SOLENOID-PRESSURE CONTROL
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 con-
trol of the pressure control solenoid to achieve the
desired line pressure.
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.
REMOVAL
1. Remove the valve body from the transmission.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE/VALVE BODY - REMOVAL)
2. Remove the electrical connectors from the pres-
sure control solenoid (1) and the line pressure sen-
sor (2).
3. Remove the screws (6) holding the pressure con-
trol solenoid (1) and line pressure sensor (2) to the
valve body.
4. Remove the pressure control solenoid and line
pressure sensor from the valve body.
21 - 384
AUTOMATIC TRANSMISSION - 42RLE
KJ