Mitsubishi Montero (2004+). Manual — part 592

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-11

STEP 2. Check the dual pressure switch operation.

(1) Remove the dual pressure switch connector and connect

the high/low pressure side terminals located on the harness
side as shown in the illustration.

(2) Install a gauge manifold to the high-pressure side service

valve of the refrigerant line. (Refer to

P.55A-146

.)

(3) When the high/low pressure sides of the dual pressure

switch are at operation pressure (ON) and there is
continuity between the respective terminals.

Q: When the high/low pressure sides of the dual pressure

switch are at operation pressure (ON), is there
continuity between the respective terminals?
YES : Go to Step 3.
NO : Replace the dual pressure switch. Then go to Step 5.

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 5.

STEP 4. Measure the powertrain control module terminal
voltage.

Refer to GROUP 13A, Diagnosis

− Check at the Powertrain

Control Module (PCM)

P.13A-968

.

Q: Is the voltage correct?

YES : Go to Step 5.
NO : Replace the PCM. Then go to Step 5.

STEP 5. Retest the system.
Q: Does the system produce cool air?

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.

ITEM

OFF to ON

ON to OFF

Low-pressure side
kPa (psi)

223

± 27 (32.4 ±

3.9)

196

± 20 (28.4 ±

2.9)

High-pressure side
kPa (psi)

2,550

± 200 (369.9

± 29)

3,140

± 200

(455.5

± 29)

ACX00822

ON

OFF

196 ± 20
(284 ± 2.9)

223 ± 27
(32.4 ± 3.9)

2,550 ± 200
(369.9 ± 29)

3,140 ± 200
(455.5 ± 29)

kPa
(psi)

DUAL PRESSURE
SWITCH

AF

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-12

INSPECTION PROCEDURE 4: Blower Fan and Motor does not turn.

DIAGNOSIS

STEP 1. Check the front blower relay continuity.

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

Q: Is the front blower relay continuity in good condition?

YES : Go to Step 2.
NO : Replace the front blower relay. Then go to Step 5.

STEP 2. Check the blower motor operation.

When battery voltage is applied between the terminals, check
that the motor operates.
Q: Is there any abnormal noise?

YES : Go to Step 3.
NO : Replace the blower motor. Then go to Step 5.

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

AC001038 AB

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-13

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 5.

STEP 4. Check the blower resistor resistance value.

Use an ohmmeter to measure the resistance between the ter-
minals as indicated below. Check that the measured value is at
the standard value.

Q: Is the measured value at the standard value?

YES : Go to Step 5.
NO : Replace the blower resistor. Then go to Step 5.

STEP 5. Retest the system.
Q: Do the blower fan and 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.

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

MEASUREMENT TERMINAL

STANDARD VALUE

Ω

Between terminals 2 and 3 (LO) 2.79

Between terminals 1 and 2 (ML) 1.49

Between terminals 2 and 4 (MH) 0.36

AC002646

1 2

3 4

AB

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-14

INSPECTION PROCEDURE 5: Blower Fan and Motor does not Stop turning.

DIAGNOSIS

STEP 1. Check the harness wires between the blower
motor connector D-113, the blower resistor connector
D-115, and the blower switch connector D-101.

Q: Are the harness wires between the blower motor

connector D-113, the blower resistor connector D-115,
and the blower switch connector D-101 in good
condition?
YES : Go to Step 2.
NO : Repair the wiring harness. Then go to Step 4.

AC204170

CONNECTOR : D-101

BZ

HARNESS
SIDE

1
4

2

3

5

6

AC204189

CONNECTORS : D-113, D-115

D-113

AB

D-115

D-113

HARNESS SIDE

HARNESS SIDE

D-115

1

2

1

2

3

4