Mitsubishi Eclipse. Technical Information Manual (1994) — part 44

POWER TRAIN

Automatic Transaxle

Reverse

With the manual valve moved to the reverse position,
line pressure is allowed through the manual valve
directly to the reverse clutch and also through the

solenoid to the low/reverse clutch. The regu-

lator valve is designed to increase line pressure
in the reverse gear range above the pressure that
is normal for other ranges. This is done to increase

clutch capacity. Line pressure is directed between
a small valve and larger valve at the right end of

the regulator valve. This neutralizes the effects of
the larger valve on the regulator valve. With only
the smaller valve working against the regulator
valve, the regulator valve spring further closes down
the vent, causing line pressure to increase. There
are no solenoids energized in the reverse gear
range. However, the

solenoid is modulated

during initial engagement to smooththe torque tran-
sition and prevent harsh engagement into reverse.

REVERSE

REVERSE

LR Low reverse
UD Underdrive

Reverse

AC Accumulator

PT Pressure tap

Solenoid

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

POWER TRAIN

Automatic Transaxle

Reverse Block Above Eight MPH
Reverse gear will not engage if the TCM senses

vehicle speed above eight mph. This is to prevent
damage that could occur if a driver accidentally

puts the gear selector in

while rolling in any

forward gear range. If the output speed sensor de-
tects that the output shaft is spinning at a speed
equal to or greater than eight mph, the TCM activates

reverse block to protect the transaxle. The function

REVERSE BLOCK

Shift to Rev. w/speed over 8 mph

REVERSE BLOCK

SHIFT TO REV. Y/SPEED OVER 8 MPH

is inoperable in “limp-in” mode. To accomplish or
initiate reverse block, the TCM energizes the
solenoid. The solenoid prevents line pressure from
applying the low/reverse clutch. Without a holding
element, the planetary

in this range will

provide no output. It must have both an input and
a holding element to provide output. In this condition,

the transaxle is effectively in Neutral.

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

First Gear

When any of the forward gear selections are made,
line pressure is directed to all four solenoids. In
first gear the TCM will energize the

and

solenoids. This action applies the

verse and underdrive clutches. The forward gear
position selected by the driver has no effect on
manual valve position. Its location will be the same

for all forward positions. The selection difference
is detected by the TCM through the transmission
range and park/neutral position switches. The
switches provide the TCM with the information
ed to determine which shift pattern and schedule

to use for the selected gear range.

FIRST GEAR

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

FIRST GEAR

II II

POWER TRAIN

Automatic Transaxle

Second Gear

There are no solenoids energized in second gear.

clutch engagement. When the TCM recognizes a

With the solenoids de-energized, line pressure is

problem or is unable to function properly, the

directed to the 2-4 and underdrive clutches. Line

axle goes into a default or limp-in mode. In this

pressure from the 2-4 clutch circuit is also directed

mode of operation, the solenoids and valve body

to the solenoid switch valve, which moves the valve

shift to a position that only provides second gear

to the left. When the solenoid switch valve is moved

range, regardless of any forward gear that is

to this position, it opens a circuit that can be applied

by the driver.

by the TCM and LWCC solenoid for torque converter

SECOND GEAR

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

SECOND GEAR

.