Nissan Pathfinder (2009 year). Manual - part 471

POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER

HAC-163

< COMPONENT DIAGNOSIS >

[MANUAL AIR CONDITIONER]

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POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER

Component Description

INFOID:0000000003935979

COMPONENT DESCRIPTION

Front Air Control

The front air control (1) has a built-in microcomputer which pro-
cesses information sent from various sensors needed for air condi-
tioner operation. The air mix door motor, mode door motor, intake
door motor, defroster door motor, blower motor and compressor are
then controlled.
The front air control is unitized with control mechanisms. When the
various switches and temperature dials are operated, data is input to
the front air control. 

Potentio Temperature Control (PTC)

The PTC is built into the front air control. It can be set from cold to
hot or any intermediate position by rotating the temperature dial.

Front Air Control Component Function Check

INFOID:0000000003935980

SYMPTOM: A/C system does not come on.

INSPECTION FLOW

1.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK

1.

Turn blower control dial to position 1-4, then press A/C switch.

2.

Confirm that the compressor clutch engages (sound or visual inspection). 

Can a symptom be duplicated?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

PERFORM COMPLETE OPERATIONAL CHECK

Perform a complete operational check and check for any symptoms. Refer to 

HAC-125, "Operational Check"

.

Can a symptom be duplicated?

YES

>> Refer to 

HAC-174, "Symptom Matrix Chart"

.

NO

>> System OK.

3.

CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 4.

4.

CHECK POWER AND GROUND CIRCUIT

Check main power supply and ground circuit. Refer to 

HAC-164, "Front Air Control Power and Ground Diag-

nosis Procedure"

.

AWIIA1197ZZ

WJIA1311E

2009 Pathfinder

HAC-164

< 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 

VTL-7, "Removal and Installation"

.

Front Air Control Power and Ground Diagnosis Procedure

INFOID:0000000003935981

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 M52
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 

PG-72, "Terminal

Arrangement"

.

• 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
M52 terminal 20 and ground.

Is the inspection result normal?

YES

>> Replace front air control. Refer to 

VTL-7, "Removal and

Installation"

.

NO

>> Repair harness or connector.

WJIA1461E

Terminals

Ignition switch position

(+)

(-)

OFF

ACC

ON

Front air 

control 

connector

Terminal No.

M52

6 

Ground

Approx. 0V

Approx. 0V

Battery 
voltage

M52

19 

Battery 
voltage

Battery 
voltage

Battery 
voltage

AWIIA0863ZZ

20 - Ground

: Continuity should exist.

AWIIA0864ZZ

2009 Pathfinder

AIR CONDITIONER CONTROL

HAC-165

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

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ECU DIAGNOSIS

AIR CONDITIONER CONTROL

System Description 

INFOID:0000000003935982

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:0000000003935983

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

2009 Pathfinder

HAC-166

< 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:0000000003935984

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 

AWIIA1197ZZ

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

2009 Pathfinder

AIR CONDITIONER CONTROL

HAC-167

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

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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.)

2009 Pathfinder

HAC-168

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

AIR CONDITIONER CONTROL

Wiring Diagram

INFOID:0000000003935985

ABIWA0020GB

2009 Pathfinder

AIR CONDITIONER CONTROL

HAC-169

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

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ABIIA0102GB

2009 Pathfinder

HAC-170

< ECU DIAGNOSIS >

[MANUAL AIR CONDITIONER]

AIR CONDITIONER CONTROL

ABIIA0103GB

2009 Pathfinder