Infiniti FX35 / FX45. Manual — part 357

DTC P0112, P0113 IAT SENSOR

EC-189

< SERVICE INFORMATION >

[VQ35DE]

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DTC P0112, P0113 IAT SENSOR

Component Description

INFOID:0000000001326006

The intake air temperature (IAT) sensor is built-into mass air flow
sensor. 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 values 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

INFOID:0000000001326007

DTC Confirmation Procedure

INFOID:0000000001326008

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.
1.

Turn ignition switch ON and wait at least 5 seconds.

2.

Check 1st trip DTC.

3.

If 1st trip DTC is detected, go to

EC-190, "Diagnosis Procedure"

.

PBIB1604E

Intake air temperature

°

C (

°

F)

Voltage*

V

Resistance

k

Ω

25 (77)

3.30

1.800 - 2.200

80 (176)

1.22

0.283 - 0.359

SEF012P

DTC No.

Trouble diagnosis

name

DTC detecting condition

Possible cause

P0112
0112

Intake air tempera-
ture sensor circuit
low input

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

• Harness or connectors

(Intake air temperature sensor circuit is open
or shorted.)

• Intake air temperature sensor

P0113
0113

Intake air tempera-
ture sensor circuit
high input

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

EC-190

< SERVICE INFORMATION >

[VQ35DE]

DTC P0112, P0113 IAT SENSOR

Wiring Diagram

INFOID:0000000001326009

Diagnosis Procedure

INFOID:0000000001326010

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

TBWM0288E

DTC P0112, P0113 IAT SENSOR

EC-191

< SERVICE INFORMATION >

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2.

Loosen and retighten ground screw on the body. Refer to

EC-144, "Ground Inspection"

.

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 (with intake air temperature
sensor) harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between mass air flow sensor terminal 5 and
ground.

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connectors.

3.

CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between mass air flow sensor terminal 6 and ECM terminal 67.
Refer to Wiring Diagram.

4.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 4.

NG

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

4.

CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to

EC-192, "Component Inspection"

.

OK or NG

OK

>> GO TO 5.

NG

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

PBIB2625E

PBIB1565E

Voltage: Approximately 5V

PBIB1169E

Continuity should exist.

EC-192

< SERVICE INFORMATION >

[VQ35DE]

DTC P0112, P0113 IAT SENSOR

5.

CHECK INTERMITTENT INCIDENT

Refer to

EC-139

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326011

INTAKE AIR TEMPERATURE SENSOR

Check resistance between mass air flow sensor terminals 5 and 6 under the following conditions.

If NG, replace mass air flow sensor (with intake air temperature sen-
sor).

Removal and Installation

INFOID:0000000001326012

MASS AIR FLOW SENSOR

Refer to

EM-17

.

Intake air temperature

°

C (

°

F)

Resistance k

Ω

25 (77)

1.800 - 2.200

PBIB1604E

SEF012P