Infiniti FX35 / FX45. Manual - part 375

DTC P0138, P0158 HO2S2

EC-261

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

NG

>> Repair open circuit or short to ground or short to ground or short to power in harness or connec-

tors.

3.

CHECK HEATED OXYGEN SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.

2.

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

3.

Also check harness for short to power.

OK or NG

OK

>> GO TO 4.

NG

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

4.

CHECK HEATED OXYGEN SENSOR 2 CONNECTOR FOR WATER

Check connectors for water.

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace harness or connectors.

5.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-263, "Component Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 2.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-139

.

>> INSPECTION END

PROCEDURE FOR MALFUNCTION B

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

DTC

Terminals

Bank

ECM

Sensor

P0138

74

4

1

P0158

55

4

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0138

74

4

1

P0158

55

4

2

Continuity should not exist.

Water should not exist.

EC-262

< SERVICE INFORMATION >

[VQ35DE]

DTC P0138, P0158 HO2S2

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.

CLEAR THE SELF-LEARNING DATA

 With CONSULT-III

1.

Start engine and warm it up to normal operating temperature.

2.

Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-III.

3.

Clear the self-learning control coefficient by touching “CLEAR”.

4.

Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?

 Without CONSULT-III

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF.

3.

Disconnect mass air flow sensor harness connector, and restart
and run engine for at least 5 seconds at idle speed.

4.

Stop engine and reconnect mass air flow sensor harness con-
nector.

5.

Make sure DTC P0102 is displayed.

6.

Erase the DTC memory. Refer to 

EC-55, "Emission-Related

Diagnostic Information"

.

7.

Make sure DTC P0000 is displayed.

8.

Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0172, P0175. Refer to 

EC-284

.

No

>> GO TO 3.

3.

CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect heated oxygen sensor 2 harness connector.

3.

Disconnect ECM harness connector.

4.

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

5.

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

OK or NG

OK

>> GO TO 4.

NG

>> Repair open circuit or short to ground or short to power

in harness or connectors.

4.

CHECK HEATED OXYGEN SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.

PBIB2625E

PBIB1565E

Continuity should exist.

PBIB1576E

DTC P0138, P0158 HO2S2

EC-263

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

2.

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

3.

Also check harness for 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 HEATED OXYGEN SENSOR 2

Refer to 

EC-263, "Component Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 2.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-139

.

>> INSPECTION END

Component Inspection

INFOID:0000000001583030

HEATED OXYGEN SENSOR 2

 With CONSULT-III

1.

Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.

2.

Start engine and warm it up to the normal operating temperature.

3.

Turn ignition switch OFF and wait at least 10 seconds.

4.

Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.

5.

Let engine idle for 1 minute.

6.

Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select “HO2S2 (B1)/(B2)” as the monitor item
with CONSULT-III.

DTC

Terminals

Bank

ECM

Sensor

P0138

74

4

1

P0158

55

4

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0138

74

4

1

P0158

55

4

2

Continuity should not exist.

EC-264

< SERVICE INFORMATION >

[VQ35DE]

DTC P0138, P0158 HO2S2

7.

Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to 

±

25%.

“HO2S2 (B1)/(B2)” should be above 0.68V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18V at least once when the “FUEL INJECTION” is 

−

25%.

CAUTION:

• Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7

in) onto a hard surface such as a concrete floor; use a new one.

• Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread

Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

 Without CONSULT-III

1.

Start engine and warm it up to the normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.

4.

Let engine idle for 1 minute.

5.

Set voltmeter probes between ECM terminal 74 [HO2S2 (B1) signal] or 55 [HO2S2 (B2) signal] and
ground.

6.

Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.68V at least once during this
procedure.
If the voltage is above 0.68V at step 6, step 7 is not neces-
sary.

7.

Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.

8.

If NG, replace heated oxygen sensor 2.

CAUTION:

• Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7

in) onto a hard surface such as a concrete floor; use a new one.

• Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread

Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Removal and Installation

INFOID:0000000001326091

HEATED OXYGEN SENSOR 2

Refer to 

EM-26

.

PBIB3458E

PBIB1607E