Mitsubishi Montero (2004+). Manual — part 629

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-5

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. Ensure that the ignition switch is at the "LOCK" (OFF)

position.

2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824

and the personal computer.

4. Connect special tool MB991911 to special tool MB991824
5. Connect special tool MB991911 to the data link connector.
6. Turn the power switch of special tool MB991824 to the "ON"

position.
NOTE: When the special tool MB991824 is energized, the
special tool MB991824 indicator light will be illuminated in a
green color.

7. Start the MUT-III system on the personal computer.
NOTE: Disconnecting scan tool special tool MB991958 is the
reverse of the connecting sequence, making sure that the igni-
tion switch is at the "LOCK" (OFF) position.

HOW TO READ AND ERASE DIAGNOSTIC
TROUBLE CODES

Required Special Tool:

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

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B (Vehicles without

CAN communication system)

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.
NOTE: If the battery voltage is low, diagnostic trouble codes will
not be set. Check the battery if scan tool MB991958 does not
display.
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 "AUTO A/C" from the "BODY" tab.
6. Select "MITSUBISHI."
7. Select "Diagnostic Trouble Code."
8. If a DTC is set, it is shown.
9. Choose "Erase DTC" to erase the DTC.

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-6

HOW TO READ DATA LIST

Required Special Tool:

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

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B (Vehicles without

CAN communication system)

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 "AUTO A/C" from the "BODY" tab.
6. Select "MITSUBISHI."
7. Select "Data List."
8. Choose an appropriate item and select the "OK" button.

HOW TO PERFORM ACTUATOR TEST

Required Special Tool:

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

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B (Vehicles without

CAN communication system)

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-7

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 "AUTO A/C" from the "BODY" tab.
6. Select "MITSUBISHI."
7. Choose "Actuator Test" from "AUTO A/C" screen.
8. Choose an appropriate item and select the "OK" button.

DIAGNOSTIC TROUBLE CODE CHART

M1554004900043

SYMPTOM CHART

M1554005000225

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827

DIAGNOSTIC
TROUBLE CODE NO.

DIAGNOSTIC ITEM

REFERENCE
PAGE

Inside air temperature sensor system (open circuit)

P.55B-8

Inside air temperature sensor system (short circuit)

P.55B-8

Outside air temperature sensor system (open circuit)

P.55B-9

Outside air temperature sensor system (short circuit)

P.55B-9

Heater water temperature sensor system (open circuit)

P.55B-13

Heater water temperature sensor system (short circuit)

P.55B-13

Air thermo sensor system (open circuit)

P.55B-17

Air thermo sensor system (short circuit)

P.55B-17

Potentiometer system of air mixing damper control motor assembly

P.55B-20

Potentiometer system of air outlet changeover damper control
motor assembly

P.55B-24

SYMPTOM

INSPECTION
PROCEDURE NO.

REFERENCE
PAGE

Communication with scan tool is not possible.

P.55B-28

Air conditioning does not operate.

P.55B-34

A/C outlet air temperature cannot be set.

P.55B-54

Blower does not operate.

P.55B-63

Blower air amount cannot be changed.

P.55B-80

Air outlets cannot be changed.

P.55B-84

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-8

DIAGNOSTIC TROUBLE CODE PROCEDURES

DTC 11, 12: Inside Air Temperature Sensor System

DTC SET CONDITION
DTC 11 or 12 is displayed when the A/C-ECU
detects an error is its own data. This fault is limited to
the A/C-ECU.

TROUBLESHOOTING HINT

• Malfunction of the A/C-ECU.

• Malfunction of the flexible flat cable.

• Malfunction of the A/C control panel.

DIAGNOSIS

Required Special Tools:

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

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B (Vehicles without

CAN communication system)

STEP 1. Using scan tool MB991958, check data list item 11:
Inside air temperature sensor.

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.
Item 11: Inside air temperature sensor
OK: The inside air temperature and indicated temperature on
scan tool MB991958 are almost equal.
Q: Are the inside air temperature and temperature

displayed on scan tool MB991958 almost equal?
YES : It can be assumed that this malfunction is intermittent

(Refer to GROUP 00

− How to Cope with Intermittent

Malfunction

P.00-6

NO : Go to Step 2.

Inside/outside air changeover is not possible.

P.55B-89

Rear defogger does not operate.

P.55B-96

Condenser fan does not operate.

P.55B-110