Chrysler PT Cruiser 2001 Service Manual Supplement page 2758

GENERAL INFORMATION
Name of code: P-0750(41) — L-R Solenoid Circuit
P-0755(42) — 2-4 Solenoid Circuit
P-0760(43) — OD Solenoid Circuit
P-0765(44) — UD Solenoid Circuit
When monitored: Ignition key is turned from
''off '' position to ''run'' position and/or ignition key is
turned from ''crank'' position to ''run'' position, then
every 10 seconds thereafter, or when a speed ratio
or pressure switch error fault is detected.
Set condition: All four solenoids are tested for
continuity continuously immediately upon start up
and during vehicle operation. For solenoids that are
currently energized, power is momentarily inter-
rupted, then reenergized. For solenoids that are not
currently energized, the solenoid is momentarily
energized, then de-energized. Under both situa-
tions, if an inductive spike is not sensed by the
Transmission Control Module (TCM) during the
continuity check, it is retested twice. IF it fails the
test the third time, the appropriate code is set.
Gear UD OD
Park
Reverse X
Neutral
1st X
2nd X
3rd X X
4th X
Theory of operation: Four solenoids are used to
control the friction elements (clutches). The conti-
nuity of the solenoids circuits are periodically
tested. Each solenoid is turned on or off depending
on it's current state. An inductive spike should be
detected by the TCM during this test. If no spike is
detected, the circuit is tested agin to verify the
failure. In addition to the periodic testing, the
solenoid circuts are tested if a speed ratio or pres-
sure switch error occurs. In this case, one failure
will result in the appropriate code being set.
Transmission Effects: The MIL will illuminate
and the transmission goes into neutral if code is set
above 22 MPH, limp-in mode when vehicle speed is
below 22 MPH.
Possible causes:
> Open or shorted solenoid circuit(s) between TCM
and solenoid pack.
> Open ground circuit.
> TCM connector problems
> Solenoid pack connector problem.
> Solenoid Pack
> TCM
Name of code: P-1776(47) — Solenoid Switch
Valve (SSV) Latched in L-R Position
When monitored: Continuously when doing par-
tial or full EMCC (PEMCC or FEMCC)
REV 2-4 L-R
X
X
X
X
X
X
10
Set condition: If the transmission senses the L-R
prssure switch closing while performing PEMCC or
FEMCC. This code will be set after two unsuccess-
ful attempts to perform PEMCC or FEMCC.
Theory of operation: The solenoid switch valve
(SSV) controls the direction of th transmission fluid
when the L-R/TCC solenoid is energized. SSV will
be in the downshifted position in 1st gear, thus
directing the fluid to the L-R clutch circuits. In 2nd,
3rd, and 4th, the SSV will be in the downshifted
position and directs the fluid into the torque con-
verter cluch (TCC).
When doing PEMCC or FEMCC, the L-R pressure
switch should indicate no pressure if the SSV is in
the TCC position. If the L-R pressure switch indi-
cats pressure while in PEMCC or FEMCC, EMCC
operation is aborted and inhibited to avoid inad-
vertent application of the L-R clutch. Partial EMCC
will be attempted if the L-R pressure switch does
not indicate pressure. A second direction of L-R
pressure results in setting the code.
Transmission Effects: At speeds above 45 MPH,
EMCC is inhibited. Once speed falls below 45 MPH,
the transmission will go into relay open limp-in
mode and the MIL will illuminate.
Possible causes:
> Valve body - Solenoid valve stuck in L-R position
> Intermittent short to ground or open circuit in
L-R Pressure Switch Sense circuit (with code 24
only)
> Solenoid pack (with code P-1784(24) only)
> TCM (with code P-1784(24) only)
Name of code: P-1793(48) — Torque Reduction
(TRD) Link Communication Error
When monitored: Whenever the engine is run-
ning.
Set condition: This code is set when the TCM
sends multiple torque reduction messages to the
PCM and the TCM does not receive a response from
the PCM.
Theory of operation: During high torque shifts
the TCM will send a message requesting that the
PCM reduce engine power until the shift is com-
pleted. This message is sent from the TCM to the
Powetrain Control Module across the Torque Man-
agement Request Sense Circuit. The PCM will
acknowledge the TCM's request by sending a mes-
sage across the PCI bus within a specific amount of
time. The TRD Link communication is also tested
periodically for operation whenever the engine is
running and the vehicle is not moving with zero
degrees throttle.
Transmission Effects: Maximum throttle angle
used by TCM will be 54 degrees. As a result a
customer may complain about loss of performance
or of short shifting when driving aggressively.