Mitsubishi Montero (2002-2004). Manual - part 875

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-41

128

Low-reverse solenoid 
valve

Engine: Idling
Transmission range: P

Battery positive voltage

Engine: Idling
Gear range: 2nd gear

6 

− 9 V

129

Reduction solenoid 
valve

Engine: Idling
Transmission range: P

Battery positive voltage

Engine: Idling
Gear range: 5th gear

6 

− 9 V

130

Torque converter clutch 
solenoid valve

Engine: Idling
Gear range: 1st gear

Battery positive voltage

131

Ground

Always

1 V or less

134

Shift indicator light: 3rd

Engine: Idling
Gear range: 3rd gear

Battery positive voltage

Engine: Idling
Gear range: Other than 3rd gear

1 V or less

135

Transmission fluid 
temperature warning 
light

Ignition switch: LOCK(OFF) 

→ ON

1 V or less 

→ Battery 

positive voltage (after 
several seconds have 
elapsed)

136

Second solenoid valve

Engine: Idling
Gear range: 2nd gear

Battery positive voltage

Engine: Idling
Transmission range: P

6 

− 9 V

137

Under drive solenoid 
valve

Engine: Idling
Gear range: 1st gear

Battery positive voltage

Engine: Idling
Transmission range: P

6 

− 9 V

138

Overdrive solenoid valve Engine: Idling

Gear range: 3rd gear

Battery positive voltage

Engine: Idling
Transmission range: P

6 

− 9 V

139

Ground

Always

1 V or less

142

Shift indicator light: 4th

Engine: Idling
Gear range: 4th gear

Battery positive voltage

Engine: Idling
Gear range: Other than 4th gear

1 V or less

TERMINAL 
NO.

INSPECTION ITEMS

INSPECTION REQUIREMENT

NORMAL CONDITION

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-42

PCM TERMINAL RESISTANCE AND CONTINUITY INSPECTION CHART

M1231109400101

INSPECTION PROCEDURE USING AN OSCILLOSCOPE

M1231109500090

Waveform sample

ACX01978

ACX01978AC

TERMINAL NO. INSPECTION ITEM

NORMAL CONDITION (CHECK CONDITION)

57 

− 124

Transmission fluid temperature 
sensor

16.7 

− 20.5 kΩ [at 0 °C (32 °F)]

7.3 

− 8.9 kΩ [at 20 °C (68 °F)]

3.4 

− 4.2 kΩ [at 40 °C (104 °F)]

1.9 

− 2.2 kΩ [at 60 °C (140 °F)]

1.0 

− 1.2 kΩ [at 80 °C (176 °F)]

0.57 

− 0.69 kΩ [at 100 °C (212 °F)]

TERMINAL 
NO.

INSPECTION ITEM

INSPECTION REQUIREMENT

NORMAL CONDITION 
(WAVEFORM SAMPLE)

70

Crankshaft position 
sensor

Transmission 
range: N

Idling (Vehicle 
stopped)

Waveform A

64

Input shaft speed sensor Transmission 

range: Sport 
mode

Driving at constant 
speed of 50 km/h 
(31 mph) in 4th 
gear (Engine: 1,500 
− 2,000 r/min)

Waveform B

73

Output shaft speed 
sensor

79

Vehicle speed sensor

Waveform C

128

Low-reverse solenoid 
valve

• Ignition 

switch: ON

• Transmission 

range: P

• Engine: 

Stopped

• Throttle 

(Accelerator) 
opening 
angle: Less 
than 1 Volt

Force drive each 
solenoid valve 
(Actuator test)

Waveform D

137

Underdrive solenoid 
valve

136

Second solenoid valve

138

Overdrive solenoid valve

129

Reduction solenoid 
valve

130

Torque converter clutch 
control solenoid valve

AC001872AE

WAVEFORM A

(V)

0

5

(ms)

AC001873AD

WAVEFORM B

(V)

0

5

(ms)

AC001873AE

WAVEFORM C

(V)

0

12

(ms)

AC001875AD

WAVEFORM D

(V)

0

20

(ms)

40

60

TRANSFER DIAGNOSIS <ACTIVE TRAC 4WD II>

TSB Revision

AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-43

TRANSFER DIAGNOSIS <ACTIVE TRAC 4WD II>

TRANSFER (ACTIVE TRAC 4WD II) DIAGNOSTIC TROUBLESHOOTING STRATEGY

M1231110800040

Use these steps to plan your diagnostic strategy. If 
you follow them carefully, you will find most transfer 
malfunctions.
1. Gather as much information as possible about the 

complaint from the customer.

