Infiniti FX35 / FX45. Manual - part 495

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER

EC-741

< 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-742

< SERVICE INFORMATION >

[VK45DE]

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER

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.

TBWM1372E

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER

EC-743

< 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:0000000001326567

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 connector

2.

A/F sensor 1 (Bank 1) 
harness connector

PBIB3246E

EC-744

< SERVICE INFORMATION >

[VK45DE]

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER

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 HEATER OUTPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between the following;
ECM terminal 2 and A/F sensor 1 (Bank 1) terminal 4 or
ECM terminal 24 and A/F sensor 1 (Bank 2) terminal 4.
Refer to Wiring Diagram.

4.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 5.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

5.

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-744, "Component Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning air fuel ratio sensor 1.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-717

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326568

AIR FUEL RATIO (A/F) SENSOR 1 HEATER

Voltage: Battery voltage

PBIB1683E

Continuity should exist.