Infiniti FX35, FX50 (S51). Manual - part 669

P0137, P0157 HO2S2

EC-217

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

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Check the voltage between ECM harness connector terminals under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 3.

3.

PERFORM COMPONENT FUNCTION CHECK-III

Check the voltage between ECM harness connector terminals under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-217, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005236822

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-39, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1.

Clear the mixture ratio self-learning value. Refer to 

EC-28, "MIXTURE RATIO SELF-LEARNING VALUE

CLEAR : Special Repair Requirement"

.

2.

Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0171 or P0174 detected? Is it difficult to start engine?

YES

>> Perform trouble diagnosis for DTC P0171 or P0174. Refer to 

EC-235, "DTC Logic"

.

NO

>> GO TO 3.

3.

CHECK HEATED OXYGEN SENSOR 2 (HO2S2) GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect HO2S2 harness connector.

3.

Disconnect ECM harness connector.

4.

Check the continuity between HO2S2 harness connector and ECM harness connector.

5.

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

Is the inspection result normal?

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

P0137

F102

76

84

Keeping engine at idle for 10 minutes

The voltage should be above 0.70 V at 
least once during this procedure.

P0157

80

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

P0137

F102

76

84

Coasting from 80 km/h (50 MPH) in D po-
sition

The voltage should be above 0.70 V at 
least once during this procedure.

P0157

80

DTC

HO2S2

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0137

1

F54

1

F102

84

Existed

P0157

2

F53

1

EC-218

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0137, P0157 HO2S2

YES

>> GO TO 4.

NO

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

4.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between HO2S2 harness connector and ECM harness connector.

2.

Check the continuity between HO2S2 harness connector or ECM harness connector and ground.

3.

Also check harness for short to power.

Is the inspection result normal?

YES

>> GO TO 5.

NO

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

5.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-218, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

REPLACE HEATED OXYGEN SENSOR 2

Replace malfunctioning 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 [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant
(commercial service tool).

>> INSPECTION END

7.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005236823

1.

INSPECTION START

Will CONSULT-III be used?

Will CONSULT-III be used?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

CHECK HEATED OXYGEN SENSOR 2 (HO2S2)

With CONSULT-III

1.

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

DTC

HO2S2

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0137

1

F54

4

F102

76

Existed

P0157

2

F53

4

80

DTC

HO2S2

ECM

Ground

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0137

1

F54

4

F102

76

Ground

Not existed

P0157

2

F53

4

80

P0137, P0157 HO2S2

EC-219

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

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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.

7.

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

±

25%.

“HO2S2 (B1)/(B2)” should be above 0.70 V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18 V at least once when the “FUEL INJECTION” is 

−

25%.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 6.

3.

CHECK HEATED OXYGEN SENSOR 2-I

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.

Check the voltage between ECM harness connector terminals under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 4.

4.

CHECK HEATED OXYGEN SENSOR 2-II

Check the voltage between ECM harness connector terminals under the following condition.

JMBIA1670GB

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

F102

76

[HO2S2 

(bank 1)]

84

Revving up to 4,000 rpm under no load at 
least 10 times

The voltage should be above 0.70 V at 
least once during this procedure.
The voltage should be below 0.18 V at 
least once during this procedure.

80

[HO2S2 

(bank 2)]

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

F102

76

[HO2S2 

(bank 1)]

84

Keeping engine at idle for 10 minutes

The voltage should be above 0.70 V at 
least once during this procedure.
The voltage should be below 0.18 V at 
least once during this procedure.

80

[HO2S2 

(bank 2)]

EC-220

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0137, P0157 HO2S2

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

CHECK HEATED OXYGEN SENSOR 2-III

Check the voltage between ECM harness connector terminals under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 6.

6.

REPLACE HEATED OXYGEN SENSOR 2

Replace malfunctioning 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 [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant
(commercial service tool).

>> INSPECTION END

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

F102

76

[HO2S2 

(bank 1)]

84

Coasting from 80 km/h (50 MPH) in D po-
sition

The voltage should be above 0.70 V at 
least once during this procedure.
The voltage should be below 0.18 V at 
least once during this procedure.

80

[HO2S2 

(bank 2)]