2. Verify that the condition described by the 

customer exists.

3. Check the vehicle for any transfer Diagnostic 

Trouble Codes (DTCs).

4. If you can not verify the condition and there are no 

DTCs, the malfunction is intermittent. For 
information on how to cope with intermittent 
malfunctions, refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How 

to Cope with Intermittent Malfunction 

P.00-6

.

5. If there is a DTC, record the number of the code, 

then erase the code from memory using scan tool 
MB991502.

6. If a DTC is set again, go to Inspection Chart for 

Diagnostic Trouble Codes.

7. If a DTC is not set again, the malfunction is 

intermittent. For information on how to cope with 
intermittent malfunctions, refer to GROUP 00, 
How to Use Troubleshooting/Inspection Service 
Points 

− How to Cope with Intermittent 

Malfunction 

P.00-6

.

8. After repairs are completed, confirm the 

malfunction has been eliminated.

TRANSFER DIAGNOSTIC TROUBLE CODE 
DIAGNOSIS

M1231110900047

CHECK CENTER DIFFERENTIAL LOCK 
INDICATOR LIGHT

The center differential lock indicator light flashes once per sec-
ond if there is an abnormality in any of the items below which 
are related to the transfer system. Check for diagnostic trouble 
codes if the center differential lock indicator light is flashing 
once per second. 

ON-BOARD DIAGNOSTICS

The transfer-ECU monitors its input/output signals 
(some signals all the time and others under specified 
conditions). When an irregular signal is initially moni-
tored, the transfer-ECU decides that a malfunction 
has occurred and records the occurrence as a diag-
nostic trouble code. There are 21 diagnostic items. 
The diagnostic results can be read with a scan tool. 
Diagnostic trouble codes are kept in memory by 
direct battery feed. The codes are retained in mem-
ory even if the ignition switch is in the "LOCK" (OFF) 

position. Diagnostic trouble codes will, however, be 
erased when a battery terminal or the transfer-ECU 
connector is disconnected. In addition, the diagnostic 
trouble code can also be erased by scan tool MUT-II 
(MB991502).
NOTE: If a sensor is disconnected when the ignition 
switch is in the "ON" position a diagnostic trouble 
code is stored in memory. In this case, erase the 
DTC using scan tool MB991502.
The 21 diagnostic items are displayed in numeric 
order.

AC204846AB

TRANSFER DIAGNOSIS <ACTIVE TRAC 4WD II>

TSB Revision

AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-44

HOW TO READ AND ERASE DIAGNOSTIC 
TROUBLE CODES

.

<When using the scan tool>

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

CAUTION

To prevent damage to scan tool MB991502, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
NOTE: If the battery positive voltage is low, diagnostic trouble 
codes will not be output. Check the battery if the scan tool 
MB991502 can not display.
NOTE: If the battery is disconnected or if the transfer-ECU con-
nector is disconnected, the diagnostic trouble codes will be 
erased. Do not disconnect the battery or transfer-ECU before 
the diagnostic trouble codes have been read.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Record the diagnostic trouble codes (DTCs) for transfer.
4. Refer to 

P.23Ab-47

, Diagnostic Trouble Code Chart.

5. Turn the ignition switch to the "LOCK" (OFF) and then back 

to "ON" again.

6. Erase the diagnostic trouble code by selecting DTC erase 

from SPECIAL MENU screen, using scan tool MB991502.

7. Check for diagnostic trouble codes. Confirm the scan tool 

displays "normal."

8. Turn the ignition switch to the "LOCK" (OFF) position.
9. Disconnect scan tool MB991502.

.

<When using the differential lock indicator light>

Required Special Tool:

• MB991529: Diagnostic Trouble Code Check Harness

1. Use special tool MB991529 to ground terminal number 1 of 

the data link connector.

2. Turn on the ignition switch to the "ON" position.

ACX01539AD

MB991502

16-PIN

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

ACX01772AD

MB991529