Infiniti QX56 (Z62). Manual - part 797

B257B, B257C AMBIENT SENSOR

HAC-79

< 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

>> INSPECTION END

NO

>> Replace ambient sensor. Refer to 

HAC-147, "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-80

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

B2581, B2582 INTAKE SENSOR

B2581, B2582 INTAKE SENSOR

DTC Logic

INFOID:0000000006275915

DTC DETECTION LOGIC 

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

HAC-

72, "DTC Logic"

.

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

HAC-73,

"DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1.

Turn ignition switch ON.

2.

Select “Self Diagnostic Result” mode of “HVAC” using CONSULT-III.

3.

Check DTC.

Is DTC detected?

YES

>> Refer to 

HAC-80, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006275916

1.

CHECK INTAKE SENSOR POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect intake sensor connector.

3.

Turn ignition switch ON.

4.

Check voltage between intake sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> GO TO 4.

2.

CHECK INTAKE SENSOR GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector.

3.

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

Is the inspection result normal?

DTC

Items

(CONSULT-III screen terms)

DTC detection condition

Possible cause

B2581

INTAKE SENSOR

The intake sensor recognition temperature is 
too high.

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

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

B2582

The intake sensor recognition temperature is 
too low.

+

−

Voltage

(Approx.)

Intake sensor

Connector

Terminal

M257

1

Ground

5 V

Intake sensor

—

Continuity

Connector

Terminal

M257

2

Ground

Existed

B2581, B2582 INTAKE SENSOR

HAC-81

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

YES

>> GO TO 3.

NO

>> Repair harness or connector.

3.

CHECK INTAKE SENSOR

Check intake sensor. Refer to 

HAC-81, "Component Inspection"

.

Is the inspection result normal?

YES

>> Replace A/C auto amp.. Refer to 

HAC-146, "Removal and Installation"

.

NO

>> Replace intake sensor. Refer to 

HAC-150, "Removal and Installation"

.

4.

CHECK INTAKE SENSOR POWER SUPPLY CIRCUIT FOR OPEN

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. connector.

3.

Check continuity between intake 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 INTAKE SENSOR POWER SUPPLY CIRCUIT FOR GROUND SHORT

Check continuity between intake sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Repair harness or connector.

6.

CHECK INTAKE SENSOR POWER SUPPLY CIRCUIT FOR POWER SHORT

1.

Turn ignition switch ON.

2.

Check voltage between intake sensor harness connector and ground.

Is the inspection result normal?

YES

>> Replace A/C auto amp.. Refer to 

HAC-146, "Removal and Installation"

.

NO

>> Repair harness or connector.

Component Inspection

INFOID:0000000006275917

1.

CHECK INTAKE SENSOR

1.

Turn ignition switch OFF.

2.

Disconnect intake sensor connector.

3.

Check resistance between intake sensor terminals.

Intake sensor

A/C auto amp.

Continuity

Connector

Terminal

Connector

Terminal

M257

1

M50

28

Existed

Intake sensor

—

Continuity

Connector

Terminal

M257

1

Ground

Not existed

+

−

Voltage

(Approx.)

Intake sensor

Connector

Terminal

M257

1

Ground

0 V

HAC-82

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

B2581, B2582 INTAKE SENSOR

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace intake sensor. Refer to 

HAC-150, "Removal and Installation"

.

Terminal

Condition

Resistance: k

Ω

Temperature: 

°

C (

°

F)

1

2

−

15 (5)

17.73

−

10 (14)

13.46

−

5 (23)

10.33

0 (32)

8.00

5 (41)

6.25

10 (50)

4.93

15 (59)

3.92

20 (68)

3.14

25 (77)

2.54

30 (86)

2.06

35 (95)

1.69

40 (104)

1.39

45 (113)

1.15