Nissan Frontier. Manual - part 531

P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D A/F SENSOR 1

EC-695

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

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

6. Let engine idle for 1 minute.

7. Increase the engine speed up to about 3,600 rpm and keep it for 10 seconds.

8. Fully release accelerator pedal and then let engine idle for about 1 minute.

9. Check the items status of “DATA MONITOR” as follows.

NOTE:

If “PRSNT” changed to “ABSNT”, refer to 

EC-666, "Overall Function Check"

.

Is “PRSNT” displayed on CONSULT screen?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE-2

With CONSULT

Perform DTC confirmation procedure-1 again.
Is “PRSNT” displayed on CONSULT screen?

YES

>> GO TO 4.

NO

>> Refer to 

EC-666, "Overall Function Check"

.

4.

PERFORM DTC CONFIRMATION PROCEDURE-2

With CONSULT

1. Wait for about 20 seconds at idle.

2. Check the items status of “DATA MONITOR” as follows.

NOTE:

If “CMPLT” changed to “INCMP”, refer to 

EC-666, "Overall Function Check"

.

Is “CMPLT” displayed on CONSULT screen?

YES

>> GO TO 5.

NO

>> Refer to 

EC-666, "Overall Function Check"

.

5.

PERFORM SELF-DIAGNOSIS

With CONSULT

Check the “SELF-DIAG RESULT”.
Is any DTC detected?

YES

>> Proceed to 

EC-696, "Diagnosis Procedure"

.

NO

>> INSPECTION END

6.

CHECK AIR-FUEL RATIO SELF-LEARNING VALUE

With GST

DTC

Data monitor item

Status

• P014C
• P014D
• P015A
• P015B

A/F SEN1 DIAG3 (B1)

PRSNT

• P014E
• P014F
• P015C
• P015D

A/F SEN1 DIAG3 (B2)

DTC

Data monitor item

Status

• P014C
• P014D
• P015A
• P015B

A/F SEN1 DIAG1 (B1)

CMPLT

A/F SEN1 DIAG2 (B1)

• P014E
• P014F
• P015C
• P015D

A/F SEN1 DIAG1 (B2)

A/F SEN1 DIAG2 (B2)

EC-696

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D A/F SENSOR 1

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

2. Select Service $01 with GST.

3. Calculate the total value of “Short term fuel trim” and “Long term fuel trim” indications.
Is the total percentage within 

±15%?

YES

>> GO TO 8.

NO

>> GO TO 7.

7.

DETECT MALFUNCTIONING PART

Check the following.

• Intake air leaks

• Exhaust gas leaks

• Incorrect fuel pressure

• Lack of fuel

• Fuel injector

• Incorrect PCV hose connection

• PCV valve

• Mass air flow sensor

>> Repair or replace malfunctioning part.

8.

PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

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. Increase the engine speed up to about 3,600 rpm and keep it for 10 seconds.

7. Fully release accelerator pedal and then let engine idle for about 1 minute.

8. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Proceed to 

EC-696, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010232191

1.

RETIGHTEN A/F SENSOR 1

Loosen and retighten the A/F sensor 1. Refer to 

EM-147, "Exploded View"

.

>> GO TO 2.

2.

CHECK EXHAUST GAS LEAK

1. Start engine and run it at idle.

2. Listen for an exhaust gas leak before three way catalyst 1.

Is exhaust gas leak detected?

YES

>> Repair or replace.

NO

>> GO TO 3.

3.

CHECK FOR INTAKE AIR LEAK

PBIB1922E

P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D A/F SENSOR 1

EC-697

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

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Listen for an intake air leak after the mass air flow sensor.
Is intake air leak detected?

YES

>> Repair or replace.

NO

>> GO TO 4.

4.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1. Clear the mixture ratio self-learning value. Refer to 

EC-594, "Work Procedure"

.

2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected? Is it difficult to start engine?

YES

>> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to 

EC-700, "On Board

Diagnosis Logic"

 or 

EC-706, "On Board Diagnosis Logic"

.

NO

>> GO TO 5.

5.

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

1. Disconnect A/F sensor 1 harness connector.

2. Turn ignition switch ON.

3. Check the voltage between A/F sensor 1 harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

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

1. Turn ignition switch OFF.

2. Disconnect IPDM E/R harness connector.

3. Check the continuity between A/F sensor 1 harness connector and IPDM E/R harness connector.

Is the inspection result normal?

YES

>> Perform the trouble diagnosis for power supply circuit.

NO

>> Repair or replace error-detected parts.

7.

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

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

DTC

A/F sensor 1

Ground

Voltage

Bank

Connector

Terminal

• P014C
• P014D
• P015A
• P015B

1

F71

4

Ground

Battery voltage

• P014E
• P014F
• P015C
• P015D

2

F2

4

DTC

A/F sensor 1

IPDM E/R

Continuity

Bank

Connector

Terminal

Connector

Terminal

• P014C
• P014D
• P015A
• P015B

1

F71

4

E119

8

Existed

• P014E
• P014F
• P015C
• P015D

2

F2

4

EC-698

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D A/F SENSOR 1

4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector

and ground.

5. Also check harness for short to power.
Is the inspection result normal?

YES

>> GO TO 8.

NO

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

8.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER

Check air fuel ratio (A/F) sensor 1 heater. Refer to 

EC-625, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Replace malfunctioning air fuel ratio (A/F) sensor 1. Refer to 

EM-147, "Exploded View"

.

9.

CHECK MASS AIR FLOW SENSOR

Check both mass air flow sensor (bank 1 and bank 2). Refer to 

EC-635, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 10. 

NO

>> Replace malfunctioning mass air flow sensor. Refer to 

EM-141, "Removal and Installation"

.

10.

CHECK PCV VALVE

Check PCV valve. Refer to 

EC-945, "Component Inspection"

.

Is the inspection result normal?

DTC

A/F sensor 1

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

• P014C
• P014D
• P015A
• P015B

1

F71

1

F57

69

Existed

2

73

• P014E
• P014F
• P015C
• P015D

2

F2

1

77

2

81

DTC

A/F sensor 1

Ground

Continuity

Bank

Connector

Terminal

• P014C
• P014D
• P015A
• P015B

1

F71

1

Ground

Not existed

2

• P014E
• P014F
• P015C
• P015D

2

F2

1

2

DTC

ECM

Ground

Continuity

Bank

Connector

Terminal

• P014C
• P014D
• P015A
• P015B

1

F57

69

Ground

Not existed

73

• P014E
• P014F
• P015C
• P015D

2

77

81