2005 MITSUBISHI 380 Ignition

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-17
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
1. Connect diagnostic tool MB991958 to the data link
connector.
2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it
matches the vehicle whose CAN bus lines will be
diagnosed.
If they match, go to step 8.
If not, go to step 5.
5. Select the "view vehicle information" button.
6. Enter the vehicle information and select the "OK" button.
7. When the vehicle information is displayed, confirm again
that it matches the vehicle whose CAN bus lines will be
diagnosed.
If they match, go to step 8.
If not, go to step 5.
8. Select the "OK" button.
9. When the optional equipment screen is displayed, choose
the one which the vehicle is fitted with, and then select the
"OK" button.
HOW TO INITIALIZE A/T LEARNING VALUEM1231022600121
AIM
The use of EEPROM has enabled the A/T learned
value to be retained even after the battery terminals
are disconnected. However, the learned value should
be initialized if the A/T assembly, the engine assem-
bly, the valve body assembly or the solenoid valves
are replaced. The initialization procedure is as
below:
INITIALIZATION PROCEDURE
1. Shift the selector lever to the P range and turn the
ignition switch to the LOCK (OFF) position. Then,
connect the MUT-III to the diagnosis connector.
2. Initialize the learned value on the initialization
screen.
3. After this initialization, make the system learn the
idling in accordance with "Learning procedure for
idling in MPI engine" (Refer to GROUP 00

Precautions before Service 00-22).

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-18
FAIL-SAFE/BACKUP FUNCTIONM1231008300234
When a malfunction of a main sensor or actuator is
detected by the A/T-ECU, the transmission is con-
trolled by pre-set control logic to maintain safe condi-
tions for driving.The following table shows how the fail-safe/backup
function affects vehicle driveability and operation.
MALFUNCTIONING ITEM JUDGEMENT
CONDITIONCONTROL DEFAULT DURING MALFUNCTION
Input shaft speed sensor If no output pulse
from the input shaft
speed sensor is
detected for one
second or more
when the vehicle
speed is 30 km/h (19
mph) or greater.The diagnostic trouble code is recorded when the
malfunction occurs during 4 monitoring periods in
one drive cycle. When the judgment condition is
met, the transmission holds 3rd gear or 2nd gear,
depending on speed, as a fail-safe.
Output shaft speed sensor The output signal
from the output shaft
speed sensor is not
present for one
second or more
while the vehicle is
driven.The diagnostic trouble code is recorded when the
malfunction occurs during 4 monitoring periods in
one drive cycle. When the judgment condition is
met, the transmission holds 3rd gear or 2nd gear,
depending on speed, as a fail-safe.
Low-reverse solenoid valve Solenoid valve
resistance is below
2.7 ohms for 0.32
seconds.The diagnostic trouble code is recorded when the
malfunction occurs during 5 monitoring periods in
one drive cycle. When the judgment condition is
met, the A/T control relay is turned off. The
transmission will only operate in 3rd and reverse
gears until the system is repaired. Underdrive solenoid valve
Second solenoid valve
Overdrive solenoid valve
Reduction (RED) solenoid valve
Damper control clutch (DCC)
solenoid valve
Incomplete shifting 1st The gear ratio value
from the output shaft
speed sensor is not
the same as the
output from the input
shaft speed sensor
for one second after
shifting has been
completed.The diagnostic trouble code is recorded when the
malfunction occurs during 5 monitoring periods in
one drive cycle. When the judgment condition is
met, the A/T control relay is turned off. The
transmission will only operate in 3rd and reverse
gears until the system is repaired. 2nd
3rd
4th
5th
Reverse
A/T control relay A/T control relay
voltage is less than
seven volts for 0.1
second after the
ignition switch is
turned "ON."The A/T control relay is switched off. The
transmission will only operate in 3rd and reverse
gears until the system is repaired.
Malfunction in the A/T-ECU Malfunction has
occurred in the
A/T-ECU.The A/T control relay is switched off. The
transmission will only operate in 3rd and reverse
gears until the system is repaired.

