Nissan Pathfinder (2009 year). Manual - part 330

EC-654

< COMPONENT DIAGNOSIS >

[VK56DE]

P0139, P0159 HO2S2

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 P0171, P0172, P0174 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 (1) harness connector.

-

: Vehicle front

4.

Restart engine and let it idle for at least 5 seconds.

5.

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

6.

Check that DTC P0102 is displayed.

7.

Erase the DTC memory. Refer to 

EC-525, "Emission-related

Diagnostic Information"

.

8.

Check that DTC P0000 is displayed.

9.

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 or No

Yes

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

EC-659, "Diagnosis

Procedure"

 or 

EC-663, "Diagnosis Procedure"

.

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 (HO2S2) harness connector.

3.

Disconnect ECM harness connector.

4.

Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.
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.

ALBIA0353ZZ

1.

Heated oxygen sensor 2 (bank 1) 
harness connector

2.

Heated oxygen sensor 2 (bank 1)

3.

Heated oxygen sensor 2 (bank 2) 
harness connector

4.

Heated oxygen sensor 2 (bank 2)

Continuity should exist.

ALBIA0365ZZ

2009 Pathfinder

P0139, P0159 HO2S2

EC-655

< COMPONENT DIAGNOSIS >

[VK56DE]

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4.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal and HO2S2 terminal as per the following.
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 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-655, "Component Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 2.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-49, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004355619

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

P0139

55

1

1

P0159

74

1

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0139

55

1

1

P0159

74

1

2

Continuity should not exist.

2009 Pathfinder

EC-656

< COMPONENT DIAGNOSIS >

[VK56DE]

P0139, P0159 HO2S2

7.

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

±

 25%.

“HO2S2 (B1)/(B2)” should be above 0.58 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%.

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 heated 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 Lubri-
cant (Commercial service tool).

 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 55 [HO2S2 (B1) signal] and ground, or 74 [HO2S2 (B2) sig-
nal] 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 0.58 V at least once during
this procedure.
The voltage should be below 0.18 V at least once during this
procedure.
If the voltage can be confirmed at step 6, step 7 is not nec-
essary.

7.

Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in the
D position.
The voltage should be above 0.58 V at least once during this procedure.
The voltage should be below 0.18 V 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 heated 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 Lubri-
cant (Commercial service tool).

JMBIA0605GB

PBIB2054E

2009 Pathfinder

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-657

< COMPONENT DIAGNOSIS >

[VK56DE]

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P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

On Board Diagnosis Logic

INFOID:0000000003936587

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from A/F sensor 1. The ECM calculates
the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too lean), the
ECM judges the condition as the fuel injection system malfunction and illuminates the MIL (2 trip detection
logic).

DTC Confirmation Procedure

INFOID:0000000003936588

NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.

 WITH CONSULT-III

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON.

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-III.

6.

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

7.

Start engine.
If it is difficult to start engine, the fuel injection system has a malfunction.
Performing the following procedure is advised.

a.

Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.

b.

If engine starts, go to 

EC-659, "Diagnosis Procedure"

.

If engine does not start, check exhaust and intake air leakage visually.

8.

Keep engine at idle for at least 5 minutes.

9.

Check 1st trip DTC.

10. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go to 

EC-

659, "Diagnosis Procedure"

.

NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.

Sensor

Input signal to ECM

ECM function

Actuator

A/F sensor 1

Density of oxygen in exhaust gas
(Mixture ratio feedback signal)

Fuel injection control

Fuel injector

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0171
0171
(Bank 1)

Fuel injection system too 
lean

• Fuel injection system does not operate properly.
• The amount of mixture ratio compensation is too 

large. (The mixture ratio is too lean.)

• Intake air leakage
• A/F sensor 1
• Fuel injector
• Exhaust gas leakage
• Incorrect fuel pressure
• Lack of fuel
• Mass air flow sensor
• Incorrect PCV hose connection

P0174
0174
(Bank 2)

2009 Pathfinder

EC-658

< COMPONENT DIAGNOSIS >

[VK56DE]

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

a.

Turn ignition switch OFF and wait at least 10 seconds.

b.

Start engine.

c.

Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.

CAUTION:

Always drive vehicle at a safe speed.

d.

Check 1st trip DTC.

e.

If 1st trip DTC is detected, go to 

EC-659, "Diagnosis Procedure"

.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON.

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Disconnect mass air flow sensor (1) harness connector.
•

 : Vehicle front

6.

Restart engine and let it idle for at least 5 seconds.

7.

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

8.

Select Service $03 with GST. Check that DTC P0102 is
detected.

9.

Select Service $04 with GST and erase the DTC P0102.

10. Start engine.

If it is difficult to start engine, the fuel injection system has a mal-
function.
Performing the following procedure is advised.

a.

Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.

b.

If engine starts, go to 

EC-659, "Diagnosis Procedure"

.

If engine does not start, check exhaust and intake air leakage visually.

