Chrysler PT Cruiser 2001 Service Manual Supplement page 2757

caused by a lack of pump prime.
Transmission Effects: Vehicle will not move or
transmission slips. Normal operation will continue
if pump prime returns.
Possible causes:
> Low transmission fluid level
> PRNDL indicates a valid OD code in the hydrau-
lic reverse position
> Transmission fluid filter clogged or damaged
> Transmission fluid filter improperly installed
(Bolts loose or O-ring missing)
> Oil pump - If a customer has a problem when the
transmission is cold whereby he shifts to reverse,
gets reverse, and then shifts to OD and does not
get OD (gets a neutral condition), and then can
not get reverse or OD for between 3-20 seconds,
replace the oil pump. High side clearance in the
oil pump will set a code 35. The pump will prime
upon start-up, but as the torque converter purges
air (drain down) the air will leak across the inner
rotor into the pump suction port and cause a loss
of prime right after the shift into OD. After 3-20
seconds, pump prime will return and normal
operation will continue. The pump should be
replaced only after all other possible causes
above have been checked and verified.
Name of code: P-1790(36) — Fault Immediately
Afer Shift
When monitored: After a speed ratio error is
stored.
Set condition: This code is set if the associated
speed ratio is stored within 1.3 seconds after a shift.
Theory of operation: This code will only be
stored along with a 50 series code. If this code is set,
it indicates the problem is mechanical in nature.
When this code exists, diagnosing the transmission
should be based on the associated speed ratio code
and primarily mechanical causes should be consid-
ered.
Transmission Effects: None
Possible causes:
> Mechanical causes as listed under associated
speed ratio code.
Name of code: P-1775(37) — Solenoid Switch
Valve Latched in TCC Position
When monitored: During an attempted shift into
1st gear.
Set condition: This code is set if three unsuccess-
ful attempts are made to get into 1st gear in one
given key start.
Theory of operation: The solenoid switch valve
(SSV) controls the direction of the transmission
fluid when the L-R/TCC solenoid is energized. The
SSV will be in the downshifted position in 1st gear,
thus directing the fluid to the L-R clutch circuit. In
2nd, 3rd, and 4th, it will be in the upshifted position
GENERAL INFORMATION
and directs the fluid into the torque converter
clutch (TCC).
When shifting into 1st gear, a special hydraulic
sequence is performed to ensure SSV movement
into the downshifted position. The L-R pressure
switch is monitored to confirm SSV movement. If
movement is not confirmed (the L-R pressure
switch does not close), 2nd gear is substituted for
1st.
Transmission Effects: Transmission will have no
1st gear (2nd gear will be substituted), and no
EMCC operation.
Possible causes:
> PRNDL indicates a valid OD code in the hydrau-
lic reverse position
> Valve body - Solenoid valve stuck in TCC position
> High idle speed
> Solenoid malfunction - L-R pressure switch will
not close
> L-R Pressure Switch Sense circuit shorted to
battery
Name of code: P-0740(38) — Torque Converter
Clutch Control Circuit
When monitored: During Electronically Modu-
lated Converter Clutch (EMCC)
Set condition:
a) The transmission must be in EMCC, with the
input speed greater than 1750 RPM. The TCC/L-R
solenoid must achieve it's maximum duty cycle and
still not be able to pull the engine speed within 60
RPM of input speed.
b) If the transmission is in FEMCC and the en-
gine can clip the TCC by more then 100 RPM
(Engine speed - Input speed) for 10 seconds.
The code will be set if one of these events happens
three times at a throttle angle less than 30 degrees.
Theory of operation: When in 2nd, 3rd, or 4th
gear, the torque converter clutch (TCC) can be
locked when certain conditions are met. The TCC
piston is electronically modulated by increasing the
duty cycle of the L/R/TCC solenoid until the torque
converter slip difference (difference between engine
and turbine speed) is within 60 RPM. Then the
L-R/TCC solenoid is fully energized (FEMCC/100%
duty cycle). Torque converter slip is monitored in
FEMCC to ensure adequate clutch capacity.
Transmission Effects: EMCC will still be avail-
able after code is set. MIL will illuminate after 5
minutes of accumulated slip in FEMCC. The trans
will attempt normal operation (no limp-in) even
after the MIL is illuminated.
Possible causes:
> Worn pump bushing and/or failed torque con-
verter - both should be replaced during a rebuild
with P-0740(38) present
> Solenoid pack
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