Nissan Pathfinder (2008 year). Manual — part 452

HAC-160

< COMPONENT DIAGNOSIS >

[MANUAL AIR CONDITIONER]

POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER

Is the inspection result normal?

YES

>> System OK.

NO

>> Replace front air control. Refer to XX-XX, "*****".

Front Air Control Power and Ground Diagnosis Procedure

INFOID:0000000001366826

DIAGNOSTIC PROCEDURE FOR A/C SYSTEM

SYMPTOM: A/C system does not come on.

1.

CHECK POWER SUPPLY CIRCUITS FOR FRONT AIR CONTROL

1.

Turn ignition switch OFF.

2.

Disconnect front air control connector.

3.

Turn ignition switch ON.

4.

Check voltage between front air control harness connector M49
terminals 6 and 19, and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>>

Check 10A fuses [Nos. 8 and 19, located in the fuse block (J/B)]. Refer to XX-XX, "*****".

• If fuses are OK, check harness for open circuit. Repair or replace as necessary.
• If fuses are NG, replace fuse and check harness for short circuit. Repair or replace as neces-

sary.

2.

CHECK GROUND CIRCUIT FOR FRONT AIR CONTROL

1.

Turn ignition switch OFF.

2.

Check continuity between front air control harness connector
M49 terminal 20 and ground.

Is the inspection result normal?

YES

>> Replace front air control. Refer to XX-XX, "*****".

NO

>> Repair harness or connector.

WJIA1461E

Terminals

Ignition switch position

(+)

(-)

OFF

ACC

ON

Front air

control

connector

Terminal No.

M49

6

Ground

Approx. 0V

Approx. 0V

Battery
voltage

M49

19

Battery
voltage

Battery
voltage

Battery
voltage

WJIA1082E

20 - Ground

: Continuity should exist.

WJIA1239E

AIR CONDITIONER CONTROL

HAC-161

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

ECU DIAGNOSIS

AIR CONDITIONER CONTROL

System Description

INFOID:0000000001381668

The front air control provides regulation of the vehicle's interior temperature. The system is based on the posi-
tion of the front air controls temperature switch selected by the driver. This is done by utilizing a microcom-
puter, also referred to as the front air control, which receives input signals from the following two sensors:
• Intake sensor
• PBR (position balanced resistor)
The front air control uses these signals (including the set position of the temperature switch) to control:
• Outlet air volume
• Air temperature
• Air distribution

System Operation

INFOID:0000000001381717

AIR MIX DOOR CONTROL

The air mix door is controlled so that in-vehicle temperature changed based on the position of the temperature
control dial.

BLOWER SPEED CONTROL

Blower speed is controlled based on front blower switch settings.
When blower switch is turned, the blower motor starts and increases air flow volume each time the blower
switch is turned counterclockwise, and decreases air flow volume each time the blower switch is turned coun-
terclockwise.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.

INTAKE DOORS CONTROL

The intake doors are controlled by the recirculation switch setting, and the mode (defroster) switch setting.

MODE DOOR CONTROL

The mode door is controlled by the position of the mode dial.

DEFROSTER DOOR CONTROL

The defroster door is controlled by the defroster dial set to defroster.

MAGNET CLUTCH CONTROL

When the A/C switch is pressed, or the mode dial is turned to the defroster position, the front air control out-
puts a compressor ON signal to BCM.
The BCM then sends a compressor ON signal to ECM, via CAN communication line.

WJIA1293E

HAC-162

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

AIR CONDITIONER CONTROL

ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sen-
sor signal, throttle angle sensor, etc.). If it judges compressor can be turned ON, it sends compressor ON sig-
nal to IPDM E/R, via CAN communication line.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.

Front Air Control Terminals Reference Values

INFOID:0000000001366779

Measure voltage between each terminal and ground by following
Terminals and Reference Values for front air control.

FRONT AIR CONTROL HARNESS CONNECTOR TERMINAL LAYOUT

TERMINALS AND REFERENCE VALUES FOR FRONT AIR CONTROL

WJIA1302E

WJIA2011E

Terminal

No.

Wire

color

Item

Ignition

switch

Condition

Voltage (V)

(Approx.)

1

BR

Mode door motor CW

ON

Clockwise rotation

Battery voltage

2

W

Air mix door motor (Driver) CW

ON

Clockwise rotation

Battery voltage

3

GR

Air mix door motor (Driver) CCW

ON

Counterclockwise rotation

Battery voltage

4

Y

Intake door motor CW

ON

Clockwise rotation

Battery voltage

5

O

Intake door motor CCW

ON

Counterclockwise rotation

Battery voltage

6

W/G

Power supply for IGN

ON

-

Battery voltage

8

G

Illumination +

ON

Park lamps ON

Battery voltage

9

BR

Illumination -

-

Park lamps ON

10

W

Compressor ON signal

ON

A/C switch OFF

5V

ON

A/C switch ON

0V

11

Y

Rear defrost request

ON

-

Battery voltage

12

L

Intake sensor

ON

-

0 - 5V

13

V

Sensor ground

ON

-

0 - 5V

14

R

Mode door motor CCW

ON

Counterclockwise rotation

Battery voltage

PIIA2344E

AIR CONDITIONER CONTROL

HAC-163

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

18

BR

Front blower monitor

ON

Front blower motor OFF

Battery voltage

Front blower motor ON

0V

19

R/Y

Power supply for BAT

-

-

Battery voltage

20

B

Ground

-

-

0V

21

V

Mode door motor feedback

ON

-

0 - 5V

22

SB

Air mix door motor (Front) feedback

ON

-

0 - 5V

23

G

Power supply for mode door motor
and air mix door motor (Front) PBR

ON

-

5V

25

R

Rear defroster request

ON

-

Battery voltage

26

P

Ground for mode door motor and air
mix door motor (Front) PBR

ON

-

0V

Terminal

No.

Wire

color

Item

Ignition

switch

Condition

Voltage (V)

(Approx.)

HAC-164

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

AIR CONDITIONER CONTROL

Wiring Diagram

INFOID:0000000001366780

ALIWA0025GB

AIR CONDITIONER CONTROL

HAC-165

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

ALIIA0072GB

HAC-166

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

AIR CONDITIONER CONTROL

ALIIA0073GB

AIR CONDITIONER CONTROL

HAC-167

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

ALIIA0074GB