Nissan Pathfinder (2009 year). Manual - part 460

HEATER PUMP

HAC-75

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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HEATER PUMP

System Description (VQ40DE)

INFOID:0000000003935917

SYSTEM DESCRIPTION

Component Parts

Heater pump control system components are:
• A/C auto amp.
• Heater pump relay
• Heater pump
• Intake sensor

System Operation

The heater pump improves heater performance specifically at idle conditions. It is designed to operate in
either of the following 2 situations:
1.

Front blower motor set to maximum speed and temperature control dial (driver or passenger) set to full hot
32

°

C (90

°

F) or

2.

Engine coolant temperature (signal via CAN communication) minus heater core outlet temperature (intake
sensor input to A/C auto amp.) is greater than 20

°

C (68

°

F). If the difference is less than 16

°

C (61

°

F), the

heater pump will not operate unless the conditions in item No. 1 above are met.

Diagnosis Procedure (VQ40DE)

INFOID:0000000003935918

DIAGNOSTIC PROCEDURE FOR HEATER PUMP CIRCUIT

1.

CHECK POWER SUPPLY TO HEATER PUMP

1.

Disconnect heater pump connector.

2.

Turn ignition switch ON.

3.

Set front blower motor to maximum speed.

4.

Turn temperature control dial (passenger or driver) to full hot 32

°

C (90

°

F).

5.

Check voltage between heater pump harness connector E141
terminal 1 and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> GO TO 3.

WJIA1780E

1 - Ground

: Battery voltage

WJIA1984E

2009 Pathfinder

HAC-76

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

HEATER PUMP

2.

CHECK HEATER PUMP GROUND

1.

Turn ignition switch OFF.

2.

Check continuity between heater pump harness connector E141
terminal 2 and ground.

Is the inspection result normal?

YES

>> Replace heater pump. Refer to 

HA-58, "Removal and

Installation"

.

NO

>> Repair harness or connector.

3.

CHECK HEATER PUMP RELAY

1.

Turn ignition switch OFF.

2.

Check heater pump relay. Refer to 

HAC-77, "Component Inspection (VQ40DE)"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace heater pump relay.

4.

CHECK RELAY POWER SUPPLY

1.

Turn ignition switch ON.

2.

Check voltage between heater pump relay harness connector
E144 terminals 2, 5 and ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair harness or connector.

5.

CHECK HEATER PUMP MOTOR POWER CIRCUIT

1.

Turn ignition switch OFF.

2.

Check continuity between heater pump relay harness connector
(A) E144 terminal 3 and heater pump harness connector (B)
E141 terminal 1.

3.

Check continuity between heater pump relay harness connector
(A) E144 terminal 3 and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Repair harness or connector.

6.

CHECK CIRCUIT BETWEEN HEATER PUMP RELAY AND A/C AUTO AMP.

2 - Ground

: Continuity should exist.

WJIA1985E

2 - Ground

: Battery voltage

5 - Ground

: Battery voltage

WJIA1986E

3 - 1

: Continuity should exist.

3 - Ground

: Continuity should not exist.

WJIA1987E

2009 Pathfinder

HEATER PUMP

HAC-77

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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1.

Disconnect A/C auto amp. connector.

2.

Check continuity between A/C auto amp. harness connector
M50 (A) terminal 50 and heater pump relay harness connector
E144 (B) terminal 1.

3.

Check continuity between heater pump relay harness connector
E144 (B) terminal 1 and ground.

Is the inspection result normal?

YES

>> Replace A/C auto amp. Refer to 

VTL-7, "Removal and Installation"

.

NO

>> Repair harness or connector.

Component Inspection (VQ40DE)

INFOID:0000000003935919

COMPONENT INSPECTION

Heater Pump Relay

Check continuity between terminals 3 and 5.

If NG, replace relay.

1 - 50

: Continuity should exist.

1 - Ground

: Continuity should not exist.

