Nissan Pathfinder. Manual - part 473

EC-198

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0102, P0103 MAF SENSOR

1. Reconnect all harness connectors disconnected.

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

3. Connect CONSULT 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 approximately 4,000 rpm.

Without CONSULT

1. Reconnect all harness connectors disconnected.

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 approximately 4,000 rpm.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

CHECK FOR THE CAUSE OF UNEVEN AIR FLOW THROUGH MASS AIR FLOW SENSOR

Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.

• Crushed air ducts

• Malfunctioning seal of air cleaner element

• Uneven dirt of air cleaner element

• Improper specification of intake air system parts
Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

CHECK MASS AIR FLOW SENSOR-II

With CONSULT

1. Repair or replace malfunctioning part.

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

3. Connect CONSULT 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 approximately 4,000 rpm.

Without CONSULT

Monitor item

Condition

MAS A/F SE-B1 (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 approximately 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 approximately 4,000 rpm

0.8 - 1.2 to Approx. 2.4*

Monitor item

Condition

MAS A/F SE-B1 (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 approximately 4,000 rpm

0.8 - 1.2 to Approx. 2.4*

P0102, P0103 MAF SENSOR

EC-199

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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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 approximately 4,000 rpm.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 4.

4.

CHECK MASS AIR FLOW SENSOR-III

With CONSULT

1. Turn ignition switch OFF.

2. Disconnect mass air flow 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 indication under the following conditions.

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

Without CONSULT

1. Turn ignition switch OFF.

2. Disconnect mass air flow 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.

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Clean or replace mass air flow 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 approximately 4,000 rpm

0.8 - 1.2 to Approx. 2.4*

Monitor item

Condition

MAS A/F SE-B1 (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 approximately 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 approximately 4,000 rpm

0.8 - 1.2 to Approx. 2.4*

EC-200

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0111 IAT SENSOR

P0111 IAT SENSOR

DTC Logic

INFOID:0000000009178121

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

INSPECTION START

Is it necessary to erase permanent DTC?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to 

EC-201, "Component Function Check"

.

NOTE:

Use the component function check to check the overall function of the IAT sensor circuit. During this check, a

1st trip DTC might not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to 

EC-201, "Diagnosis Procedure"

.

3.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-

dure before conducting 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.

TESTING CONDITION:

• Before performing the following procedure, do not add fuel.

• Before performing the following procedure, check that fuel level is between 1/4 and 4/4.

• Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.

>> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and let it idle for 60 minutes.

2. Move the vehicle to a cool place.

NOTE:

Cool the vehicle in an environment of ambient air temperature between 

−10°C (14°F) and 35°C (95°F).

3. Turn ignition switch OFF and soak the vehicle for 12 hours.

CAUTION:

Never turn ignition switch ON during soaking.

NOTE:

The vehicle must be cooled with the food open.

4. Start engine and let it idle for 5 minutes or more.

CAUTION:

Never turn ignition switch OFF during idling.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0111

IAT SENSOR 1 B1
(Intake air temperature sensor 1 
circuit range/performance bank 1)

The comparison result of signals transmitted 
to ECM from each temperature sensor (IAT 
sensor, ECT sensor, FTT sensor, and EOT 
sensor) shows that the voltage signal of the 
IAT sensor is higher/lower than that of other 
temperature sensors when the engine is 
started with its cold state.

• Harness or connectors

(High or low resistance in the IAT 
sensor circuit)

• IAT sensor

P0111 IAT SENSOR

EC-201

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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

YES

>> Proceed to 

EC-201, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Component Function Check

INFOID:0000000009178122

1.

CHECK INTAKE AIR TEMPERATURE (IAT) SENSOR

1. Turn ignition switch OFF.

2. Disconnect mass air flow sensor harness connector.

3. Check resistance between mass air flow sensor terminals as follows.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-49, "Intermittent Incident"

.

NO

>> Proceed to 

EC-201, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000009178123

1.

CHECK INTAKE AIR TEMPERATURE (IAT) SENSOR

Check intake air temperature sensor. Refer to 

EC-201, "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, "Exploded View"

.

Component Inspection

INFOID:0000000009178124

1.

CHECK INTAKE AIR TEMPERATURE SENSOR

1. Turn ignition switch OFF.

2. Disconnect mass air flow sensor harness connector.

3. Check resistance between mass air flow sensor terminals as per the following.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace mass air flow sensor. Refer to 

EM-24, "Exploded View"

.

Terminals

Condition

Resistance (k

Ω)

1 and 2

Temperature [

°C (°F)]

25 (77)

1,800 – 2,200

Mass air flow sensor

Condition

Resistance (k

Ω)

+

−

Terminals

2

1

Temperature [

°C (°F)]

25 (77)

1.800 - 2.200