2005 MITSUBISHI 380 Workshop Manual

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-22
7 Transmission
range: 3 (on a
flat and straight
road)Transmission range
and vehicle speed
(1) Driving at speed
of 60 km/h in 3rd
gear
(2) Driving at
constant speed of 60
km/h
(3) Release
accelerator pedal
(Speed under 50
km/hData list No.17
(2) 70
99.6%
(3) 70
99.6% to 0%Damper
control
clutch
solenoid
valve duty
%Damper control
clutch solenoid
system
(P.23A-185,
P.23A-201,
P.23A-204).
Data list No.10
(2) 100 to 300 r/min
(3) The value
changes from (2)Damper
control
clutch
amount of
slippage
8 Use the
diagnostic tool
MB991958
(MUT-III sub
assembly) to
stop the
INVECS-II
function
Transmission
range: D (on a
flat and straight
road)(1)Accelerate to 5th
gear at a throttle
position sensor
output of 1.5 V
(accelerator opening
angle of 25%)
(2)Slowly decelerate
to a stop
(3)Accelerate to 5th
gear at a throttle
position sensor
output of 2.5 V
(accelerator opening
angle of 50%)Data list No.11, 6
The shifting points
correspond with the
diagnostic tool
display and the TP
sensor voltage
(opening angle) and
output shaft speed,
which are shown in
the standard shift
patternMalfunction
when
shiftingShift shock and
slipping
(P.23A-236).
Does not
shift
according
to
instructionsEarly or late
shifting in all
gears
(P.23A-239).
Early or late
shifting in some
gears
(P.23A-242).
STEP CONDITION
BEFORE
TEST/OPERATIONTEST/OPERATION STANDARD INSPECTION
ITEMINSPECTION
PROCEDURE
PA G E

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-23
Does not
shiftNo diagnostic
trouble code
(P.23A-244).
Input shaft
speed sensor
system
(P.23A-55).
Output shaft
speed sensor
system
(P.23A-72).
8 Use the
diagnostic tool
MB991958
(MUT-III sub
assembly) to
stop the
INVECS-II
function
Transmission
range: D (on a
flat and straight
road)(1) Accelerate from
1st gear to 5th gear.
(2) While driving at
60 km/h in 5th gear,
downshift to 4th gear
(3) While driving at
40 km/h in 4th gear,
downshift to 3rd gear
(4) While driving at
30 km/h in 3rd gear,
downshift to 2nd gear
(5) While driving at
20 km/h in 2nd gear,
downshift to 1st gearData list No.11
(1) 1st
2nd 3rd
4th 5th
(2) 5th
4th
(3) 4th
3rd
(4) 3rd
2nd
(5) 2nd
1stDoes not
shift from 1
to 2 or 2 to
1Low-reverse
solenoid valve
system
(P.23A-133).
Second
solenoid valve
system
(P.23A-154).
1st gear
incorrect ratio
(P.23A-196).
2nd gear
incorrect ratio
(P.23A-196).
Does not
shift from 2
to 3 or 3 to
2Second
solenoid valve
system
(P.23A-154).
Overdrive
solenoid valve
system
(P.23A-164).
2nd gear
incorrect ratio
(P.23A-196).
STEP CONDITION
BEFORE
TEST/OPERATIONTEST/OPERATION STANDARD INSPECTION
ITEMINSPECTION
PROCEDURE
PA G E

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-24
3rd gear
incorrect ratio
(P.23A-196).
Does not
shift from 3
to 4 or 4 to
3Low-reverse
solenoid valve
system
(P.23A-133).
Reduction
solenoid valve
system
(P.23A-154).
3rd gear
incorrect ratio
(P.23A-196).
4th gear
incorrect ratio
(P.23A-196).
Does not
shift from 4
to 5 or 5 to
4Underdrive
solenoid valve
system(
23A-200).
Second
solenoid valve
system
(P.23A-154).
4th gear
incorrect ratio
(P.23A-196).
5th gear
incorrect ratio
(P.23A-196).
STEP CONDITION
BEFORE
TEST/OPERATIONTEST/OPERATION STANDARD INSPECTION
ITEMINSPECTION
PROCEDURE
PA G E