11. Keep engine at idle for at least 5 minutes.

12. Check 1st trip DTC.
13. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go to 

EC-

659, "Diagnosis Procedure"

.

NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.

a.

Turn ignition switch OFF and wait at least 10 seconds.

b.

Start engine.

c.

Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.

CAUTION:

Always drive vehicle at a safe speed.

d.

Check 1st trip DTC.

e.

If 1st trip DTC is detected, go to 

EC-659, "Diagnosis Procedure"

.

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

ALBIA0353ZZ

2009 Pathfinder

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-659

< COMPONENT DIAGNOSIS >

[VK56DE]

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Diagnosis Procedure

INFOID:0000000003936589

1.

CHECK EXHAUST GAS LEAKAGE

1.

Start engine and run it at idle.

2.

Listen for an exhaust gas leakage before three way catalyst (manifold).

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace malfunctioning part.

2.

CHECK FOR INTAKE AIR LEAKAGE

1.

Listen for an intake air leakage after the mass air flow sensor.

2.

Check PCV hose connection.

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace malfunctioning part.

3.

CHECK AIR FUEL RATIO SENSOR 1 INPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect corresponding air fuel ratio (A/F) sensor 1 harness connector.

3.

Disconnect ECM harness connector.

4.

Check harness continuity between A/F sensor 1 terminals and ECM terminals as per the following.
Refer to Wiring Diagram.

PBIB1216E

1.

A/F sensor 1 (bank 2) harness connector

2.

A/F sensor 1 (bank 2)

3.

A/F sensor 1 (bank 1)

4.

A/F sensor 1 (bank 1) harness connector

: Vehicle front

A/F sensor 1 terminal

ECM terminal

Bank 1

1

35

2

56

Bank 2

1

16

2

75

Continuity should exist.

ALBIA0360ZZ

2009 Pathfinder

EC-660

< COMPONENT DIAGNOSIS >

[VK56DE]

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

5.

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

6.

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 FUEL PRESSURE

1.

Release fuel pressure to zero. Refer to 

EC-951, "Fuel Pressure Check"

.

2.

Install fuel pressure gauge and check fuel pressure. Refer to 

EC-951, "Fuel Pressure Check"

.

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.
• Fuel pump and circuit (Refer to 

EC-869, "Diagnosis Procedure"

.)

• Fuel pressure regulator (Refer to 

EC-951, "Fuel Pressure Check"

.)

• Fuel lines (Refer to 

FL-5, "Checking Fuel Line"

.)

• Fuel filter for clogging

>> Repair or replace malfunctioning part.

6.

CHECK MASS AIR FLOW SENSOR

 With CONSULT-III

1.

Install all removed parts.

2.

Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.

 With GST

1.

Install all removed parts.

2.

Check mass air flow sensor signal in Service $01 with GST.

OK or NG

OK

>> GO TO 7.

NG

>>  Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or

grounds. Refer to 

EC-595, "Diagnosis Procedure"

.

7.

CHECK FUNCTION OF FUEL INJECTOR

 With CONSULT-III

1.

Start engine.

2.

Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-III.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

1

35

1

16

2

56

2

75

Continuity should not exist.

At idling: Approximately 350 kPa (3.57 kg/cm

2

, 51 psi)

3.0 - 9.0 g·m/sec:

At idling

9.0 - 28.0 g·m/sec:

At 2,500 rpm

3.0 - 9.0 g·m/sec:

at idling

9.0 - 28.0 g·m/sec:

at 2,500 rpm

2009 Pathfinder

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-661

< COMPONENT DIAGNOSIS >

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3.

Check that each circuit produces a momentary engine speed drop.

 Without CONSULT-III

1.

Start engine.

2.

Listen to each fuel injector operating sound.

OK or NG

OK

>> GO TO 8.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-866, "Diagnosis Procedure"

.

8.

CHECK FUEL INJECTOR

1.

Confirm that the engine is cooled down and there are no fire hazards near the vehicle.

2.

Turn ignition switch OFF.

3.

Disconnect all fuel injector harness connectors.

4.

Remove fuel injector gallery assembly. Refer to 

EM-182, "Removal and Installation"

.

Keep fuel hose and all fuel injectors connected to fuel injector gallery.

5.

For DTC P0171, reconnect fuel injector harness connectors on bank 1.
For DTC P0174, reconnect fuel injector harness connectors on bank 2.

6.

Disconnect all ignition coil harness connectors.

7.

Prepare pans or saucers under each fuel injector.

8.

Crank engine for approximately 3 seconds.
For DTC P0171, check that fuel sprays out from fuel injectors on
bank 1.
For DTC P0174, check that fuel sprays out from fuel injectors on
bank 2.

OK or NG

OK

>> GO TO 9.

NG

>> Replace fuel injectors from which fuel does not spray

out. Always replace O-ring with new ones.

9.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-49, "Intermittent Incident"

.

>> INSPECTION END

Clicking noise should be heard.

PBIB1986E

Fuel should be sprayed evenly for each fuel injector.

PBIB1726E

2009 Pathfinder