2004 INFINITI FX35 Temperature sensor

DTC P0102, P0103 MAF SENSOR
EC-173
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
DTC P0102, P0103 MAF SENSORPFP:22680
Component DescriptionABS006M8
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, electric current is supplied to hot wire is changed to main-
tain the temperature of the hot wire as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor ModeABS006M9
Specification data are reference values.
On Board Diagnosis LogicABS006MA
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.
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-131, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE

Engine: After warming up

Shift lever: P or N

Air conditioner switch: OFF

No-loadIdle 5% - 35%
2,500 rpm 5% - 35%
MASS AIRFLOW

Engine: After warming up

Shift lever: P or N

Air conditioner switch: OFF

No-loadIdle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0102
0102Mass air flow sensor
circuit low inputAn excessively low voltage from the sensor is
sent to ECM.

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

Intake air leaks

Mass air flow sensor
P0103
0103Mass air flow sensor
circuit high inputAn excessively high voltage from the sensor is
sent to ECM.

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

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.

DTC P0102, P0103 MAF SENSOR
EC-179
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Revision: 2004 November 2004 FX35/FX45
Component InspectionABS006ME
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 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.

Turn ignition switch OFF.

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

Perform steps 2 and 3 again.
5. If NG, remove mass air flow sensor from air duct. Check hot wire for damage or dust.
6. If NG, clean or replace mass air flow sensor.
Removal and InstallationABS006MF
MASS AIR FLOW SENSOR
Refer to EM-17, "AIR CLEANER AND AIR DUCT" .
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-180
[VQ35DE]
DTC P0112, P0113 IAT SENSOR
Revision: 2004 November 2004 FX35/FX45
DTC P0112, P0113 IAT SENSORPFP:22630
Component DescriptionABS006MG
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.

*: 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 LogicABS006MH
DTC Confirmation ProcedureABS006MI
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-183, "
Diagnostic Procedure"
.
PBIB1604E
Intake air temperature
°C (°F)Voltage* V Resistance kΩ
25 (77) 3.32 1.94 - 2.06
80 (176) 1.23 0.295 - 0.349
SEF012P
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0112
0112Intake air tempera-
ture sensor circuit
low inputAn 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
0113Intake air tempera-
ture sensor circuit
high inputAn excessively high voltage from the sensor is
sent to ECM.
SEF058Y

DTC P0112, P0113 IAT SENSOR
EC-183
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Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00CGR
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-141, "
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) 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.
PBIB2195E
PBIB1565E
Voltage: Approximately 5V
PBIB1169E
Continuity should exist.

EC-184
[VQ35DE]
DTC P0112, P0113 IAT SENSOR
Revision: 2004 November 2004 FX35/FX45
4. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-184, "
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-135, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionABS006ML
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between mass air flow sensor terminals 5 and
6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and InstallationABS006MM
MASS AIR FLOW SENSOR
Refer to EM-17, "AIR CLEANER AND AIR DUCT" .
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.94 - 2.06
PBIB1604E
SEF012P

DTC P0117, P0118 ECT SENSOR
EC-185
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
DTC P0117, P0118 ECT SENSORPFP:22630
Component DescriptionABS006MN
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.

*: This data is reference value and is 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 damage to the ECM's transistor. Use a ground other than ECM termi-
nals, such as the ground.
On Board Diagnosis LogicABS006MO
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 kΩ
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
NameDTC Detecting Condition Possible Cause
P0117
0117Engine coolant tem-
perature sensor cir-
cuit low inputAn 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
0118Engine coolant tem-
perature sensor cir-
cuit high inputAn excessively high voltage from the sensor is
sent to ECM.
Detected items Engine operating condition in fail-safe mode
Engine coolant temper-
ature sensor circuitEngine 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.
ConditionEngine 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
START80°C (176°F)
Except as shown above40 - 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.

EC-188
[VQ35DE]
DTC P0117, P0118 ECT SENSOR
Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00CGS
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-141, "
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 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
PBIB2195E
PBIB1563E
Voltage: Approximately 5V
PBIB0080E

DTC P0117, P0118 ECT SENSOR
EC-189
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Revision: 2004 November 2004 FX35/FX45
3. 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 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-189, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace engine coolant temperature sensor.
5. CHECK INTERMITTENT INCIDENT
Refer to EC-135, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionABS006MS
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

*: This data is reference value and are measured between ECM terminal 73
(Engine coolant temperature sensor) and ground.
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationABS006MT
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-26, "WATER INLET AND THERMOSTAT ASSEMBLY" . Continuity should exist.
PBIB2005E
Engine coolant
temperature°C (°F)Voltage* V Resistance kΩ
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