Mitsubishi Eclipse. Technical Information Manual (1994) - part 46

POWER TRAIN 

 Automatic Transaxle

Overdrive Gear (Fourth)

The TCM energizes the underdrive solenoid which
shuts off line pressure to the underdrive clutch. The

the 2-4 clutch to engage. This shifts the transaxle

TCM also de-energizes the 2-4 solenoid and allows

into overdrive by allowing only the 2-4 and overdrive

clutches to be applied.

OVERDRIVE

OVERDRIVE

 

 

LR   Low reverse
UD   Underdrive

   Reverse

AC   Accumulator

PT   Pressure tap

S   Solenoid

24   2-4 clutch
OD   Overdrive
SW   Switch
CC   Converter CL
D   Dribbler
V   Vent

 

 

 

   

   

 

 

 

POWER TRAIN 

 Automatic Transaxle

Overdrive Gear EMCC

The EMCC function is the same in Overdrive as

 

I 

was in the second and direct gear positions. For

a review of EMCC operation, refer to second Gear

EMCC.

OVERDRIVE

EMCC

OVERDRIVE

 

 

 

 

 

LR   Low reverse
UD   Underdrive

   Reverse

AC   Accumulator

PT   Pressure tap
S   Solenoid

24   2-4 clutch
OD   Overdrive
SW   Switch
CC   Converter CL

   Dribbler

V   Vent

 

 

 

 

  

__

POWER TRAIN 

 Automatic Transaxle

Overdrive Gear CC On
In this position the torque converter clutch is fully

For a review of the transaxle operation in the CC

engaged (CC On). The LWCC solenoid is fully 
gized as it was in the direct gear CC on position.

on position, refer to Direct Gear CC On.

OVERDRIVE
CC 

ON

LR   Low reverse
UD   Underdrive

   Reverse

AC   Accumulator

PT   Pressure tap
S   Solenoid

24   2-4 clutch
OD   Overdrive

SW   Switch
CC   Converter CL

   Dribbler

V   Vent

OVERDRIVE

CC 

ON

 

 

 

 

 

 

 

 

POWER TRAIN   Automatic Transaxle

Electronic Control System

INTRODUCTION TO THE ELECTRONIC CONTROL SYSTEM

The advantage of using the electronic control system

is more precise control over transaxle function. An
added advantage of the system is that it can help

the technician find a problem in a malfunctioning
transaxle. The system can do this through what

is called On-Board Diagnostics. The Transmission
Control Module (TCM) continuously monitors its criti-

cal functions during normal operation. It records

malfunctions in the form of diagnostic trouble codes
and the number of engine starts since the last code
stored in memory. The technician can use this in-

formation in the event of a malfunction or complaint.

Up to seven, two digit numeric diagnostic trouble
codes may be stored in memory at one time.

When a failure is identified by the TCM, the system

may go into a limp-in mode by turning off the sole-
noids. TCM logic is included to ensure that the 
in event results in an orderly shut-down of transaxle

Electronic Control System
Each of the major system components are repre-

sented as a block of information. The lines between
the blocks represent the flow of input and output

information between the components.
Some of the input and output information is unique

to the TCM. In other words, some of the input to
the TCM is “Direct Input.” Some information (input)
to the TCM is shared with other components through

function when possible. The shut-down sequence
will vary depending on which gear the transaxle

is in and what the vehicle speed is at the time the

failure is identified by the TCM. This “all-solenoids
off” limp-in mode is designed to allow for shift lever

manual control of PARK, REVERSE, NEUTRAL and
SECOND GEAR operation. When any forward gear

shift lever position is chosen, the transaxle will re-

main in second gear range.

All failures do not result in limp-in, just those that
could potentially cause internal transaxle damage.

If the TCM itself fails, the transaxle will also go

into the limp-in mode.

The transaxle control system consists of an electron-

ic control module, called the TCM, and a system
of input and output components, that function togeth-
er to control the operation of the transaxle.

the Chrysler Collision Detection (CCD) data bus.
As the TCM receives input information, it continuous-

ly processes it through its logic circuits in order

to perform all of the control functions that it has
been designed to perform. The following is a list
of inputs related to the transaxle control system,

both direct and indirect.