Nissan Pathfinder. Manual - part 472

EC-194

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0101 MAF SENSOR

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

Without CONSULT

1. Repair or replace malfunctioning part.

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

3. Check the voltage between ECM harness connector terminals under the following conditions.

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 4.

4.

CHECK MAF SENSOR-III

With CONSULT

1. Turn ignition switch OFF.

2. Disconnect MAF sensor harness connector and reconnect it again.

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

4. Connect CONSULT and select “DATA MONITOR” mode.

5. Select “MAS A/F SE-B1” and check the indication.

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

Without CONSULT

1. Turn ignition switch OFF.

2. Disconnect MAF sensor harness connector and reconnect it again.

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

4. Check the voltage between ECM harness connector terminals under the following conditions.

Monitor item

Condition

Indication (V)

MAS A/F SE-B1

Ignition switch ON (Engine stopped.)

Approx. 0.4

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

0.8 – 1.2

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

1.6 – 1.9

Idle to about 4,000 rpm

0.8 – 1.2 to Approx. 2.4*

ECM

Condition

Voltage (V)

Connector

+

–

Terminal

F52

82

80

Ignition switch ON (Engine stopped.)

Approx. 0.4

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

0.8 – 1.2

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

1.6 – 1.9

Idle to about 4,000 rpm

0.8 – 1.2 to Approx. 2.4*

Monitor item

Condition

Indication (V)

MAS A/F SE-B1

Ignition switch ON (Engine stopped.)

Approx. 0.4

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

0.8 – 1.2

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

1.6 – 1.9

Idle to about 4,000 rpm

0.8 – 1.2 to Approx. 2.4*

P0101 MAF SENSOR

EC-195

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

C

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EC

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Clean or replace MAF sensor. Refer to 

EM-24, "Removal and Installation"

.

ECM

Condition

Voltage (V)

Connector

+

–

Terminal

F52

82

80

Ignition switch ON (Engine stopped.)

Approx. 0.4

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

0.8 – 1.2

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

1.6 – 1.9

Idle to about 4,000 rpm

0.8 – 1.2 to Approx. 2.4*

EC-196

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0102, P0103 MAF SENSOR

P0102, P0103 MAF SENSOR

DTC Logic

INFOID:0000000009178118

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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

ing the next test.

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.
Which DTC is detected?

P0102 >> GO TO 2.

P0103 >> GO TO 3.

2.

PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P0102

1. Start engine and wait at least 5 seconds.

2. Check DTC.
Is DTC detected?

YES

>> Proceed to 

EC-196, "Diagnosis Procedure"

.

NO

>> INSPECTION END

3.

PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P0103-I

1. Turn ignition switch ON and wait at least 5 seconds.

2. Check DTC.
Is DTC detected?

YES

>> Proceed to 

EC-196, "Diagnosis Procedure"

.

NO

>> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P0103-II

1. Start engine and wait at least 5 seconds.

2. Check DTC.
Is DTC detected?

YES

>> Proceed to 

EC-196, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009178119

1.

INSPECTION START

Confirm the detected DTC.
Which DTC is detected?

P0102 >> GO TO 2.

P0103 >> GO TO 3.

2.

CHECK INTAKE SYSTEM

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0102

MAF SEN/CIRCUIT-B1
(Mass or volume air flow 
“A” 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 leakage
• Mass air flow sensor

P0103

MAF SEN/CIRCUIT-B1
(Mass or volume air flow 
“A” 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

P0102, P0103 MAF SENSOR

EC-197

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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Check the following for connection.

• Air duct

• Vacuum hoses

• Intake air passage between air duct to intake manifold
Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Reconnect the parts.

3.

CHECK MAF SENSOR POWER SUPPLY

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

2. Turn ignition switch ON.

3. Check the voltage between MAF sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Perform the trouble diagnosis for power supply circuit.

4.

CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between MAF sensor harness connector and ECM harness connector.

4. Also check harness for short to ground and 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 MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check the continuity between MAF sensor harness connector and ECM harness connector.

2. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 6.

NO

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

6.

CHECK MASS AIR FLOW SENSOR

Check mass air flow sensor. Refer to 

EC-197, "Component Inspection"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-49, "Intermittent Incident"

.

NO

>> Replace mass air flow sensor. Refer to 

EM-24, "Removal and Installation"

.

Component Inspection

INFOID:0000000009178120

1.

CHECK MASS AIR FLOW SENSOR-I

With CONSULT

MAF sensor

Ground

Voltage

Connector

Terminal

F31

5

Ground

Battery voltage

MAF sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F31

4

F52

80

Existed

MAF sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F31

3

F52

82

Existed