RAM 2500 Truck 2WD V8-5.7L (2008)
Pressure Regulating Solenoid: Description and Operation
42RLE Automatic Transmission
Description
DESCRIPTION
The pressure control solenoid (1) is mounted on the top of the valve body, next to the line pressure sensor (2).
The TCM utilizes a closed-loop system to control transmission line pressure. The system contains a variable force style solenoid, the Pressure Control
Solenoid. The solenoid is duty cycle controlled by the TCM to vent the unnecessary line pressure supplied by the oil pump back to the sump. The system
also contains a variable pressure style sensor, the Line Pressure Sensor, which is a direct input to the TCM. The line pressure solenoid monitors the
transmission line pressure and completes the feedback loop to the TCM. The TCM uses this information to adjust its control of the pressure control
solenoid to achieve the desired line pressure.
Operation
OPERATION
The pressure control solenoid (PCS) is a variable force (VFS) style solenoid. A VFS solenoid is an electro-hydraulic actuator, combining a solenoid and
a regulating valve.
The transmission control module varies the current for the PCS, which varies the pressure in the line pressure hydraulic circuit. When the current (duty
cycle) of the PCS is low, the pressure in the circuit is higher. At 0 current (0% duty cycle), the pressure is at the maximum value. Conversely, when the
current is maximized (100% duty cycle), the pressure in the circuit is at the lowest possible value.
Description
DESCRIPTION
