Mitsubishi Montero (2004+). Manual — part 593

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-15

STEP 2. Check the front blower relay continuity.

Follow the table below to check the front blower relay for conti-
nuity.

Q: Is there continuity at the front blower relay?

YES : Go to Step 3.
NO : Replace the front blower relay. Then go to Step 4.

STEP 3. Check the blower switch continuity.

Follow the table below to check the blower switch for continuity.

Q: Is there continuity at the blower switch?

YES : Go to Step 4.
NO : Replace the blower switch. Then go to Step 4.

STEP 4. Retest the system.
Q: Does the blower motor stop operating?

YES : The procedure complete (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-6

).

NO : Go to Step 1.

BATTERY VOLTAGE

TESTER
CONNECTION

SPECIFIED
CONDITION

Not applied

2

− 5

Open circuit

• Connect terminal 3

to the positive
battery terminal

• Connect terminal 1

to the negative
battery terminal

2

− 5

Less than 2 ohms

AC204714AB

FRONT BLOWER RELAY

SWITCH
POSITION

TESTER
CONNECTION

SPECIFIED
CONDITION

0 (OFF)

1

− 3, 3 − 4, 3 − 5, 3 − 6 Open circuit

1 (LO)

3

− 5

Less than 2 ohms

2 (ML)

1

− 3

Less than 2 ohms

3 (MH)

3

− 6

Less than 2 ohms

4 (HI)

3

− 4

Less than 2 ohms

AC001371

BLOWER SWITCH
ASSEMBLY

AB

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-16

INSPECTION PROCEDURE 6: When the A/C is Operating Condenser Fan does not turn.

DIAGNOSIS

STEP 1. Check the condenser fan control relay continuity.

Follow the table below to check the condenser fan control relay
for continuity.

Q: Is there continuity at the fan control relay?

YES : Go to Step 2.
NO : Replace the condenser fan control relay. Then go to

Step 4.

STEP 2. Check the condenser fan motor operation.

Follow the table below to check the condenser fan motor for
continuity.

Q: Is the condenser fan motor operating correctly?

YES : Go to Step 3.
NO : Replace the condenser fan motor. Then go to Step 3.

STEP 3. Measure the PCM terminal voltage.

Refer to GROUP 13A, Check at PCM terminals

P.13A-968

.

Q: Is the PCM voltage correct?

YES : Go to Step 4.
NO : Replace the PCM. Then go to Step 4.

BATTERY VOLTAGE

TESTER
CONNECTION

SPECIFIED
CONDITION

Not applied

4

− 5

Open circuit

• Connect terminal 3

to the positive
battery terminal

• Connect terminal 1

to the negative
battery terminal

4

− 5

Less than 2 ohms

AC204715

3

1

4

5

AF

BATTERY

CONDENSER
FAN CONTROL
RELAY

CONNECT
POSITIVE BATTERY
TERMINAL TO

CONNECT
NEGATIVE BATTERY
TERMINAL TO

MOTOR
OPERATION

1

2

Rotates

ACX00845 AC

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-17

STEP 4. Retest the system.
NOTE: The condenser fan might not operate when there is an
air conditioning low load from the air conditioning condenser
control, so remove the negative battery terminal and then
check the symptoms after 5 minutes since initial start control
after reconnection.
Q: Is the condenser fan operating correctly?

YES : The procedure complete (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-6

).

NO : Go to Step 1.

INSPECTION PROCEDURE 7: Inside/Outside Air changeover is not possible.

DIAGNOSIS

STEP 1. Check the outside/inside air selection damper
control motor operation.

CAUTION

Disconnect the battery negative terminal when the damper
is in the inside/outside air position.
Check the outside/inside air selection damper control motor by
the following procedures.

Q: Is the outside/inside air selection damper control motor

operating correctly?
YES : Go to Step 2.
NO : Replace the outside/inside air selection damper

control motor. Then go to Step 4.

LEVER
POSITION

BATTERY
CONNECTION

LEVER
OPERATION

At the inside
air position

• Connect terminal 1

to the positive
battery terminal

• Connect terminal 2

to the negative
battery terminal

The lever moves
from the inside air
position to the
outside air position

At the outside
air position

• Connect terminal 1

to the positive
battery terminal

• Connect terminal 3

to the negative
battery terminal

The lever moves
from the outside air
position to the
inside air position

AC309178AB

OUTSIDE
AIR

INSIDE AIR

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-18

STEP 2. Check the outside/inside air selection switch
continuity.

Follow the table below to check the inside/outside air
changeover switch for continuity.

Q: Is there continuity at the outside/inside air selection

switch?
YES : Go to Step 3.
NO : Replace the outside/inside air selection switch. Then

go to Step 4.

STEP 3. Measure the automatic compressor controller
terminal voltage.

Refer to

P.55A-18

.

Q: Is the automatic compressor controller terminal voltage

correct?
YES : Go to Step 4.
NO : Replace the automatic compressor controller. Then

go to Step 4.

STEP 4. Retest the system.
Q: Do the outside/inside air selection damper control

motor operate?
YES : The procedure complete (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-6

).

NO : Go to Step 1.

INSPECTION AT THE AUTOMATIC COMPRESSOR CONTROLLER TERMINAL

M1552010300613

SWITCH
POSITION

TESTER
CONNECTION

SPECIFIED
CONDITION

Inside air

4

− 5

Open circuit

Outside air

4

− 5

Less than 2 ohms

AC001370

OFF

ON

BLOWER
SWITCH
ASSEMBLY

AB

28

27

23 24

26

25

21 22

1

11

2

12

3

13

4

14

5

15

6

16

7

17

8

18

9

19

10

20

AC101882

TERMINAL
NO.

INSPECTION ITEM

INSPECTION REQUIREMENT

NORMAL CONDITION

1

IG2 power supply

Ignition switch ON

Battery positive voltage

2

Input from air thermo
sensor to controller

Ignition switch and A/C switch: OFF

0 V

Ignition switch and A/C switch: ON

2

− 5 V