Infiniti FX35 / FX45. Manual - part 500

 

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Infiniti FX35 / FX45. Manual - part 500

 

 

DTC P0101 MAF SENSOR

EC-761

< SERVICE INFORMATION >

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DTC P0101 MAF SENSOR

Component Description

INFOID:0000000001326586

The mass air flow sensor is placed in the stream of intake air. It mea-
sures 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 more air, 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.

CONSULT-III Reference Value in Data Monitor Mode

INFOID:0000000001326587

Specification data are reference values.

On Board Diagnosis Logic

INFOID:0000000001326588

DTC Confirmation Procedure

INFOID:0000000001326589

Perform PROCEDURE FOR MALFUNCTION A first.
If DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

PROCEDURE FOR MALFUNCTION A

NOTE:

PBIB1604E

MONITOR ITEM

CONDITION

SPECIFICATION

MAS A/F SE-B1

See 

EC-709

.

CAL/LD VALUE

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No  load

Idle

14% - 33%

2,500 rpm

12% - 25%

MASS AIRFLOW

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No  load

Idle

2.0 - 6.0 g·m/s

2,500 rpm

7.0 - 20.0 g·m/s

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

EC-762

< SERVICE INFORMATION >

[VK45DE]

DTC P0101 MAF SENSOR

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.

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-764, "Diagnosis Procedure"

.

PROCEDURE FOR MALFUNCTION B

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-764, "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-764, "Diagnosis Procedure"

.

If OK, go to following step.

6.

Maintain the following conditions for at least 10 consecutive sec-
onds.

7.

Check 1st trip DTC.

8.

If 1st trip DTC is detected, go to 

EC-764, "Diagnosis Procedure"

.

Overall Function Check

INFOID:0000000001326590

PROCEDURE FOR MALFUNCTION B

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

 With GST

1.

Start engine and warm it up to normal operating temperature.

2.

Select “Service $01” with GST.

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-764, "Diagnosis Procedure"

.

ENG SPEED

More than 2,000 rpm

THRTL SEN 1

More than 3V

THRTL SEN 2

More than 3V

Selector lever

Suitable position

Driving location

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

PBIB3457E

SEF534P

DTC P0101 MAF SENSOR

EC-763

< SERVICE INFORMATION >

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Wiring Diagram

INFOID:0000000001326591

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

TBWM1327E

EC-764

< SERVICE INFORMATION >

[VK45DE]

DTC P0101 MAF SENSOR

Diagnosis Procedure

INFOID:0000000001326592

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-723, "Ground Inspection"

.

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace ground connections.

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

51

L/W

Mass air flow sensor

[Engine is running]
• Warm-up condition
• Idle speed

1.0 - 1.3V

[Engine is running]
• Warm-up condition
• Engine speed: 2,500 rpm

1.6 - 2.0V

67

B/W

Sensor ground

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 0V

111

W/B

ECM relay
(Self shut-off)

[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition 

switch OFF

0 - 1.5V

[Ignition switch: OFF]
• More than a few seconds after turning igni-

tion switch OFF

BATTERY VOLTAGE
(11 - 14V)

119

120

R
R/B

Power supply for ECM

[Ignition switch: ON]

BATTERY VOLTAGE
(11 - 14V)

PBIB2195E

 

 

 

 

 

 

 

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