Mitsubishi Montero (2004+). Manual - part 860

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-15

HOW TO PERFORM ACTUATOR TEST

Required Special Tools:

•  MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "Interactive Diagnosis" from the start-up screen.
4. Select "System select."
5. Choose "ELC-A/T" from the "POWER TRAIN" tab.
6. Select "MITSUBISHI."
7. Select "Actuator Test."
8. Choose an appropriate item and select the "OK" button.

FAIL-SAFE/BACKUP FUNCTION

M1231101100117

When a malfunction of a main sensor or actuator is 
detected by the PCM, the transmission is controlled 
by pre-set control logic to maintain safe conditions 
for driving.

The following table shows how the fail-safe/backup 
function affects vehicle driveability and operation.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-16

MALFUNCTIONING ITEM JUDGMENT CONDITION

CONTROL 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 once 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 and "N" range 
light flashes as a fail-safe.

Output shaft 
speed 
sensor

Output from the output 
shaft speed sensor is 
continuously 50% or less of 
the output from the vehicle 
speed sensor one second 
or more when the vehicle 
speed is 30 km/h (19 mph) 
or more.

The diagnostic trouble code is recorded when the 
malfunction occurs once 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 and "N" range 
light flashes 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 4 monitoring periods in 
one drive cycle. When the judgment condition is 
met, the A/T control relay is turned off and "N" 
range light flashes. 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 
solenoid 
valve
Torque 
converter 
clutch 
solenoid 
valve

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-17

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 4 monitoring periods in 
one drive cycle. When the judgment condition is 
met, the A/T control relay is turned off and "N" 
range light flashes. 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 PCM

Malfunction has occurred in 
the PCM.

The A/T control relay is switched off. The 
transmission will only operate in 3rd and Reverse 
gears until the system is repaired.

MALFUNCTIONING ITEM JUDGMENT CONDITION

CONTROL DEFAULT DURING MALFUNCTION

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-18

ROAD TEST

M1231100800146

Check using the following procedures

STEP CONDITION 

BEFORE TEST/
OPERATION

TEST/
OPERATION

STANDARD

INSPECTION 
ITEM

DTC

INSPECTION 
PROCEDURE 
PAGE

1

Ignition switch: 
OFF

Ignition switch
(1) ON

Data list No.54

(1) Control 

Relay Voltage 
[V]

A/T Control 
relay output 
voltage

54

A/T Control relay 
system 
(

P.23A-277

)

2

Ignition switch: 
ON
Engine: Stopped
Transmission 
range: P

Transmission 
range
(1) P, (2) R, (3) 
N, (4) D

Data list No.61
(1) P, (2) R, (3) 
N, (4) D

Transmission 
range switch

27, 28

Transmission 
range switch 
system 
(

P.23A-121

 , 

P.23A-150

)

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.67
(1) OFF, (2) ON, 
(3) ON, (4) ON
Data list No.68
(1) OFF, (2) OFF, 
(3) ON, (4) OFF
Data list No.69
(1) OFF, (2) OFF, 
(3) OFF, (4) ON

Select switch
Shift switch

-

Shift switch 
assembly system 
(

P.23A-355

)

Shift indicator 
light
(1) "D" and "1" 
illuminates
(2) Only "1" 
illuminates
(3) Only "2" 
illuminates
(4) Only "1" 
illuminates

Accelerator 
pedal
(1) Fully closed
(2) Depressed
(3) Fully open

Data list No.11
(1) 200 

− 800 mV

(2) Gradually 
rises from (1)
(3) 3,800 

− 4,900 

mV

Throttle 
position sensor

−

Group 13A, 
Diagnostic 
Trouble Code 
Procedures 

− 

DTCs P0122, 
0123: Throttle 
Position Sensor 
System 
(

P.13A-138

, 

P.13A-147

).