Nissan Pathfinder (2009 year). Manual - part 262

EC-110

< COMPONENT DIAGNOSIS >

[VQ40DE]

P0075, P0081 IVT CONTROL SOLENOID VALVE

2.

Check resistance between intake valve timing control solenoid
valve as follows.

If NG, replace intake valve timing control solenoid valve.
If OK, go to next step.

3.

Remove intake valve timing control solenoid valve.

4.

Provide 12V DC between intake valve timing control solenoid
valve terminals and then interrupt it. Make sure that the plunger
moves as shown in the figure.

CAUTION:

Never apply 12V DC continuously for 5 seconds or more.
Doing so may result in damage to the coil in intake valve
timing control solenoid valve.
If NG, replace intake valve timing control solenoid valve.
NOTE:
Always replace O-ring when intake valve timing control
solenoid valve is removed.

Terminal

Resistance

1 and 2

7.0 - 7.7

Ω

 at 20

°

C (68

°

F)

1 or 2 and ground

∞Ω

(Continuity should not exist.)

PBIB0193E

PBIB2275E

2009 Pathfinder

P0101 MAF SENSOR

EC-111

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P0101 MAF SENSOR

Component Description

INFOID:0000000004297296

The mass air flow sensor (1) is placed in the stream of intake air. It
measures the intake flow rate by measuring a part of the entire
intake flow. The mass air flow sensor controls the temperature of the
hot wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The greater air flow, the
greater the heat loss.
Therefore, the electric current supplied to hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.

On Board Diagnosis Logic

INFOID:0000000004297297

DTC Confirmation Procedure

INFOID:0000000004297298

Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.

PROCEDURE FOR MALFUNCTION A

NOTE:
If engine will not start or stops soon, wait at least 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.

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.

Run engine for at least 10 seconds at idle speed.

3.

Check 1st trip DTC.

4.

If 1st trip DTC is detected, go to 

EC-113, "Diagnosis Procedure"

.

 With GST

Follow the procedure “With CONSULT-III” above.

PROCEDURE FOR MALFUNCTION B

PBIA9559J

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0101
0101

Mass air flow sensor cir-
cuit range/performance 

A)

A high voltage from the sensor is sent to ECM 
under light load driving condition.

• Harness or connectors

(The sensor circuit is open or 
shorted.)

• Mass air flow sensor
• EVAP control system pressure 

sensor

• Intake air temperature sensor

B)

A low voltage from the sensor is sent to ECM un-
der heavy load driving condition.

• Harness or connectors

(The sensor circuit is open or 
shorted.)

• Intake air leaks
• Mass air flow sensor
• EVAP control system pressure 

sensor

• Intake air temperature sensor

2009 Pathfinder

EC-112

< COMPONENT DIAGNOSIS >

[VQ40DE]

P0101 MAF SENSOR

CAUTION:

Always drive vehicle at a safe speed.

 With CONSULT-III 

1.

Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to 

EC-113, "Diagnosis Procedure"

.

2.

Select “DATA MONITOR” mode with CONSULT-III.

3.

Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.

4.

Increases engine speed to about 4,000 rpm.

5.

Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to 

EC-113, "Diagnosis Procedure"

.

If OK, go to following step.

6.

Maintain the following conditions for at least 10 consecutive seconds.

7.

Check 1st trip DTC.

8.

If 1st trip DTC is detected, go to 

EC-113, "Diagnosis Procedure"

.

Overall Function Check

INFOID:0000000004297299

PROCEDURE FOR MALFUNCTION B

Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip
DTC might not be confirmed.

 With GST

1.

Start engine and warm it up to normal operating temperature.

2.

Select Service $01 with GST.

PBIB3457E

ENG SPEED

More than 2,000 rpm

THRTL SEN 1

More than 1.5 V

THRTL SEN 2

More than 1.5 V

Selector lever

Suitable position

Driving location

Driving vehicle uphill (Increased engine load) will help 
maintain the driving conditions required for this test.

2009 Pathfinder

P0101 MAF SENSOR

EC-113

< COMPONENT DIAGNOSIS >

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3.

Check the mass air flow sensor signal with Service $01.

4.

Check for linear mass air flow sensor signal value rise in
response to increases to about 4,000 rpm in engine speed.

5.

If NG, go to 

EC-113, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000004297300

1.

INSPECTION START

Which malfunction (A or B) is duplicated?
A or B

A

>> GO TO 3.

B

>> GO TO 2.

2.

CHECK INTAKE SYSTEM

Check the following for connection.
• Air duct
• Vacuum hoses
• Intake air passage between air duct and intake manifold

OK or NG

OK

>> GO TO 3.

NG

>> Reconnect the parts.

3.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten three ground screws on the body. Refer to 

EC-95, "Ground Inspection"

.

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace ground connections.

4.

CHECK MAF SENSOR POWER SUPPLY CIRCUIT

1.

Disconnect mass air flow (MAF) sensor harness connector.

2.

Turn ignition switch ON.

SEF534P

BBIA0539E

BBIA0541E

2009 Pathfinder

EC-114

< COMPONENT DIAGNOSIS >

[VQ40DE]

P0101 MAF SENSOR

3.

Check voltage between MAF sensor terminal 2 and ground with
CONSULT-III or tester.

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E2, F32
• Harness for open or short between IPDM E/R and mass air flow sensor
• Harness for open or short between mass air flow sensor and ECM

>> Repair harness or connectors.

