solenoid valve is activated, with the gear in "D4" by the TCM in response to signals sent from the vehicle speed and throttle
position sensors. Lock-up piston operation will then be controlled.
Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine
speed, there is no lock-up.
Line Pressure Control
LINE PRESSURE CONTROL
TCM has the various line pressure control characteristics to meet the driving conditions.
An ON-OFF duty signal is sent to the line pressure solenoid valve based on TCM characteristics.
Hydraulic pressure on the clutch and brake is electronically controlled through the line pressure solenoid valve to accommodate engine torque. This
results in smooth shift operation.