2004 INFINITI FX35 coolant temperature

EC-198
[VQ35DE]
DTC P0125 ECT SENSOR
Revision: 2004 November 2004 FX35/FX45
DTC Confirmation ProcedureABS006NC
CAUTION:
Be careful not to overheat engine.
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. Check that “COOLAN TEMP/S” is above 10°C (50°F).
If it is above 10°C (50°F), the test result will be OK.
If it is below 10°C (50°F), go to following step.
4. Start engine and run it for 65 minutes at idle speed.
If “COOLAN TEMP/S” increases to more than 10°C (50°F)
within 65 minutes, stop engine because the test result will
be OK.
5. If DTC is detected, go to EC-198, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS00CH1
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 ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-199, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
SEF174Y
PBIB2195E

DTC P0125 ECT SENSOR
EC-199
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Revision: 2004 November 2004 FX35/FX45
3. CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70°C (158°F)] condition, grasp lower radiator hose and confirm the engine
coolant does not flow.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace thermostat. Refer to CO-26, "
WATER INLET AND THERMOSTAT ASSEMBLY"
.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-135, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-187, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionABS006NE
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 is measured between ECM terminal 73
(Engine coolant temperature sensor) and ground.
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationABS006NF
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-26, "WATER INLET AND THERMOSTAT ASSEMBLY" .
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

EC-200
[VQ35DE]
DTC P0127 IAT SENSOR
Revision: 2004 November 2004 FX35/FX45
DTC P0127 IAT SENSORPFP:22630
Component DescriptionABS006NG
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 LogicABS006NH
DTC Confirmation ProcedureABS006NI
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.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Wait until engine coolant temperature is less than 90°C (194°F)
a. Turn ignition switch ON.
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 name DTC detecting condition Possible cause
P0127
0127Intake air temperature
too highRationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor.

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

Intake air temperature sensor

DTC P0127 IAT SENSOR
EC-201
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
b. Select “DATA MONITOR” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90°C (194°F),
turn ignition switch OFF and cool down engine.

Perform the following steps before engine coolant tempera-
ture is above 90°C (194°F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con-
secutive seconds.
6. If 1st trip DTC is detected, go to EC-201, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS006NJ
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
Refer to EC-202, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3. CHECK INTERMITTENT INCIDENT
Refer to EC-135, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-182, "
Wiring Diagram" .
>>INSPECTION END
SEF189Y
PBIB2195E

DTC P0128 THERMOSTAT FUNCTION
EC-203
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
DTC P0128 THERMOSTAT FUNCTIONPFP:21200
On Board Diagnosis LogicABS006NM
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat stuck open.
DTC Confirmation ProcedureABS006NN
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.
TESTING CONDITION:

For best results, perform at ambient temperature of –10°C (14°F) or higher.

For best results, perform at engine coolant temperature of –10°C (14°F) to 60°C (140°F).
WITH CONSULT-II
1. Replace thermostat with new one. Refer to CO-26, "WATER INLET AND THERMOSTAT ASSEMBLY" .
Use only a genuine NISSAN thermostat as a replacement. If an incorrect thermostat is used, the MIL may
come on.
2. Turn ignition switch ON.
3. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with
CONSULT-II.
4. Check that the “COOLAN TEMP/S” is above 60°C (140°F).
If it is below 60°C (140°F), go to following step.
If it is above 60°C (140°F), cool down the engine to less than
60°C (140°F), then retry from step 1.
5. Drive vehicle for 10 consecutive minutes under the following
conditions.
If 1st trip DTC is detected, go to EC-203, "
Diagnostic Procedure"
.
WITH GST
1. Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS006NO
1. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-204, "
Component Inspection" .
OK or NG
OK >>INSPECTION END
NG >> Replace engine coolant temperature sensor.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128Thermostat functionThe engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough.

Thermostat

Leakage from sealing portion of thermo-
stat

Engine coolant temperature sensor
VHCL SPEED SE 80 - 120 km/h (50 - 75 MPH)
SEF176Y

EC-204
[VQ35DE]
DTC P0128 THERMOSTAT FUNCTION
Revision: 2004 November 2004 FX35/FX45
Component InspectionABS00D1K
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 is measured between ECM terminal 73
(Engine coolant temperature sensor) and ground.
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationABS006NQ
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-26, "WATER INLET AND THERMOSTAT ASSEMBLY" .
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

DTC P0181 FTT SENSOR
EC-273
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
DTC P0181 FTT SENSORPFP:22630
Component DescriptionABS006P6
The fuel tank temperature sensor is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a thermistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 107 (fuel tank
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 LogicABS006P7
DTC Confirmation ProcedureABS006P8
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 10 seconds.
If the result is NG, go to EC-276, "
Diagnostic Procedure" .
If the result is OK, go to following step.
4. Check “COOLAN TEMP/S” value.
If “COOLAN TEMP/S” is less than 60°C (140°F), the result will
be OK.
If “COOLAN TEMP/S” is above 60°C (140°F), go to the following
step.
5. Cool engine down until “COOLAN TEMP/S” is less than 60°C
(140°F).
6. Wait at least 10 seconds.
7. If 1st trip DTC is detected, go to EC-276, "
Diagnostic Procedure" .
PBIB1572E
Fluid temperature
°C (°F)Voltage*
VResistance
kΩ
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0181
0181Fuel tank temperature
sensor circuit range/
performanceRationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage sig-
nals from engine coolant temperature sensor
and intake air temperature sensor.

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

Fuel tank temperature sensor
SEF174Y

EC-292
[VQ35DE]
DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS-
FIRE
Revision: 2004 November 2004 FX35/FX45
WITH CONSULT-II
1. Turn ignition switch ON, and select “DATA MONITOR” mode
with CONSULT-II.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Restart engine and let it idle for about 15 minutes.
5. If 1st trip DTC is detected, go to EC-292, "
Diagnostic Procedure"
.
NOTE:
If 1st trip DTC is not detected during above procedure, performing
the following procedure is advised.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain
time. Refer to table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following condi-
tions should be satisfied at the same time.
The time to driving varies according to the engine speed in the freeze frame data.
Refer to the following table.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS006PU
1. CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
3. Check PCV hose connection.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2. CHECK FOR EXHAUST SYSTEM CLOGGING
Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace it.
PBIB0164E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) conditionWhen the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
Engine speed Time
Around 1,000 rpm Approximately 10 minutes
Around 2,000 rpm Approximately 5 minutes
More than 3,000 rpm Approximately 3.5 minutes