AWIIA0263ZZ

Conditions

Continuity

12V direct current supply between terminals 1 and 2

Yes

No current supply

No

LHA160

2009 Pathfinder

HAC-78

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

AMBIENT SENSOR

AMBIENT SENSOR

Component Description

INFOID:0000000003935920

COMPONENT DESCRIPTION

Ambient Sensor

Ambient sensor (1) is attached to the radiator core support (left side). It detects ambient temperature and con-
verts it into a value which is then input into the A/C auto amp.
•

⇐

: Front

AMBIENT TEMPERATURE INPUT PROCESS

The A/C auto amp. includes a processing circuit for the ambient sensor input. However, when the temperature
detected by the ambient sensor increases quickly, the processing circuit retards the A/C auto amp. function. It
only allows the A/C auto amp. to recognize an ambient temperature increase of 0.33

°

C (0.6

°

F) per 100 sec-

onds.
This prevents constant adjustments due to momentary conditions, such as stopping after high speed driving.
Although the actual ambient temperature has not changed, the temperature detected by the ambient sensor
will increase. This is because the heat from the engine compartment can radiate to the front grille area, loca-
tion of the ambient sensor.

Ambient Sensor Diagnosis Procedure

INFOID:0000000003935921

DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR

SYMPTOM: Ambient sensor circuit is open or shorted. (40 or 41 is
indicated on A/C auto amp. as a result of conducting the A/C auto
amp. self-diagnosis)

1.

CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND

1.

Disconnect ambient sensor connector.

2.

Turn ignition switch ON.

3.

Check voltage between ambient sensor harness connector E1
terminal 1 and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> GO TO 4.

AWIIA0262ZZ

AWIIA0160GB

1 - Ground

: Approx. 5V

AWIIA0161ZZ

2009 Pathfinder

AMBIENT SENSOR

HAC-79

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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2.

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

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector.

3.

Check continuity between ambient sensor harness connector
E1 (B) terminal 2 and A/C auto amp. harness connector M49 (A)
terminal 26.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair harness or connector.

3.

CHECK AMBIENT SENSOR

Check the Ambient Sensor Circuit. Refer to 

HAC-79, "Ambient Sensor Component Inspection"

.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-7, "Removal and Installation"

.

2.

GO TO 

HAC-24, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> 1.

Replace ambient sensor.

2.

GO TO 

HAC-24, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

4.

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

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector.

3.

Check continuity between ambient sensor harness connector
E1 (B) terminal 1 and A/C auto amp. harness connector M49 (A)
terminal 25.

4.

Check continuity between ambient sensor harness connector
E1 (B) terminal 1 and ground.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-7, "Removal and Installation"

2.

GO TO 

HAC-24, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> Repair harness or connector.

Ambient Sensor Component Inspection

INFOID:0000000003935922

COMPONENT INSPECTION

Ambient Sensor

2 - 26

: Continuity should exist.

AWIIA1039ZZ

1 - 25

: Continuity should exist.

1 - Ground

: Continuity should not exist.

AWIIA1040ZZ

2009 Pathfinder

HAC-80

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

AMBIENT SENSOR

After disconnecting ambient sensor (1) connector E1, measure
resistance between terminals 1 and 2 at sensor component side,
using the table below.
•

⇐

: Front

NOTE:
The ambient sensor is located behind the front grille, below the hood
latch. The ambient sensor (1) provides input for the automatic A/C
system.

If NG, replace ambient sensor. Refer to 

HA-57, "Removal and Installation"

.

Temperature 

°

C (

°

F)

Resistance k

Ω

 

−

15 (5)

12.73

 

−

10 (14)

9.92

 

−

5 (23)

7.80

0 (32)

6.19

5 (41)

4.95

10 (50)

3.99

15 (59)

3.24

20 (68)

2.65

25 (77)

2.19

30 (86)

1.81

35 (95)

1.51

40 (104)

1.27

45 (113)

1.07

WJIA1981E

2009 Pathfinder

IN-VEHICLE SENSOR

HAC-81

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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IN-VEHICLE SENSOR

Component Description

INFOID:0000000003935923

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:0000000003935924

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

2009 Pathfinder

HAC-82

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

IN-VEHICLE SENSOR

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-83, "In-Vehicle Sensor Component Inspection"

.

Is the inspection result normal?

YES

>> 1.

Replace A/C auto amp. Refer to 

VTL-7, "Removal and Installation"

.

2.

Go to 

HAC-24, "A/C Auto Amp. Self-Diagnosis"

 and perform self-diagnosis.

NO

>> 1.

Replace in-vehicle sensor. Refer to 

VTL-9, "Removal and Installation"

.

2.

Go to 

HAC-24, "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-7, "Removal and Installation"

.

2.

Go to 

HAC-24, "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

2009 Pathfinder