INFINITI FX35 2007 Service Manual

DTC P0112, P0113 IAT SENSOR EC-875
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Revision: 2006 July 2007 FX35/FX45
DTC P0112, P0113 IAT SENSORPFP:22630
Component DescriptionNBS0043T
The intake air temperature 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>
*: These data are reference values and are 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 LogicNBS0043U
DTC Confirmation ProcedureNBS0043V
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-878, "
Diagnostic Procedure"
.
PBIB1604E
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 tempera-
ture sensor circuit
low input An excessively low voltage from the sensor is
sent to ECM.

Harness or connectors
(The 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.
SEF058Y

EC-876
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DTC P0112, P0113 IAT SENSOR
Revision: 2006 July 2007 FX35/FX45
WITH GST
Follow the procedure “WITH CONSULT-II” above.

DTC P0112, P0113 IAT SENSOR EC-877
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Revision: 2006 July 2007 FX35/FX45
Wiring DiagramNBS0043W
TBWM0723E

EC-878
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DTC P0112, P0113 IAT SENSOR
Revision: 2006 July 2007 FX35/FX45
Diagnostic ProcedureNBS0043X
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-819, "
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 (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.
PBIB2195E
PBIB3230E
Voltage: Approximately 5V
PBIB1169E

DTC P0112, P0113 IAT SENSOR EC-879
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Revision: 2006 July 2007 FX35/FX45
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-879, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
5. CHECK INTERMITTENT INCIDENT
Refer to EC-812, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionNBS0043Y
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature terminals 5
and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature sensor).
Removal and InstallationNBS0043Z
MASS AIR FLOW SENSOR
Refer to EM-177, "AIR CLEANER AND AIR DUCT" .
Continuity should exist.
Intake air temperature
°C ( °F) Resistance k Ω
25 (77) 1.800 - 2.200
PBIB1604E
SEF012P

EC-880
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DTC P0117, P0118 ECT SENSOR
Revision: 2006 July 2007 FX35/FX45
DTC P0117, P0118 ECT SENSORPFP:22630
Component DescriptionNBS00440
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.
<Reference data>
*: These data are reference values and are measured between ECM terminal 73
(Engine coolant temperature sensor) 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.
On Board Diagnosis LogicNBS00441
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.
SEF594K
Engine coolant temperature
° C ( °F) Voltage* V Resistance k
Ω
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble Diagnosis
Name DTC Detecting Condition Possible Cause
P0117
0117 Engine coolant tem-
perature sensor cir-
cuit low input An excessively low voltage from the sensor is
sent to ECM.

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

Engine coolant temperature sensor
P0118
0118 Engine coolant tem-
perature sensor cir-
cuit high input An excessively high voltage from the sensor is
sent to ECM.
Detected items Engine operating condition in fail-safe mode
Engine coolant temper- ature sensor circuit Engine coolant temperature will be determined by ECM based on the time after turning ignition switch ON
or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned ON or START 40 °C (104 °F)
More than approx. 4 minutes after ignition ON or START 80 °C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates
while engine is running.

DTC P0117, P0118 ECT SENSOR EC-881
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Revision: 2006 July 2007 FX35/FX45
DTC Confirmation ProcedureNBS00442
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 DTC is detected, go to EC-883, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y

EC-882
[VK45DE]
DTC P0117, P0118 ECT SENSOR
Revision: 2006 July 2007 FX35/FX45
Wiring DiagramNBS00443
TBWM1328E

DTC P0117, P0118 ECT SENSOR EC-883
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Revision: 2006 July 2007 FX35/FX45
Diagnostic ProcedureNBS00444
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-819, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ECT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature (ECT) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between ECT sensor terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
PBIB2195E
: Vehicle front 1. Engine coolant temperature sensor 2. Engine coolant temperature sensor
sub-harness connector
Voltage: Approximately 5V
PBIB3231E
PBIB0080E

EC-884
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DTC P0117, P0118 ECT SENSOR
Revision: 2006 July 2007 FX35/FX45
3. DETECT MALFUNCTIONING RART
Check the following.

Harness connector F261, F24

Harness for open or short between ECM and engine coolant temperature sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT sensor terminal 2 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 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connector F261, F24

Harness for open and short between ECT sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-885, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace engine coolant temperature sensor.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-812, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.