Mitsubishi Montero (2004+). Manual — part 662

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-137

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

SPECIAL TOOLS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-138

SPECIAL TOOLS

M1554000600051

TOOL

TOOL NUMBER
AND NAME

SUPERSESSION

APPLICATION

MB991958

A: MB991824
B: MB991827
C: MB991910
D: MB991911
E: MB991914
F: MB991825
G: MB991826

MUT-III sub
assembly

A: Vehicle

communication
interface (V.C.I.)

B: MUT-III USB

cable

C: MUT-III main

harness A
(Vehicles with
CAN
communication
system)

D: MUT-III main

harness B
(Vehicles without
CAN
communication
system)

E: MUT-III main

harness C (for
Daimler Chrysler
models only)

F: MUT-III

measurement
adapter

G: MUT-III trigger

harness

MB991824-KIT
NOTE: G: MB991826
MUT-III trigger
harness is not
necessary when
pushing V.C.I. ENTER
key.

Checking diagnostic trouble
codes

CAUTION

MUT-III main harness B
(MB991911) should be used.
MUT-III main harness A and C
should not be used for this
vehicle.

MB991910

MB991826

MB991958

MB991911

MB991914

MB991824

MB991827

MB991825

DO NOT USE

A

B

C

D

E

F

G

DO NOT USE

ON-VEHICLE SERVICE

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-139

ON-VEHICLE SERVICE

CHARGING

M1552001200049

Use the refrigerant recovery station to charge the refrigerant.

METHOD BY USING REFRIGERANT RECOVERY
AND RECYCLING UNIT

Using the refrigerant recovery and recycling unit, refill the
refrigerant.
NOTE: Refer to the Refrigerant Recovery and Recycling Unit
Instruction Manual for operation of the unit.

DISCHARGING SYSTEM

Use the refrigerant recovery unit to discharge refrigerant gas
from the system.
NOTE: Refer to the Refrigerant Recovery and Recycling Unit
Instruction Manual for operation of the unit.

REFILLING OF OIL IN THE A/C SYSTEM

Too little oil will provide inadequate compressor lubrication and
cause a compressor failure. Too much oil will increase dis-
charge air temperature.
When a compressor is installed at the factory, it contains 140
cm

3

(4.7 floz) of refrigerant oil. While the A/C system is in oper-

ation, the oil is carried through the entire system by the refriger-
ant. Some of this oil will be trapped and retained in various
parts of the system.
When the following system components are changed, it is nec-
essary to add oil to the system to replace the oil being removed
with the component.

Compressor oil: SUN PAG 56

MB991223
A: MB991219
B: MB991220
C: MB991221
D: MB991222
Harness set
A: test harness
B: LED harness
C: LED harness
adaptor
D: Probe

MB991223

Making voltage and resistance
measurement during
troubleshooting
A: Connector pin contact pressure
inspection
B: Power circuit inspection
C: Power circuit inspection
D: Commercial tester connection

TOOL

TOOL NUMBER
AND NAME

SUPERSESSION

APPLICATION

MB991223

A

D

C

B

AD

ON-VEHICLE SERVICE

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-140

Quantity:

• Evaporator: 60 cm

3

(2.0 floz)

• Condenser: 15 cm

3

(0.5 floz)

• Suction hose: 10 cm

3

(0.3 floz)

PERFORMANCE TEST

M1554008800037

1. The vehicles to be tested should be in a place that is not in

direct sunlight.

2. Close the high and low-pressure valve of the gauge

manifold.

3. Connect the charging hose (blue) to the low-pressure valve

and connect the charging hose (red) to the high-pressure
valve of the gauge manifold.

4. Install the quick joint (for low-pressure) to the charging hose

(blue), and connect the quick joint (for high-pressure) to the
charging hose (red).

CAUTION

• To connect the quick joint, press section A firmly

against the service valve until a click is heard.

• When connecting, run your hand along the hose while

pressing to ensure that there are no bends in the hose.

5. Connect the quick joint (for low-pressure) to the

low-pressure service valve and connect the quick joint (for
high-pressure) to the high-pressure service valve.
NOTE: The high-pressure service valve is on A/C pipe and
the low-pressure service valve is on the suction hose.

6. Start the engine.
7. Set the A/C controls as follows:

<Testing the front-A/C>

• A/C switch: A/C − ON position

• Mode selection: FACE position

• Temperature control: MAXIMUM COOLING position

• Air selection: RECIRCULATION position

• Blower switch: FAST position

8. Set the A/C controls as follows:

<Testing the rear-A/C>

• The front A/C should be set as described in step 7.

• A/C switch: A/C-ON position

• Temperature control: MAXIMUM COOLING position

• Blower switch: FAST position

9. Adjust engine speed to 1,500 r/min with A/C clutch engaged.
10.Engine should be warmed up with doors and windows

closed.

AC001388

LOW-PRESSURE
VALVE

HIGH-PRESSURE
VALVE

GAUGE MANIFOLD

CHARGING
HOSE (RED)

A

SLEEVE

CHARGING
HOSE (BLUE)

ADAPTOR
VALVE
(FOR
LOW-PRES-
SURE)

ADAPTOR
VALVE
(FOR HIGH-
PRESSURE)

LOW-
PRESSURE
SERVICE
VALVE

HIGH-
PRESSURE
SERVICE
VALVE

AB