Circuit/System Description

The line pressure control solenoid valve is part of the control solenoid valve assembly which has no serviceable components. The normally high line pressure control solenoid valve regulates and directs oil pressure to the pressure regulator valve. Increasing line pressure control solenoid valve pressure increases transmission line pressure. The transmission control module (TCM) varies the current to the line pressure control solenoid valve by controlling the amount of time the low side driver is ON and OFF. Decreasing the ON time, decreases the current to the line pressure control solenoid, which increases line pressure control solenoid oil pressure by closing OFF the solenoid exhaust port. Increasing the current to the line pressure control solenoid decreases line pressure control oil pressure by opening the solenoid exhaust port. Line pressure control solenoid power is supplied by the TCM through a high side driver. The high side driver protects the circuit and components from excessive current flow. If excessive current flow is detected, the high side driver will turn OFF. When the fault is corrected, the high side driver will reset.