Infiniti FX35 / FX45. Manual - part 374

DTC P0138, P0158 HO2S2

EC-257

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Wiring Diagram

INFOID:0000000001326088

BANK 1

Specification data are reference values and are measured between each terminal and ground.

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.

TBWM1592E

EC-258

< SERVICE INFORMATION >

[VQ35DE]

DTC P0138, P0158 HO2S2

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

25

P

Heated oxygen sensor 2 
heater (bank 1)

[Engine is running]
• Engine speed: Below 3,600 rpm after the fol-

lowing conditions are met

- Engine: After warming up
- Keeping the engine speed between 3,500 

and 4,000 rpm for 1 minute and at idle for 1 
minute under no load

0 - 1.0V

[Ignition switch: ON]
• Engine stopped
[Engine is running]
• Engine speed: Above 3,600 rpm

BATTERY VOLTAGE
(11 - 14V)

74

LG/B

Heated oxygen sensor 2 
(bank 1)

[Engine is running]
• Revving engine from idle to 3,000 rpm quick-

ly after the following conditions are met

- Engine: After warming up
- Keeping the engine speed between 3,500 

and 4,000 rpm for 1 minute and at idle for 1 
minute under no load

0 - Approximately 1.0V

78

B/R

Sensor ground
(Heated oxygen sensor)

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

Approximately 0V

DTC P0138, P0158 HO2S2

EC-259

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

BANK 2

Specification data are reference values and are measured between each terminal and ground.

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.

TBWM1593E

EC-260

< SERVICE INFORMATION >

[VQ35DE]

DTC P0138, P0158 HO2S2

Diagnosis Procedure

INFOID:0000000001326089

PROCEDURE FOR MALFUNCTION A

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screw on the body. Refer to 

EC-144, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Disconnect heated oxygen sensor 2 harness connector.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between HO2S2 terminal 1 and ECM
terminal 78.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 3.

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

6

R

Heated oxygen sensor 2 
heater (bank 2)

[Engine is running]
• Engine speed: Below 3,600 rpm after the fol-

lowing conditions are met

- Engine: After warming up
- Keeping the engine speed between 3,500 

and 4,000 rpm for 1 minute and at idle for 1 
minute under no load

0 - 1.0V

[Ignition switch: ON]
• Engine stopped
[Engine is running]
• Engine speed: Above 3,600 rpm

BATTERY VOLTAGE
(11 - 14V)

55

W/R

Heated oxygen sensor 2 
(bank 2)

[Engine is running]
• Revving engine from idle to 3,000 rpm quick-

ly after the following conditions are met

- Engine: After warming up
- Keeping the engine speed between 3,500 

and 4,000 rpm for 1 minute and at idle for 1 
minute under no load

0 - Approximately 1.0V

78

B/R

Sensor ground
(Heated oxygen sensor)

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

Approximately 0V

PBIB2625E

Continuity should exist.

PBIB1576E