General System Description

GENERAL DESCRIPTION
The 41TE and 42LE electronic transaxle are conventional transaxles in that they use hydraulically applied clutches to shift a planetary gear train. However, the electronic control system replaces many of the mechanical and hydraulic components used in conventional transaxles.

FUNCTIONAL OPERATION
The 41TE and 42LE electronic transaxles have a fully adaptive control system. The system performs it's functions based on continuous real-time sensor feedback information. The control system automatically adapts to changes in engine performance and friction 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) continuously 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 transaxle 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 transmission control relay, and taking power from the solenoid pack. When this happens, the only transaxle functions are:
- Park and Neutral
- Reverse
- Second Gear

No upshifts or downshifts are allowed. The position of the manual valve alone allows the three ranges that are available. Although vehicle performance is seriously degraded while in this mode, it allows the owner to drive the vehicle in for service.

Once the DRB or equivalent scan tool 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 DRB will flash the red LED.