Nissan Altima L32. Manual - part 262

P0101 MAF SENSOR

EC-169

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

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3. Select “DATA MONITOR” mode with CONSULT-III.

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

5. Increases engine speed to about 4,000 rpm.

6. Monitor the linear voltage rise in response to engine speed

increases.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Go to 

EC-170, "Diagnosis Procedure"

.

4.

PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B

1. Maintain the following conditions for at least 10 consecutive seconds.

CAUTION:

Always drive vehicle at a safe speed.

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

YES

>> Go to 

EC-170, "Diagnosis Procedure"

.

NO

>> INSPECTION END

5.

PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B

Perform component function check. Refer to 

EC-169, "Component Function Check"

.

NOTE:

Use component function check to check the overall function of the mass air flow sensor circuit. During this

check, a DTC might not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-170, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000004349214

1.

PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B

 With GST

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

2. Select Service $01 with GST.

PBIB3457E

ENG SPEED

More than 1,500 rpm

THRTL SEN 1-B1

More than 3V

THRTL SEN 2-B1

More than 3V

Shift lever

Suitable position

Driving location

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

EC-170

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

P0101 MAF SENSOR

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.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-170, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000004349215

1.

INSPECTION START

Confirm the detected malfunction (A or B). Refer to 

EC-168, "DTC Logic"

.

Which malfunction is detected?

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
Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Reconnect the parts.

3.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in 

GI-45, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace ground connection.

4.

CHECK MAF SENSOR POWER SUPPLY CIRCUIT

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 6.

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.

• Junction block connector E44

• Harness connector E11,F2

• 15A fuse (No. 42)

• Harness for open or short between mass air flow sensor and ECM

• Harness for open or short between mass air flow sensor and IPDM E/R

SEF534P

MAF sensor

Ground

Voltage

Connector

Terminal

F31

5

Ground

Battery voltage

PBIB1169E

P0101 MAF SENSOR

EC-171

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

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>> Repair open circuit or short to ground or short to power in 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 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 7.

NO

>> 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 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 8.

NO

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

8.

CHECK INTAKE AIR TEMPERATURE SENSOR

Check intake air temperature sensor.

Refer to 

EC-182, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Replace mass air flow sensor (with intake air temperature sensor).

9.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-318, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> Replace EVAP control system pressure sensor.

10.

CHECK MASS AIR FLOW SENSOR

Refer to 

EC-171, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 11.

NO

>> Replace mass air flow sensor.

11.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004349216

1.

CHECK MASS AIR FLOW SENSOR-I

MAF sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F31

4

F13

56

Existed

MAF sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F31

3

F13

58

Existed

EC-172

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

P0101 MAF SENSOR

With CONSULT-III

1. Turn ignition switch OFF.

2. Reconnect all harness connectors disconnected.

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

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

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

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

Without CONSULT-III

1. Turn ignition switch OFF.

2. Reconnect all harness connectors disconnected.

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

4. Check the voltage between ECM harness connector and

ground.

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

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 2.

2.

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

1. Turn ignition switch OFF.

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

-

Crushed air ducts

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Malfunctioning seal of air cleaner element

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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-III

1. Repair or replace malfunctioning part.

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.

Monitor item

Condition

MAS A/F SE-B1

MAS A/F SE-B1

Ignition switch ON (Engine stopped.)

Approx. 0.4 V

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

0.9 - 1.1 V

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

1.4 - 1.7 V

Idle to about 4,000 rpm

0.9 - 1.1 V to Approx. 2.4 V*

ECM

Ground

Condition

Voltage

Connector

Terminal

F13

58

(MAF 

sensor 
signal)

Ground

Ignition switch ON (Engine 
stopped.)

Approx. 0.4 V

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

0.9 - 1.1 V

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

1.4 - 1.7 V

Idle to about 4,000 rpm

0.9 - 1.1 V to 

Approx. 2.4 V*

PBIB3481E