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-19
ROAD TESTM1231007800407
Check using the following procedures.
STEP CONDITION
BEFORE
TEST/OPERATIONTEST/OPERATION STANDARD INSPECTION
ITEMINSPECTION
PROCEDURE
PA G E
1 Ignition switch:
(LOCK) OFFIgnition switch
(1) ONData list No.8
(1) Control Relay
Voltage [V]A/T Control
relay
output
voltageA/T Control
relay system
(P.23A-207).
2 Ignition switch:
ON
Engine: Stopped
Transmission
range: PTransmission range
(1) P, (2) R, (3) N, (4)
DData list No.34
(1) P, (2) R, (3) N, (4)
DTransmissi
on range
switchTransmission
range switch
system
(P.23A-97,
P.23A-119).
Transmission range
(1) D (1st gear)
(2) Select the sport
mode (1st gear)
(3) Upshift and hold
the selector lever in
that position (2nd
gear)
(4) Downshift and
hold the selector
lever in that position
(1st gear)Data list No.27
(1) OFF, (2) ON, (3)
ON, (4) ON
Data list No.28
(1) OFF, (2) OFF, (3)
ON, (4) OFF
Data list No.29
(1) OFF, (2) OFF, (3)
OFF, (4) ONSelect
switch and
Shift switchShift switch
assembly
system
(P.23A-252).
Brake pedal
(1) Depressed
(2) ReleasedData list No.19
(1) ON
(2) OFFSto pl amp
switchSt o pla mp
switch system
(P.23A-89).
3 Ignition switch:
ST
Engine: StoppedCranking test with
lever in P or N rangeCranking should be
possibleCranking Engine does
not crank
(P.23A-218).
4 Engine warming
upDrive for 15 minutes
or more so that the
transmission fluid
temperature
becomes 70
90CData list No.7
Gradually rises to 70
90CTransmissi
on fluid
temperatur
e sensorTransmission
fluid
temperature
sensor system
(P.23A-36,
P.23A-47).
5 Engine: Idling
Transmission
range: NBrake pedal (Retest)
(1) Depressed
(2) ReleasedData list No.19
(1) ON
(2) OFFSto pl amp
switchSt o pla mp
switch system
(P.23A-89).
Transmission range
(1) N
D
(2) N
RShould be no
abnormal shift
shocks
Time delay when
engaging should be
within 2 secondsMalfunction
when
startingEngine stalls
when moving
selector lever
from N to D or
N to R
(P.23A-227).

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-34
DIAGNOSTIC TROUBLE CODE CHARTM1231007900330
During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion, confirm all systems for DTC code(s).
If DTC code(s) are set, erase them all.
NOTE: The A/T diagnostic trouble codes are the codes which are set when item "A/T" is selected on
diagnostic tool MB991958 (MUT-III sub assembly). However, the some codes above indicate failure in the
MPI system.A/T DTC
NO.DIAGNOSIS ITEM REFERENCE
PA G E
P0713 Transmission fluid temperature sensor system Open circuit
P.23A-36
P0712 Short circuit
P.23A-47
P0715 Input shaft speed sensor system Short circuit/open circuit
P.23A-55
P0720 Output shaft speed sensor system Short circuit/open circuit
P.23A-72
Stoplamp switch systemShort circuit
P.23A-89
P0705 Transmission range switch system Open circuit
P.23A-97
Short circuit
P.23A-119
P0753 Low-reverse solenoid valve system Short circuit/open circuit
P.23A-133
P0758 Underdrive solenoid valve system Short circuit/open circuit
P.23A-144
P0763 Second solenoid valve system Short circuit/open circuit
P.23A-154
P0768 Overdrive solenoid valve system Short circuit/open circuit
P.23A-164
P0773 Reduction (RED) solenoid valve system Short circuit/open circuit
P.23A-174
P0743 Damper clutch control (DCC) solenoid valve
systemShort circuit/open circuit
P.23A-185
P0731 1st gear incorrect ratio
P.23A-196
P0732 2nd gear incorrect ratio
P.23A-196
P0733 3rd gear incorrect ratio
P.23A-196
P0734 4th gear incorrect ratio
P.23A-196
P0735 5th gear incorrect ratio
P.23A-196
P0736 Reverse gear incorrect ratio
P.23A-196
P0741 Damper clutch control (DCC) system Defective system
P.23A-201
P0742 Clutch stuck on
P.23A-204
P1751 A/T control relay system Short circuit to ground/open
circuitP.23A-207

