Nissan Pathfinder (2008 year). Manual - part 442

HAC-80

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

IN-VEHICLE SENSOR

IN-VEHICLE SENSOR

Component Description

INFOID:0000000001366735

COMPONENT DESCRIPTION

In-vehicle Sensor

The in-vehicle sensor (1) is located on the lower instrument panel
LH. It converts variations in temperature of passenger compartment
air (drawn in through the integrated fan) into a resistance value. It is
then input into the A/C auto amp.

In-Vehicle Sensor Diagnosis Procedure

INFOID:0000000001366736

DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR

SYMPTOM: In-vehicle sensor circuit is open or shorted. Using the
CONSULT-III, DTC B2578 or B2579 is displayed. Without a CON-
SULT-III, code 30, 31, 44 or 46 is indicated on A/C auto amp. as a
result of conducting self-diagnosis.

1.

CHECK IN-VEHICLE SENSOR CIRCUIT

Is self-diagnosis DTC B2578 or B2579 (with CONSULT-III) or code 30, 31 44 or 46 (without CONSULT-III)
present?

YES or NO?

YES

>> GO TO 6.

NO

>> GO TO 2.

2.

CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND

AWIIA0264ZZ

AWIIA0265ZZ

AWIIA0166GB

IN-VEHICLE SENSOR

HAC-81

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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1.

Disconnect in-vehicle sensor connector.

2.

Turn ignition switch ON.

3.

Check voltage between in-vehicle sensor harness connector
M32 terminal 1 and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 5.

3.

CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND A/C AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector M49.

3.

Check continuity between in-vehicle sensor harness connector
M32 (B) terminal 1 and A/C auto amp. harness connector M50
(A) terminal 32.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair harness or connector.

4.

CHECK IN-VEHICLE SENSOR

Check in-vehicle sensor. Refer to 

HAC-82, "In-Vehicle Sensor Component Inspection"

.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-8, "Removal and Installation"

.

2.

Go to 

HAC-23, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> 1.

Replace in-vehicle sensor. Refer to 

VTL-10, "Removal and Installation"

.

2.

Go to 

HAC-23, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

5.

CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND A/C AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector.

3.

Check continuity between in-vehicle sensor harness connector
M32 (B) terminal 4 and A/C auto amp. harness connector M49
(A) terminal 26.

4.

Check continuity between in-vehicle sensor harness connector
M32 (B) terminal 4 and ground.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-8, "Removal and Installation"

.

2.

Go to 

HAC-23, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> Repair harness or connector.

6.

CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR MOTOR AND A/C AUTO AMP. (SELF-

DIAGNOSIS CODES 30, 31, 44, 46 OR DTC B2578, B2579)

1 - Ground

: Approx. 5V.

AWIIA0266ZZ

1 - 32

: Continuity should exist.

AWIIA0267ZZ

4 - 26

: Continuity should exist.

4 - Ground

Continuity should not exist.

AWIIA0268ZZ

HAC-82

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

IN-VEHICLE SENSOR

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector and in-vehicle sensor con-
nector.

3.

Check continuity between in-vehicle sensor harness connector
M32 (B) terminal 3 and A/C auto amp. harness connector M50
(A) terminal 31. 

4.

Check continuity between in-vehicle sensor harness connector
M32 (B) terminal 3 and ground.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-8, "Removal and Installation"

.

2.

Go to 

HAC-23, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> Repair harness or connector.

In-Vehicle Sensor Component Inspection

INFOID:0000000001366737

COMPONENT INSPECTION

In-vehicle Sensor

After disconnecting in-vehicle sensor connector M32, measure resis-
tance between terminals 1 and 4 at sensor component side, using
the table below.

If NG, replace in-vehicle sensor. Refer to 

VTL-10, "Removal and

Installation"

.

3 - 31

: Continuity should exist.

2 - Ground

: Continuity should exist.

3 - Ground

: Continuity should not exist.

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Temperature 

°

C (

°

F)

Resistance k

Ω

−

15 (5)

21.40

−

10 (14)

16.15

−

5 (23)

12.29

0 (32)

9.41

5 (41)

7.27

10 (50)

5.66

15 (59)

4.45

20 (68)

3.51

25 (77)

2.79

30 (86)

2.24

35 (95)

1.80

40 (104)

1.45

45 (113)

1.18

AWIIA0269ZZ

OPTICAL SENSOR

HAC-83

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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OPTICAL SENSOR

Component Description

INFOID:0000000001366738

COMPONENT DESCRIPTION

The optical sensor is located in the center of the defroster grille. It
detects sunload entering through windshield by means of a photo
diode. The sensor converts the sunload into a current value which is
then input into the A/C auto amp.

OPTICAL INPUT PROCESS

The A/C auto amp. includes a processing circuit which averages the variations in detected sunload over a
period of time. This prevents adjustments in the ATC system operation due to small or quick variations in
detected sunload.
For example, consider driving along a road bordered by an occasional group of large trees. The sunload
detected by the optical sensor will vary whenever the trees obstruct the sunlight. The processing circuit aver-
ages the detected sunload over a period of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in the ATC system operation. On the other hand, shortly
after entering a long tunnel, the system will recognize the change in sunload, and the system will react accord-
ingly.

Optical Sensor Diagnosis Procedure

INFOID:0000000001366739

DIAGNOSTIC PROCEDURE FOR OPTICAL SENSOR

SYMPTOM: Optical sensor circuit is open or shorted. Using the
CONSULT-III, DTC B257F or B2580 is displayed. Without a CON-
SULT-III, code 50 or 52 is indicated on A/C auto amp. as a result of
conducting self-diagnosis.

1.

CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND A/C AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector and optical sensor connec-
tor.

