Nissan Pathfinder. Instruction - part 706

B2578, B2579 IN-VEHICLE SENSOR

HAC-85

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

3. Check resistance between in-vehicle sensor terminals.

Is the inspection result normal?

YES

>> Inspection End. 

NO

>> Replace in-vehicle sensor. Refer to 

HAC-159, "Removal and Installation"

.

Terminal

Condition

Resistance: k

Ω

Temperature: 

°C (°F)

1

2

 

−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

HAC-86

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

B257B, B257C AMBIENT SENSOR

B257B, B257C AMBIENT SENSOR

DTC Logic

INFOID:0000000009176824

DTC DETECTION LOGIC 

NOTE:

• If DTC is displayed along with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to 

HAC-

81, "DTC Logic"

.

• If DTC is displayed along with DTC U1010, first perform the trouble diagnosis for DTC U1010. 

HAC-82,

"DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT

1. Turn ignition switch ON.

2. Using CONSULT, perform “SELF-DIAGNOSIS RESULTS” of HVAC. 

3. Check if any DTC No. is displayed in the self-diagnosis results. 
Is DTC detected?

YES

>> Refer to 

HAC-86, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000009176825

Regarding Wiring Diagram information, refer to 

HAC-49, "Wiring Diagram"

.

1.

CHECK AMBIENT SENSOR POWER SUPPLY

1. Turn ignition switch OFF.

2. Disconnect ambient sensor connector.

3. Turn ignition switch ON.

4. Check voltage between ambient sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> GO TO 4.

2.

CHECK AMBIENT SENSOR GROUND CIRCUIT

1. Turn ignition switch OFF.

2. Check continuity between ambient sensor harness connector and ground.

DTC

Items

(CONSULT screen terms)

DTC detection condition

Possible cause

B257B

AMBIENT SENSOR

The ambient sensor recognition temperature is 
too high.

• Ambient sensor
• A/C auto amp.
• Harness or connectors

(The sensor circuit is open or short-
ed.)

B257C

The ambient sensor recognition temperature is 
too low.

+

−

Voltage

(Approx.)

Ambient sensor

Connector

Terminal

E206

1

Ground

5 V

B257B, B257C AMBIENT SENSOR

HAC-87

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair harness or connector.

3.

CHECK AMBIENT SENSOR 

Check ambient sensor. Refer to 

HAC-87, "Component Inspection"

.

Is the inspection result normal?

YES

>> Replace A/C auto amp. Refer to 

HAC-157, "Removal and Installation"

.

NO

>> Replace ambient sensor. Refer to 

HAC-158, "Removal and Installation"

.

4.

CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR OPEN

1. Turn ignition switch OFF.

2. Disconnect A/C auto amp.connector.

3. Check continuity between ambient sensor harness connector and A/C auto amp. harness connector.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair harness or connector.

5.

CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR GROUND SHORT

Check continuity between ambient sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Repair harness or connector.

6.

CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR POWER SHORT

1. Turn ignition switch ON.

2. Check voltage between ambient sensor harness connector and ground.

Is the inspection result normal?

YES

>> Replace A/C auto amp. Refer to 

HAC-157, "Removal and Installation"

.

NO

>> Repair harness or connector.

Component Inspection

INFOID:0000000009176826

1.

CHECK AMBIENT SENSOR

1. Turn ignition switch OFF.

2. Disconnect ambient sensor connector.

Ambient sensor

—

Continuity

Connector

Terminal

E206

2

Ground

Yes

Ambient sensor

A/C auto amp.

Continuity

Connector

Terminal

Connector

Terminal

E206

1

M50

7

Yes

Ambient sensor

—

Continuity

Connector

Terminal

E206

1

Ground

No

+

−

Voltage

(Approx.)

Ambient sensor

Connector

Terminal

E206

1

Ground

0 V

HAC-88

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

B257B, B257C AMBIENT SENSOR

3. Check resistance between ambient sensor terminals.

Is the inspection result normal?

YES

>> Inspection End.

NO

>> Replace ambient sensor. Refer to 

HAC-158, "Removal and Installation"

.

Terminal

Condition

Resistance: k

Ω

Temperature: 

°C (°F)

1

2

 

−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