Chrysler PT Cruiser 2001 Service Manual Supplement page 2749

1.0 INTRODUCTION
The procedures contained in this manual include
all of the specifications, instructions, and graphics
needed to diagnose 41TE Electronic Automatic
Transaxle (EATX) problems. The diagnostics in this
manual are based on the failure condition or symp-
tom being present at the time of diagnosis.
When repairs are required, refer to the appropri-
ate volume of the service manual for the proper
removal and repair procedure.
Diagnostic procedures change every year. New
diagnostic systems may be added and/or carryover
systems may be enhanced. READ THIS MANUAL
BEFORE TRYING TO DIAGNOSE A VEHICLE
TROUBLE CODE. It is recommended that you
review the entire manual to become familiar with
all new and changed diagnostic procedures.
This book reflects many suggested changes from
readers of past issues. After using this book, if you
have any comments or recommendations, please fill
out the form at the back of the book and mail it back
to us.
1.1 SYSTEM COVERAGE
This diagnostic procedures manual covers all
2001 MY PT series vehicles.
1.2 SIX-STEP TROUBLESHOOTING
PROCEDURE
Diagnosis of the 41TE electronic transaxle is done
in six basic steps:
•
verification of complaint
• verification of any related symptoms
• symptom analysis
•
problem isolation
•
repair of isolated problem
• verification of proper operation
2.0 IDENTIFICATION OF
SYSTEM
All 2001 MY PT Cruiser series vehicles are
equipped with a 41TE Automatic Transaxle.
3.0 SYSTEM DESCRIPTION AND
FUNCTIONAL OPERATION
3.1 GENERAL DESCRIPTION
The 41TE electronic transaxles is a conventional
transaxle in that it uses hydraulically applied
GENERAL INFORMATION
clutches to shift a planetary gear train. However,
the electronic control system replaces many of the
mechanical and hydraulic components used in con-
ventional transmission valve bodies.
3.2 FUNCTIONAL OPERATION
The 41TE electronic transaxle has a fully adap-
tive control system. The system performs it's func-
tions based on continuous real-time sensor feedback
information. The control system automatically
adapts to changes in engine performance and fric-
tion element variations to provide consistent shift
quality. The control system ensures that clutch
operation during upshifting and downshifting is
more responsive without increased harshness.
The Transmission Control Module (TCM) contin-
uously checks for electrical problems, mechanical
problems, and some hydraulic problems. When a
problem is sensed, the TCM stores a diagnostic
trouble code. Some of these codes cause the tran-
saxle to go into ''limp-in'' or ''default'' mode. While in
this mode, electrical power is taken away from the
transaxle via the TCM, de-energizing the transmis-
sion control relay, and taking power from the sole-
noid pack. When this happens, the only transaxle
functions are:
• Park and Neutral
•
Reverse
•
Second Gear
No upshifts or downshifts are possible. The posi-
tion of the manual valve alone allows the three
ranges that are available. Although vehicle perfor-
mance is seriously degraded while in this mode, it
allows the owner to drive the vehicle in for service.
Once the DRBIII is in the ''EATX'' portion of the
diagnostic program, it constantly monitors the
TCM to see if the system is in limp-in mode. If the
transaxle is in limp-in mode, the DRBIII will flash
the red LED.
3.2.1 AUTOSTICK FEATURE
The feature allows the driver to manually shift
the transaxle when the shift lever is pulled back
into the AutoStick position. When in AutoStick, the
instrument cluster displays the current gear.
3.2.2 TRANSMISSION OPERATION AND
SHIFT SCHEDULING AT VARIOUS
OIL TEMPERATURES
The transmission covered in this manual has
unique shift schedules depending on the tempera-
ture of the transmission oil. The shift schedule is
modified to extend the life of the transmission while
operating under extreme conditions.
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