6.

CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 7.

NG

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

7.

CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between MAF sensor terminal 4 and ECM terminal 51.
Refer to Wiring Diagram.

2.

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

OK or NG

OK

>> GO TO 8.

NG

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

8.

CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to 

EC-124, "Component Inspection"

.

OK or NG

OK

>> GO TO 9.

NG

>> Replace intake air temperature sensor.

9.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-256, "Component Inspection"

.

OK or NG

OK

>> GO TO 10.

NG

>> Replace EVAP control system pressure sensor.

10.

CHECK MASS AIR FLOW SENSOR

Refer to 

EC-115, "Component Inspection"

.

Voltage: Battery voltage

PBIB1168E

Continuity should exist.

Continuity should exist.

2009 Pathfinder

P0101 MAF SENSOR

EC-115

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OK or NG

OK

>> GO TO 11.

NG

>> Replace mass air flow sensor.

11.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-49, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004297301

MASS AIR FLOW SENSOR

 With CONSULT-III

1.

Reconnect all harness connectors disconnected.

2.

Start engine and warm it up to normal operating temperature.

3.

Connect CONSULT-III and select “DATA MONITOR” mode.

4.

Select “MAS A/F SE-B1” and check indication under the following conditions.

*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.

5.

If the voltage is out of specification, proceed the following.

a.

Check for the cause of uneven air flow through mass air flow sensor. Refer to following.
• Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system parts

b.

If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.

6.

Turn ignition switch OFF.

7.

Disconnect mass air flow sensor harness connector and reconnect it again.

8.

Perform step 2 to 4 again.

9.

If NG, clean or replace mass air flow sensor.

 Without CONSULT-III

1.

Reconnect all harness connectors disconnected.

2.

Start engine and warm it up to normal operating temperature.

3.

Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.

Condition

MAS A/F SE-B1 (V)

Ignition switch ON (Engine stopped.)

Approx. 0.4

Idle (Engine is warmed-up to normal 
operating temperature.)

0.9 - 1.2

2,500 rpm (Engine is warmed-up to 
normal operating temperature.)

1.5 - 1.8

Idle to about 4,000 rpm

0.9 - 1.2 to Approx. 2.4*

Condition

Voltage V

Ignition switch ON (Engine stopped.)

Approx. 0.4

Idle (Engine is warmed-up to normal 
operating temperature.)

0.9 - 1.2

2,500 rpm (Engine is warmed-up to 
normal operating temperature.)

1.5 - 1.8

Idle to about 4,000 rpm

0.9 - 1.2 to Approx. 2.4*

PBIB1106E

2009 Pathfinder

EC-116

< COMPONENT DIAGNOSIS >

[VQ40DE]

P0101 MAF SENSOR

*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.

4.

If the voltage is out of specification, proceed the following.

a.

Check for the cause of uneven air flow through mass air flow sensor. Refer to following.
• Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system parts

b.

If NG, repair or replace malfunctioning part and perform step 2 to 3 again.
If OK, go to next step.

5.

Turn ignition switch OFF.

6.

Disconnect mass air flow sensor harness connector and reconnect it again.

7.

Perform step 2 and 3 again.

8.

If NG, clean or replace mass air flow sensor.

2009 Pathfinder

P0102, P0103 MAF SENSOR

EC-117

< COMPONENT DIAGNOSIS >

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P0102, P0103 MAF SENSOR

Component Description

INFOID:0000000004298007

The mass air flow sensor (1) is placed in the stream of intake air. It
measures the intake flow rate by measuring a part of the entire
intake flow. The mass air flow sensor controls the temperature of the
hot wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The greater air flow, the
greater the heat loss.
Therefore, the electric current supplied to hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.

On Board Diagnosis Logic

INFOID:0000000004297303

These self-diagnoses have the one trip detection logic.

FAIL-SAFE MODE

When the malfunction is detected, the ECM enters fail-safe mode and the MIL illuminate.

DTC Confirmation Procedure

INFOID:0000000004297304

NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing 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.

PROCEDURE FOR DTC P0102

1.

Start engine and wait at least 5 seconds.

2.

Check DTC.

3.

If DTC is detected, go to 

EC-118, "Diagnosis Procedure"

.

PROCEDURE FOR DTC P0103

1.

Turn ignition switch ON and wait at least 5 seconds.

2.

Check DTC.

3.

If DTC is detected, go to 

EC-118, "Diagnosis Procedure"

.

If DTC is not detected, go to next step.

4.

Start engine and wait at least 5 seconds.

5.

Check DTC.

6.

If DTC is detected, go to 

EC-118, "Diagnosis Procedure"

.

PBIA9559J

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

P0102
0102

Mass air flow sensor 
circuit low input

An excessively low voltage from the sensor is sent 
to ECM.

• Harness or connectors

(The sensor circuit is open or shorted.)

• Intake air leaks
• Mass air flow sensor

P0103
0103

Mass air flow sensor 
circuit high input

An excessively high voltage from the sensor is 
sent to ECM.

• Harness or connectors

(The sensor circuit is open or shorted.)

• Mass air flow sensor

Detected items

Engine operating condition in fail-safe mode

Mass air flow sensor circuit

Engine speed will not rise more than 2,400 rpm due to the fuel cut.

2009 Pathfinder