Mitsubishi Montero (2002-2004). Manual — part 109

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-129

STEP 3. Replace the lock sensor.
Q: Does the air conditioning work normally?

YES : No action is necessary and testing is complete.
NO : Replace the A/C-ECU. (Refer to

P.55B-136

.) Check

that the air conditioning works normally.

DATA LIST REFERENCE TABLE

M1554005100051

MUT-II SCAN
TOOL DISPLAY

ITEM
NO.

INSPECTION ITEM INSPECTION REQUIREMENT

NORMAL VALUE

A/M DAMPER

31

Air mixing damper
control motor
potentiometer

Ignition switch: ON Damper

position

Opening degree (%)

MAX. HOT

Approx. 100

MAX. COOL

Approx. 0

OUTSIDE TEMP 13

Outside air
temperature sensor

Ignition switch: ON

Outside air
temperature and
temperature
displayed on the
scan tool are
identical.

EVAP TEMP

21

Air thermo sensor

Ignition switch: ON

The temperature of
the air, which flows
through the
evaporator, and
temperature
displayed on the
scan tool are
identical.

AIR OUT POS

32

Mode selection
damper control
motor potentiometer

Ignition switch: ON Damper

position

Opening degree (%)

FACE

Approx. 0

FOOT

Approx. 50

FOOT/DEF.

Approx. 75

DEF.

Approx. 100

PHOTO SNSR

25

Photo sensor

Ignition switch: ON

Amount of incident
light is proportional
to voltage displayed
on the scan tool.

INSIDE TEMP

11

Inside air
temperature sensor

Ignition switch: ON

Inside air
temperature and
temperature
displayed on the
scan tool are
identical.

HEATER TEMP

15

heater water
temperature sensor

Ignition switch: ON

ON when heater
core wall
temperature is 30

°C

(86

°F) or higher.

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-130

ACTUATOR TEST REFERENCE

M1554005200058

CHECK AT ECU TERMINAL

M1554005400085

MUT-II SCAN TOOL
DISPLAY

ITEM NO.

INSPECTION ITEM

DRIVE CONTENT

A/M 0%

05

Air mix damper motor

Opening degree: approx.
0%

A/M 100%

07

Opening degree: approx.
100%

A/M 50%

06

Opening degree: approx.
50%

CLUTCH OFF

11

A/C compressor

OFF

CLUTCH ON

12

ON

DEF

10

Air outlet changeover damper
motor

DEF

FACE

08

FACE

FAN HI

04

Blower motor

HI

FAN LO

02

LO

FAN ME

03

ME

FAN OFF

01

OFF

FOOT

09

Air outlet changeover damper
motor

FOOT

FRESH

13

Inlet/outlet air changeover damper
motor

FRESH

RECIRC

14

RECIRCULATION

1

2 3 4 5 6

7 8

9 10

11 12 13 14 15 16 17 18 19 20

32 33 34

29

30 31

21 22 23 24 25 26 27 28

35 36

AC002694

TERMINAL
NO.

INSPECTION ITEM

INSPECTION CONDITION

NORMAL
CONDITION

1

Air mixing damper control motor When the air mix damper is moved to

the MAX. COOL position.

10 V

When the air mix damper is moved to
the MAX. HOT position.

0.5 V

2

Mode selection damper control
motor (FACE)

When the damper is moved to the
FACE position.

10 V

When the damper is moved to the
DEF position.

0.5 V

3

Inside/outside air changeover
damper motor (inside air)

When the damper flap is moving to
the inside air recirculation position.

0.5 V

When the damper flap is moving to
the outside air induction position.

10 V (when the
motor is stopped)

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-131

4

Inside/outside air changeover
damper motor (FRESH)

When the damper flap is moving to
the inside air recirculation position.

0 V (when the
motor is stopped)

When the damper flap is moving to
the outside air induction position.

0.5 V

5

Request signal for turning the A/
C compressor on

Dual pressure switch: OFF

System voltage

Dual pressure switch: ON

0 V

6

RV meter communication line

Ignition switch: ON

Hi: 4

− 5 V

Lo: 0

− 1 V

7

PCM communication line

When the A/C is off.

0 V

When the A/C (compressor) is
operating

System voltage

8

-

-

-

9

Lock sensor input

When the compressor is operating

0

− 0.75 V (pulse

signal)

10

Heater blower controller unit
output

When the blower is operating

0

− 3.5 V

(alternative
effective value)

11

Air mixing damper control motor When the air mix damper is moved to

the MAX. COOL position.

0.5 V

When the air mix damper is moved to
the MAX. HOT position.

10 V

12

Air outlet changeover damper
motor (DEF)

When the damper is moved to the
FACE position.

0.5 V

When the damper is moved to the
DEF position.

10 V

13

-

-

-

14

Blower relay

When the blower is stopped

System voltage

When the blower is operating

0 V

15

Rear defogger

Rear defogger: OFF

System voltage

Rear defogger: ON

0 V

16

RV meter communication line

Ignition switch: ON

Hi: 4

− 5 V

Lo: 0

− 1 V

17

RV meter communication line

Ignition switch: ON

Hi: 4

− 5 V

Lo: 0

− 1 V

18

RV meter communication line
shield

At all times

0 V

19

Diagnosis data output

Ignition switch: ON

0

⇔ Battery

positive voltage

20

A/C compressor relay input

When the A/C is off.

0 V

When the A/C (compressor) is
operating

System voltage

21

Potentiometer power supply

At all times

5 V

TERMINAL
NO.

INSPECTION ITEM

INSPECTION CONDITION

NORMAL
CONDITION

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-132

22

Outside air temperature sensor
input

When sensor section temperature is
25

°C (77°F) [4 kΩ]

1.9 V

23

Heater water temperature sensor
input

When sensor section temperature is
25

°C (77°F) [4 kΩ]

2.8 V

24

Air mixing damper control motor
potentiometer input

When the damper door has moved to
the MAX. HOT position.

0.7

− 1.3 V

25

ILL power supply

Lighting switch: ON

System voltage

26

A/C-ECU power supply (IG2)

Ignition switch: ON

System voltage

27

A/C-ECU power supply (ACC)

Ignition switch: ACC

System voltage

28

A/C-ECU power supply (back-
up)

At all times

System voltage

29

Sensors and potentiometers
ground

At all times

0 V

30

Air thermo sensor input

When sensor section temperature is
25

°C (77°F) [1.5 kΩ]

2.2 V

31

Photo sensor (+)

At luminous intensity of 100,000 lux
or more

1 V

32

Mode selection damper control
motor potentiometer input

When the damper has moved to the
DEF position.

0.7

− 1.3 V

33

DTC input

Ignition switch: ON

0 V

34

A/C compressor lock signal
(ignition signal)

Engine speed: 3,000 r/min

0.3

− 3.0 V

35

Illumination ground

At all times

0 V

36

Ground

At all times

0 V

TERMINAL
NO.

INSPECTION ITEM

INSPECTION CONDITION

NORMAL
CONDITION