Intrepid V6-3.5L VIN V (2002)
Shift Solenoid Position Sensor/Switch: Description and Operation
42LE - Automatic Transmission
SOLENOID/PRESSURE SWITCH ASSY
DESCRIPTION
The Solenoid/Pressure Switch Assembly (Fig. 379) is inside the transaxle and mounted to the valve body assembly. The assembly consists of four
solenoids that control hydraulic pressure to the L/R, 2/4, OD, and UD friction elements (transaxle clutches), and the torque converter clutch. The reverse
clutch is controlled by line pressure from the manual valve in the valve body The solenoids are contained within the Solenoid/Pressure Switch Assembly
and can only be serviced by replacing the assembly.
The solenoid assembly also contains pressure switches that monitor and send hydraulic circuit information to the PCM. Likewise, the pressure switches
can only be service by replacing the assembly.
OPERATION
SOLENOIDS
The solenoids receive electrical power from the Transmission Control Relay through a single wire. The PCM energizes or operates the solenoids
individually by grounding the return wire of the solenoid needed. When a solenoid is energized, the solenoid valve shifts, and a fluid passage is opened
or closed (vented or applied), depending on its default operating state. The result is an apply or release of a frictional element.
The 2/4 and UD solenoids are normally applied, which allows fluid to pass through in their relaxed or "off" state. By design, this allows transaxle limp-in
(P,R,N,2) in the event of an electrical failure.
The continuity of the solenoids and circuits are periodically tested. Each solenoid is turned on or off depending on its current state. An inductive spike
should be detected by the PCM during this test. If no spike is detected, the circuit is tested again to verify the failure. In addition to the periodic testing,
the solenoid circuits are tested if a speed ratio or pressure switch error occurs.
PRESSURE SWITCHES
The PCM relies on three pressure switches to monitor fluid pressure in the L/R, 2/4, and OD hydraulic circuits. The primary purpose of these switches is
to help the PCM detect when clutch circuit hydraulic failures occur. The range for the pressure switch closing and opening points is 11-23 psi. Typically
the switch opening point will be approximately one psi lower than the closing point. For example, a switch may close at 18 psi and open at 17 psi.
