Mitsubishi Montero (2004+). Manual - part 661

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-133

STEP 2. Check the wiring harness between A/C-ECU
connector D-23 (terminal 9), D-24 (terminal 29) and A/C
compressor connector B-30 (terminal 1, 2).

NOTE: Also check intermediate connector E-111. If intermedi-
ate connector E-111 is damaged, repair or replace the connec-
tor as described in GROUP 00E, Harness Connector
Inspection

P.00E-2

Q: Is the wiring harness between A/C-ECU connector D-23

(terminal 9), D-24 (terminal 29) and A/C compressor
connector B-30 (terminal 1, 2) in good condition?
YES : Go to Step 3.
NO : Repair the wiring harness. Check that the air

conditioning works normally.

AC204169

CONNECTOR : B-30

B-30(B)

HARNESS
SIDE

AC204188

CONNECTORS : D-23, D-24

D-24(B)

D-23(B)

HARNESS SIDE

30 29

3635

1413

10 9

AC204176

CONNECTOR : E-111

26 27

23 24

20 21

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-134

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-142

). Check

that the air conditioning works normally.

DATA LIST REFERENCE TABLE

M1554005100169

MUT-III SCAN
TOOL DISPLAY

ITEM
NO.

INSPECTION ITEM INSPECTION REQUIREMENT

NORMAL VALUE

A/M DAMPER

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 scan
tool are identical.

EVAP TEMP

A/C sensor

Ignition switch: ON

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

AIR OUT POS

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

Photo sensor

Ignition switch: ON

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

INSIDE TEMP

Inside air
temperature sensor

Ignition switch: ON

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

HEATER TEMP

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-135

ACTUATOR TEST REFERENCE

M1554005200155

CHECK AT ECU TERMINAL

M1554005400171

MUT-III SCAN TOOL
DISPLAY

ITEM
NO.

INSPECTION ITEM

DRIVE CONTENT

A/M 0%

Air mix damper motor

Opening degree: approx. 0%

A/M 100%

Opening degree: approx. 100%

A/M 50%

Opening degree: approx. 50%

CLUTCH OFF

A/C compressor

OFF

CLUTCH ON

DEF

Air outlet changeover damper motor DEF

FACE

FAN HI

Blower motor

FAN LO

FAN ME

FAN OFF

OFF

FOOT

Air outlet changeover damper motor FOOT

FRESH

Inlet/outlet air changeover damper
motor

FRESH

RECIRC

RECIRCULATION

2 3 4 5 6

7 8

9 10

11 12 13 14 15 16 17 18 19 20

32 33 34

30 31

21 22 23 24 25 26 27 28

35 36

AC002694

TERMINAL
NO.

INSPECTION ITEM

INSPECTION CONDITION

NORMAL
CONDITION

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

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

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)

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

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-136

Request signal for turning the
A/C compressor on

Dual pressure switch: OFF

System voltage

Dual pressure switch: ON

0 V

RV meter communication line

Ignition switch: ON

Hi: 4

− 5 V

Lo: 0

− 1 V

PCM communication line

When the A/C is off.

0 V

When the A/C (compressor) is operating System voltage

Lock sensor input

When the compressor is operating

− 0.75 V (pulse

signal)

Heater blower controller unit
output

When the blower is operating

− 3.5 V

(alternative
effective value)

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

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

Blower relay

When the blower is stopped

System voltage

When the blower is operating

0 V

Rear defogger

Rear defogger: OFF

System voltage

Rear defogger: ON

0 V

RV meter communication line

Ignition switch: ON

Hi: 4

− 5 V

Lo: 0

− 1 V

RV meter communication line

Ignition switch: ON

Hi: 4

− 5 V

Lo: 0

− 1 V

RV meter communication line
shield

At all times

0 V

Diagnosis code set

Ignition switch: ON

⇔ Battery

positive voltage

A/C compressor relay input

When the A/C is off.

0 V

When the A/C (compressor) is operating System voltage

Potentiometer power supply

At all times

5 V

Outside air temperature sensor
input

When sensor section temperature is
25

°C (77°F) [4 kΩ]

1.9 V

Heater water temperature
sensor input

When sensor section temperature is
25

°C (77°F) [4 kΩ]

2.8 V

Air mixing damper control
motor potentiometer input

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

0.7

− 1.3 V

ILL power supply

Lighting switch: ON

System voltage

TERMINAL
NO.

INSPECTION ITEM

INSPECTION CONDITION

NORMAL
CONDITION

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