Infiniti FX35 / FX45. Manual - part 512

DTC P0131, P0151 A/F SENSOR 1

EC-809

< SERVICE INFORMATION >

[VK45DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

2

P

A/F sensor 1 heater
(Bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 5V

16

R

A/F sensor 1 (Bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 3.1V

35

G

Approximately 2.6V

56

B

Approximately 2.3V

75

OR

Approximately 2.3V

PBIB1584E

EC-810

< SERVICE INFORMATION >

[VK45DE]

DTC P0131, P0151 A/F SENSOR 1

BANK 2

Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

TBWM1374E

DTC P0131, P0151 A/F SENSOR 1

EC-811

< SERVICE INFORMATION >

[VK45DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)

Diagnosis Procedure

INFOID:0000000001326655

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten three ground screws on the body.
Refer to 

EC-723, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT

1.

Disconnect air fuel ratio (A/F) sensor 1 harness connector.

2.

Turn ignition switch ON.

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

24

P

A/F sensor 1 heater
(Bank 2)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 5V

57

G

A/F sensor 1 (Bank 2)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 2.6V

58

L

Approximately 2.3V

76

R

Approximately 3.1V

77

OR

Approximately 2.3V

PBIB1584E

PBIB2195E

: Vehicle front

1.

A/F sensor 1 (Bank 2) harness con-
nector

2.

A/F sensor 1 (Bank 1) harness con-
nector

PBIB3246E

EC-812

< SERVICE INFORMATION >

[VK45DE]

DTC P0131, P0151 A/F SENSOR 1

3.

Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-III or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E19, F49
• IPDM E/R connector E7
• 10A fuse
• Harness for open or short between A/F sensor 1 and fuse

>> Repair or replace harness or connectors.

4.

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.

4.

Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.

5.

Also check harness for short to power.

OK or NG

OK

>> GO TO 5.

Voltage: Battery voltage

PBIB1683E

A/F sensor 1 terminal

ECM terminal

Bank 1

1

16

2

75

5

35

6

56

Bank 2

1

76

2

77

5

57

6

58

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

1

16

1

76

2

75

2

77

5

35

5

57

6

56

6

58

Continuity should not exist.