Infiniti F50. Manual - part 384

DTC P0101 MAF SENSOR

EC-177

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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 109.
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 1 and ECM terminal 91.
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 MASS AIR FLOW SENSOR

Refer to 

EC-177, "Component Inspection"

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OK or NG

OK

>> GO TO 9.

NG

>> Replace mass air flow sensor.

9. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

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>> INSPECTION END

Component Inspection

EBS00LXJ

MASS AIR FLOW SENSOR

1.

Reconnect all harness connectors disconnected.

2.

Start engine and warm it up to normal operating temperature.

3.

Check voltage between ECM terminal 91 (Mass air flow sensor
signal) and ground.

*: Make sure linear voltage rises as engine speed increases to about 4,000 rpm.

4.

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

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Turn ignition switch “OFF”.

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

Continuity should exist.

Continuity should exist.

Condition

Voltage V

Ignition switch “ON” (Engine stopped.)

Approx. 1.0

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

1.1 - 1.5

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

1.7 - 2.4

Idle to about 4,000 rpm*

1.1 - 1.5 to Approx. 4.0

PBIB0078E

EC-178

DTC P0101 MAF SENSOR

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Perform steps 2 and 3 again.

5.

If NG, remove mass air flow sensor from air duct. Check hot film for damage or dust.

6.

If NG, clean or replace mass air flow sensor.

Removal and Installation

EBS00LXK

MASS AIR FLOW SENSOR

Refer to 

EM-15, "AIR CLEANER AND AIR DUCT"

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DTC P0102, P0103 MAF SENSOR

EC-179

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DTC P0102, P0103 MAF SENSOR

PFP:22680

Component Description

EBS00LXL

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. It consists of a hot film that is supplied with electric current from
the ECM. The temperature of the hot film is controlled by the ECM a
certain amount. The heat generated by the hot film is reduced as the
intake air flows around it. The more air, the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM
detects the air flow by means of this current change.

CONSULT-II Reference Value in Data Monitor Mode

EBS00LXM

Specification data are reference values.

On Board Diagnosis Logic

EBS00LXN

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 lights up.

SEC266C

MONITOR ITEM

CONDITION

SPECIFICATION

MAS A/F SE-B1

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Engine: After warming up

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Air conditioner switch: OFF

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Selector lever: P or N

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No load

Idle

Approx. 1.1 - 1.5V

2,500 rpm

Approx. 1.7 - 2.4V

CAL/LD VALUE

●

Engine: After warming up

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Selector lever: P or N

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Air conditioner switch: OFF

●

No load

Idle

15% - 35%

2,500 rpm

10% - 35%

MASS AIRFLOW

●

Engine: After warming up

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Selector lever: P or N

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Air conditioner switch: OFF

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No load

Idle

3.8 - 5.2 g·m/s

2,500 rpm

16.0 - 21.5 g·m/s

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. When engine is running.

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Harness or connectors
(The sensor circuit is open or shorted.)

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Intake air leaks

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Mass air flow sensor

P0103
0103

Mass air flow sensor circuit 
high input

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

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Harness or connectors
(The sensor circuit is open or shorted.)

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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.

EC-180

DTC P0102, P0103 MAF SENSOR

DTC Confirmation Procedure

EBS00LXO

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 DTC P0102

 With CONSULT-II

1.

Turn ignition switch “ON”.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Start engine and wait at least 5 seconds.

4.

If DTC is detected, go to 

EC-182, "Diagnostic Procedure"

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 With GST

Follow the procedure “With CONSULT-II” above.

PROCEDURE FOR DTC P0103

 With CONSULT-II 

1.

Turn ignition switch “ON”.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Wait at least 5 seconds.

4.

If DTC is detected, go to 

EC-182, "Diagnostic Procedure"

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If DTC is not detected, go to next step.

5.

Start engine and wait at least 5 seconds.

6.

If DTC is detected, go to 

EC-182, "Diagnostic Procedure"

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 With GST

Follow the procedure “With CONSULT-II” above.

SEF058Y

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