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-25
TORQUE CONVERTER STALL TESTM1231005400362
This test measures the maximum engine speed when the
selector lever is in the "D" or "R" position and the torque con-
verter stalls. This tests the operation of the torque converter,
starter motor and one-way clutch operation, as well as the hold-
ing performance of the clutches and brakes in the transmission.
Do not let anyone stand in front of or behind the vehi-
cle while this test is performed.
1. Check the transmission fluid level and temperature. Check
the engine coolant temperature.
Transmission fluid level: At the "HOT" mark on the dipstick
Transmission fluid temperature: 70 80C
Engine coolant temperature: 80 100C
NOTE: Measures transmission fluid temperature with
diagnostic tool MB991958 (MUT-III sub assembly).
2. Check both rear wheels.
3. Pull the parking brake lever on, with the brake pedal fully
depressed.
4. Start the engine. 9 Transmission
range: N (on a
flat and straight
road)Monitor data list
No.22 and No.23
with the diagnostic
tool MB991958
(MUT-III sub
assembly)
(1) Move selector
lever to R range,
drive at constant
speed of 10 km/hThe ratio between
data list No.22 and
No.23 should be the
same as the gear
ratio when reversing.Does not
shiftInput shaft
speed sensor
system
(P.23A-55).
Output shaft
speed sensor
system
(P.23A-72).
Reverse gear
incorrect ratio
(P.23A-196).
STEP CONDITION
BEFORE
TEST/OPERATIONTEST/OPERATION STANDARD INSPECTION
ITEMINSPECTION
PROCEDURE
PA G E

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-26
The throttle should not be fully open for any more than
five seconds.
If you repeat the stall test when the transmission fluid
temperature is greater than 80
C, move the selector
lever to the "N" position and let the engine run at
approximately 1,000 r/min for at least one minute. Wait
until the transmission fluid temperature returns to 80
C
or less.
5. Move the selector lever to the "D" position. Fully depress the
accelerator pedal and read the maximum engine speed at
this time.
Standard value: Stall speed: 2,100
2,600 r/min
6. Move the selector lever to the "R" position. Fully depress the
accelerator pedal and read the maximum engine speed.
Standard value: Stall speed: 2,100
2,600 r/min
TORQUE CONVERTER STALL TEST JUDGMENT
RESULTS
1. Stall speed is too high in both "D" and "R" range
Malfunction of the torque converter (Slippage on the splines
of the torque converter and the input shaft)
Low line pressure
Low-reverse brake slippage and malfunction of the one-way
clutch
2. Stall speed is too high in "D" range only
Underdrive clutch slippage
3. Stall speed is too high in "R" range only
Reverse clutch slippage
4. Stall speed is too low in both "D" and "R" ranges
Malfunction of the torque converter (Slippage of the
one-way clutch)
Insufficient engine output
HYDRAULIC PRESSURE TESTSM1231005500392
The transmission fluid temperature should be between 70
80C during the test.
1. Check the transmission fluid level and temperature. Check
engine coolant temperature.
Transmission fluid level: "HOT" mark on the dipstick
Transmission fluid temperature: 70 80C
Engine coolant temperature: 80 100C
2. Raise the vehicle so that the wheels are free to turn.

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-27
3. Connect the special tools (3.0 MPa (427 psi) oil pressure
gauge [MD998330] and adapters [MD998332, MD998900])
to each pressure discharge port.
NOTE: .
2ND: Second brake pressure port
UD: Underdrive clutch pressure port
LR: Low-reverse brake pressure port
DR: Torque converter release pressure port
DA: Torque converter apply pressure port
RV: Reverse clutch pressure port
OD: Overdrive clutch pressure port
DIR: Direct clutch pressure port
RED: Reduction clutch pressure port
4. Restart the engine.
5. Check that there are no leaks around the special tool port
adapters.
6. Measure the hydraulic pressure at each port under the
conditions given in the standard hydraulic pressure table,
and check that the measured values are within the standard
value ranges.
7. If the pressure is not within the standard value, stop the
engine and refer to the hydraulic pressure test diagnosis
table.
8. Remove the O-ring from the port plug and replace it.
9. Remove the special tool, and install the plugs to the
hydraulic pressure ports.
10.Start the engine and check that there are no leaks around
the plugs.

