Removal - Chrysler Vehicle User Manual

21 - 168 AUTOMATIC TRANSMISSION - 42RLE
SOLENOID/PRESSURE SWITCH ASSY (Continued)
Fig. 237 Valve Body Assembly
1 - SOLENOID/PRESSURE SWITCH ASSEMBLY
2 - TRS
3 - TRANSFER PLATE
4 - SEPARATOR PLATE
5 - VALVE BODY
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 transmission
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 pres-
sure switch error occurs.
PRESSURE SWITCHES
The PCM relies on three pressure switches to mon-
itor 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 clos-
ing 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. The switches
are continuously monitored by the PCM for the cor-
rect states (open or closed) in each gear as shown in
the following chart:
PRESSURE SWITCH STATES
GEAR L/R
R OP
P/N CL
1st CL
2nd OP
D OP
OD OP
OP = OPEN
CL = CLOSED
A Diagnostic Trouble Code (DTC) will set if the
PCM senses any switch open or closed at the wrong
time in a given gear.
The PCM also tests the 2/4 and OD pressure
switches when they are normally off (OD and 2/4 are
tested in 1st gear, OD in 2nd gear, and 2/4 in 3rd
gear). The test simply verifies that they are opera-
tional, by looking for a closed state when the corre-
sponding element is applied. Immediately after a
shift into 1st, 2nd, or 3rd gear with the engine speed
above 1000 rpm, the PCM momentarily turns on ele-
ment pressure to the 2/4 and/or OD clutch circuits to
identify that the appropriate switch has closed. If it
doesn't close, it is tested again. If the switch fails to
close the second time, the appropriate Diagnostic
Trouble Code (DTC) will set.

REMOVAL

NOTE: If the Solenoid/Pressure Switch Assembly is
being replaced, the Quick Learn Procedure must be
performed. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION
MODULE - STANDARD PROCEDURE)
(1) Raise vehicle on hoist.
(2) Remove valve body assembly from transmis-
sion. (Refer to 21 - TRANSMISSION/AUTOMATIC -
42RLE/VALVE BODY - REMOVAL)
(3) Remove Solenoid/Pressure Switch Assembly
retaining screws from solenoid (Fig. 238).
(4) Remove Solenoid/Pressure Switch Assembly
and screen from valve body (Fig. 239).
TJ
2/4 OD
OP OP
OP OP
OP OP
CL OP
OP CL
CL CL
CONTROL