3.

Check continuity between optical sensor harness connector
M145 (B) terminals 1 and 2 and A/C auto amp. harness connec-
tor M50 (C) terminal 42 and M49 (A) terminal 1.

4.

Check continuity between optical sensor harness connector
M145 terminal 1 and 2 and ground.

AWIIA0169ZZ

AWIIA0205GB

1 - 1

: Continuity should exist.

2 - 42

: Continuity should exist.

AWIIA0206ZZ

HAC-84

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

OPTICAL SENSOR

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair harness or connector.

2.

CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND BCM

1.

Disconnect BCM connector.

2.

Check continuity between optical sensor harness connector
M145 (B) terminal 3 and 4 and BCM harness connector M18 (A)
terminal 18 and M20 (C) terminal 58.

3.

Check continuity between optical sensor harness connector
M145 (A) terminal 4 and ground.

Is the inspection result normal?

YES

>> Replace optical sensor. Refer to 

VTL-11, "Removal and Installation"

.

NO

>> Repair harness or connector.

1, 2 - Ground.

: Continuity should not exist.

3 - 18

: Continuity should exist.

4 - 58

: Continuity should exist.

3, 4 - Ground

: Continuity should not exist.

AWIIA0270ZZ

INTAKE SENSOR

HAC-85

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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INTAKE SENSOR

System Description

INFOID:0000000001366740

COMPONENT DESCRIPTION

Intake Sensor

The intake sensor is located on the heater & cooling unit assembly. It
converts temperature of air after if passes through the evaporator
into a resistance value which is then input to the A/C auto amp.

Intake Sensor Diagnosis Procedure

INFOID:0000000001366741

DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR

SYMPTOM: Intake sensor circuit is open or shorted. Using the CON-
SULT-III, DTC B2581 or B2582 is displayed. Without a CONSULT-III,
code 56 or 57 is indicated on A/C auto amp. as a result of conducting
self-diagnosis.

1.

CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND

1.

Disconnect intake sensor connector.

2.

Turn ignition switch ON.

3.

Check voltage between intake sensor harness connector M146
terminal 2 and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 4.

2.

CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND A/C AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector.

3.

Check continuity between intake sensor harness connector
M146 (B) terminal 1 and A/C auto amp. harness connector M49
(A) terminal 21.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair harness or connector.

WJIA1155E

AWIIA0208GB

2 - Ground

: Approx. 5V

WJIA1375E

1 - 26

: Continuity should exist.

AWIIA0209ZZ

HAC-86

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

INTAKE SENSOR

3.

CHECK INTAKE SENSOR

Check intake sensor. Refer to 

HAC-86, "Intake Sensor Component Inspection"

.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-8, "Removal and Installation"

.

2.

Go to 

HAC-23, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> 1.

Replace intake sensor. Refer to XXXX.

2.

Go to 

HAC-23, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

4.

CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND A/C AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector.

3.

Check continuity between intake sensor harness connector
M146 (B) terminal 2 and A/C auto amp. harness connector M49
(A) terminal 11.

4.

Check continuity between intake sensor harness connector
M146 terminal 2 and ground.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-8, "Removal and Installation"

.

2.

Go to 

HAC-23, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> Repair harness or connector.

Intake Sensor Component Inspection

INFOID:0000000001366742

COMPONENT INSPECTION

Intake Sensor

After disconnecting intake sensor connector, measure resistance
between terminals 1 and 2 at sensor harness side, using the table
below.

If NG, replace intake sensor. Refer to 

VTL-12, "Removal and Installa-

tion"

.

2 - 11

: Continuity should exist.

2 - Ground

: Continuity should not exist.

AWIIA0216ZZ

Temperature 

°

C (

°

F)

Resistance k

Ω

−

15 (5)

209.0

−

10 (14)

160.0

−

5 (23)

123.0

0 (32)

95.8

5 (41)

74.9

10 (50)

58.9

15 (59)

46.7

20 (68)

37.3

25 (77)

30.0

30 (86)

24.2

35 (95)

19.7

40 (104)

16.1

45 (113)

13.2

WJIA1159E

POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER

HAC-87

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER

Component Description

INFOID:0000000001366743

COMPONENT DESCRIPTION

A/C auto amp.

The A/C auto amp. (1) has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motors, mode door motor, intake door
motor, defroster door motor, blower motor and compressor are then
controlled.
The A/C auto amp. is unitized with control mechanisms. When the
various switches and temperature dials are operated, data is input to
the A/C auto amp. 
Self-diagnostic functions are also built into the A/C auto amp. to pro-
vide quick check of malfunctions in the auto air conditioner system.

Potentio Temperature Control (PTC)

There are two PTCs (driver and passenger) built into the A/C auto
amp. They can be set at an interval of 0.5

°

C (1.0

°

F) in the 18

°

C

(60

°

F) to 32

°

C (90

°

F) temperature range by rotating the temperature

dial. The set temperature is displayed.

A/C Auto Amp. Component Function Check

INFOID:0000000001366744

SYMPTOM: A/C system does not come on.

INSPECTION FLOW

1.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - AUTO MODE

1.

Press AUTO switch.

2.

Display should indicate AUTO. Confirm that the compressor clutch engages (sound or visual inspection).
(Discharge air and blower speed will depend on ambient, in-vehicle and set temperatures.) 

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-123, "Operational Check"

.

Can a symptom be duplicated?

YES

>> Refer to 

HAC-122, "How to Perform Trouble Diagnosis For Quick And Accurate Repair"

.

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-160, "Front Air Control Power and Ground Diag-

nosis Procedure"

.

AWIIA0170ZZ

AWIIA0211GB