Infiniti M35/M45 Y50. Manual - part 612

DTC P0102, P0103 MAF SENSOR

EC-921

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EC

a.

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

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Crushed air ducts

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Malfunctioning seal of air cleaner element

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Uneven dirt of air cleaner element

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Improper specification of intake air system parts

b.

If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.

6.

Turn ignition switch OFF.

7.

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

8.

Perform step 2 to 4 again.

9.

If NG, clean or replace mass air flow sensor.

 Without CONSULT-II

1.

Reconnect all harness connectors disconnected.

2.

Start engine and warm it up to normal operating temperature.

3.

Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.

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

4.

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

a.

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

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Crushed air ducts

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Malfunctioning seal of air cleaner element

●

Uneven dirt of air cleaner element

●

Improper specification of intake air system parts

b.

If NG, repair or replace malfunctioning part and perform step 2 to 3 again.
If OK, go to next step.

5.

Turn ignition switch OFF.

6.

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

7.

Perform step 2 and 3 again.

8.

If NG, clean or replace mass air flow sensor.

Removal and Installation

NBS005CL

MASS AIR FLOW SENSOR

Refer to 

EM-177, "AIR CLEANER AND AIR DUCT"

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Condition

Voltage V

Ignition switch ON (Engine stopped.)

Approx. 0.4

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

0.9 - 1.2

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

1.6 - 1.9

Idle to about 4,000 rpm

0.9 - 1.2 to Approx. 2.4*

PBIB1106E

EC-922

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DTC P0112, P0113 IAT SENSOR

DTC P0112, P0113 IAT SENSOR

PFP:22630

Component Description

NBS005CM

The intake air temperature sensor is built-into mass air flow sensor
(1). The sensor detects intake air temperature and transmits a signal
to the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

<Reference data>

*: This data is reference value and is measured between ECM terminal 34 (Intake air
temperature sensor) and ground.

CAUTION:

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

On Board Diagnosis Logic

NBS005CN

DTC Confirmation Procedure

NBS005CO

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.

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Wait at least 5 seconds.

4.

If 1st trip DTC is detected, go to 

EC-924, "Diagnostic Procedure"

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 WITH GST

Follow the procedure “WITH CONSULT-II” above.

PBIA9559J

Intake air temperature

°

C (

°

F)

Voltage*

V

Resistance

k

Ω

25 (77)

3.3

1.800 - 2.200

80 (176)

1.2

0.283 - 0.359

SEF012P

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0112
0112

Intake air temperature 
sensor circuit low input

An excessively low 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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Intake air temperature sensor

P0113
0113

Intake air temperature 
sensor circuit high input

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

SEF058Y

DTC P0112, P0113 IAT SENSOR

EC-923

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EC

Wiring Diagram

NBS005CP

TBWT1017E

EC-924

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DTC P0112, P0113 IAT SENSOR

Diagnostic Procedure

NBS005CQ

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screws on the body.
Refer to 

EC-864, "Ground Inspection"

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OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2. 

CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

1.

Disconnect mass air flow sensor (intake air temperature sensor
is built-into) (1) harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between mass air flow sensor terminal 5 and
ground with CONSULT-II or tester.

OK or NG

OK

>> GO TO 3.

NG

>> Repair open circuit or short to ground or short to power

in harness or connectors.

1.

Body ground M70

2.

Body ground M16

PBIB2782E

PBIB2682E

Voltage: Approximately 5V

PBIB1169E