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-35
SYMPTOM CHART M1231008000277
During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion, confirm all systems for DTC code(s).
If DTC code(s) are set, erase them all.
SYMPTOM INSPECTION
PROCEDURE NO.REFERENCE
PA G E
Communication with diagnostic
tool is not possibleCommunication with all systems
is impossible- Group 13B
Symptom
Procedures
13A-539.
Communication with the
A/T-ECU only is impossible- Group 13B
Symptom
Procedures
13A-541.
Driving impossible Engine does not start 1
P.23A-218
Does not move forward 2
P.23A-220
Does not move backward 3
P.23A-223
Does not move (forward and
backward)4
P.23A-226
Malfunction when moving
selector into gearEngine stalls when moving
selector lever from "N" to "D" or
"N" to "R"5
P.23A-227
Shift shock when shifting from
"N" to "D" and long delay6
P.23A-229
Shift shock when shifting from
"N" to "R" and long delay 7
P.23A-232
Shift shock when shifting from
"N" to "D" and "N" to "R" and
long delay 8
P.23A-235
Malfunction when shifting Shift shock and slipping 9
P.23A-236
Does not shift properly Early or late shifting in all gears 10
P.23A-239
Early or late shifting in some
gears11
P.23A-242
Does not shift No diagnostic trouble codes 12
P.23A-244
Malfunction while driving Poor acceleration 13
P.23A-248
Vibration 14
P.23A-250
Shift switch assembly system 15
P.23A-252
Shift position indicator light system 16
P.23A-269

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-37
STEP 1. Using diagnostic tool MB991958, check data list
item 7: Transmission Fluid Temperature Sensor.
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Connect diagnostic tool MB991958 to the data link
connector.
(2) Start the engine.
(3) Set diagnostic tool MB991958 to the data reading mode.
Item 7: Transmission Fluid Temperature Sensor.
When the engine is cool: Diagnostic tool display is
almost equal to the ambient temperature (atmo-
spheric temperature)
NOTE: Set diagnostic tool MB991958 to the Engine
MPI data list reading mode for item number 5, Intake
Air Temperature (IAT) Sensor and note the tempera-
ture measurement. When the engine is cool, the
temperature should be almost equal to the ambient
temperature (atmospheric temperature), and the IAT
sensor measurement should be approximately the
same as the Transmission Fluid Temperature Sen-
sor.
When the engine is warm, at approximately running
temperature: 70
80C.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunction P.00-14.
NO : Go to Step 2.

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-38
STEP 2. Measure the sensor output voltage at the A/T
control solenoid valve assembly connector B-108 by
backprobing.
(1) Do not disconnect connector B-108.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground by
backprobing.
When transmission fluid temperature is 20C, voltage
should measure between 3.8 and 4.0 volts.
When transmission fluid temperature is 40C, voltage
should measure between 3.2 and 3.4 volts.
When transmission fluid temperature is 80C, voltage
should measure between 1.7 and 1.9 volts.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage within the specified range?
YES : Go to Step 6.
NO : Go to Step 3.
STEP 3. Measure the ground voltage at the A/T control
solenoid valve assembly connector B-108 by backprobing.
(1) Do not disconnect connector B-108.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 2 and ground by
backprobing.
The voltage should measure 0.5 volt or less.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage 0.5 volt or less?
YES : Go to Step 4.
NO : Go to Step 7.

AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-39
STEP 4. Check the sensor output voltage at A/T control
solenoid valve assembly connector B-108.
(1) Disconnect connector B-108 and measure at the harness
side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground.
The voltage should measure between 4.5 and 4.9 volts.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.5 and 4.9 volts?
YES : Go to Step 5.
NO : Go to Step 9.