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-28
STANDARD HYDRAULIC PRESSURE TABLE

NOTE: When the torque converter pressure is measured, the engine speed should be 1,500 r/min or less.
HYDRAULIC PRESSURE TEST DIAGNOSIS TABLE
MEASUREMENT
CONDITIONSSTANDARD HYDRAULIC PRESSURE kPa
SELECT-
OR
LEVER
POS’N SHIFT
RANGE
POSITIO
NENGINE
SPEED
(r/min)UNDERDRIVE
CLUTCH
PRESSURE
[UD]REVERSE
CLUTCH
PRESSURE
[RV]OVERDRIVE
CLUTCH
PRESSURE
[OD]DIRECT
CLUTCH
PRESSURE
[DIR]LOW-
REVERSE
BRAKE
PRESSURE
[LR]SECOND
BRAKE
PRESSURE
[2ND]TORQUE
CONVERTER
PRESSURE
[DR]
P2,500260 360260 360
R Rev. 2,500
12701770 12701770 500 730
N
2,500260 360 220 360
Spo rt
mode1st 2,500 980
1050 980 1050 500 730
2nd 2,500 980
1050 980 1050 500 730
3rd 2,500 780
900 780 900 450 720
4th 2,500 780
900 780 900 780 880 450 720
5th 2,500
780 900 780 880 780 880 450 720
SYMPTOM PROBABLE CAUSE
All hydraulic pressures are high. Malfunction of the regulator valve
All hydraulic pressures are low. Malfunction of the oil pump
Clogged internal oil filter
Clogged oil cooler
Malfunction of the regulator valve
Malfunction of the relief valve
Incorrect valve body installation
Improperly installed solenoid valves
Damaged solenoid valve O-rings
Hydraulic pressure is abnormal
in reverse gear only.Malfunction of the regulator valve
Clogged orifice
Incorrect valve body installation
Hydraulic pressure is abnormal
in 3rd or 4th gear only.Malfunction of the overdrive solenoid valve
Malfunction of the overdrive pressure control valve
Malfunction of the regulator valve
Malfunction of the switch valve
Clogged orifice
Incorrect valve body installation

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-29
Only underdrive clutch hydraulic
pressure is abnormal.Malfunction of the oil seal K
Malfunction of the oil seal L
Malfunction of the oil seal M
Malfunction of the underdrive solenoid valve
Malfunction of the underdrive pressure control valve
Malfunction of the check ball
Clogged orifice
Incorrect valve body installation
Malfunction of the accumulator for underdrive clutch
Only reverse clutch hydraulic
pressure is abnormal.Malfunction of the oil seal A
Malfunction of the oil seal B
Malfunction of the oil seal C
Clogged orifice
Incorrect valve body installation
Only overdrive clutch hydraulic
pressure is abnormal.Malfunction of the oil seal D
Malfunction of the oil seal E
Malfunction of the oil seal F
Malfunction of the overdrive solenoid valve
Malfunction of the overdrive pressure control valve
Malfunction of the check ball
Clogged orifice
Incorrect valve body installation
Malfunction of the accumulator for overdrive clutch
Only direct clutch hydraulic
pressure is abnormal.Malfunction of the oil seal R, S or T
Malfunction of the low-reverse solenoid valve(also used for direct clutch)
Malfunction of the low-reverse pressure control valve
Malfunction of the switch valve
Malfunction of the fail safe valve C
Clogged orifice
Incorrect valve body installation
Only low-reverse brake
hydraulic pressure is abnormal.Malfunction of the oil seal I
Malfunction of the oil seal J
Malfunction of the low-reverse solenoid valve
Malfunction of the low-reverse pressure control valve
Malfunction of the switch valve
Malfunction of the fail safe valve A
Malfunction of all the check balls
Clogged orifice
Incorrect valve body installation
Malfunction of the accumulator for low-reverse brake SYMPTOM PROBABLE CAUSE