2005 INFINITI FX35 engine

EC-930
[VK45DE]
DTC P0127 IAT SENSOR
Revision: 2005 July 2005 FX
DTC P0127 IAT SENSORPFP:22630
Component DescriptionABS007KL
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.

*: 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 LogicABS007KM
DTC Confirmation ProcedureABS007KN
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 k
Ω
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
0127 Intake air temperature
too high Rationally 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-931
[VK45DE]
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Revision: 2005 July 2005 FX
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-931, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS007KO
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-861, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-913, "
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-854, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-911, "
Wiring Diagram" .
>> INSPECTION END
SEF189Y
PBIB2195E

DTC P0128 THERMOSTAT FUNCTION EC-933
[VK45DE]
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Revision: 2005 July 2005 FX
DTC P0128 THERMOSTAT FUNCTIONPFP:21200
On Board Diagnosis LogicABS007KR
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 ProcedureABS007KS
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-53, "THERMOSTAT AND WATER CONTROL VALVE" .
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-933, "
Diagnostic Procedure" .
WITH GST
1. Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS007KT
1. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-934, "
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
0128 Thermostat function The 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)

EC-934
[VK45DE]
DTC P0128 THERMOSTAT FUNCTION
Revision: 2005 July 2005 FX
Component InspectionABS007KU
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

2. If NG, replace engine coolant temperature sensor.
Removal and InstallationABS007KV
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-53, "THERMOSTAT AND WATER CONTROL VALVE" .
PBIB2005E
Temperature °C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.0
90 (194) 0.236 - 0.260
SEF012P

DTC P0132, P0152 HO2S1 EC-935
[VK45DE]
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Revision: 2005 July 2005 FX
DTC P0132, P0152 HO2S1PFP:22690
Component DescriptionABS007KW
The heated oxygen sensor 1 is placed into the exhaust manifold. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 has a closed-end tube
made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions. The
heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts
the injection pulse duration to achieve the ideal air-fuel ratio. The
ideal air-fuel ratio occurs near the radical change from 1 to 0V.
CONSULT-II Reference Value in Data Monitor ModeABS007KX
Specification data are reference values.
On Board Diagnosis LogicABS007KY
To judge the malfunction, the diagnosis checks that the heated oxy-
gen sensor 1 output is not inordinately high.
SEF463R
SEF288D
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 (B1)
HO2S1 (B2)

Engine: After warming up Maintaining engine speed at 2,000 rpm 0 - 0.3V
←→ Approx. 0.6 -
1.0V
HO2S1 MNTR (B1)
HO2S1 MNTR (B2) LEAN
←→ RICH
Changes more than 5 times
during 10 seconds.
PBIB1847E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0132
0132
(Bank 1) Heated oxygen sensor
1 circuit high voltage An excessively high voltage from the sensor is
sent to ECM.

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

Heated oxygen sensor 1
P0152
0152
(Bank 2)

EC-936
[VK45DE]
DTC P0132, P0152 HO2S1
Revision: 2005 July 2005 FX
DTC Confirmation ProcedureABS007KZ
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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Select “DATA MONITOR” mode with CONSULT-II.
5. Restart engine and let it idle for 2 minutes.
6. If 1st trip DTC is detected, go to EC-940, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF174Y

EC-938
[VK45DE]
DTC P0132, P0152 HO2S1
Revision: 2005 July 2005 FX
Specification data are reference values and are measured between each terminal 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.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
16 R/L Heated oxygen sensor 1
(bank 1) [Engine is running]

Warm-up condition

Engine speed: 2,000 rpm 0 - Approximately 1.0V
(Periodically change)
78 B/R Sensor ground
(Heated oxygen sensor) [Engine is running]

Warm-up condition

Idle speed
Approximately 0V

EC-940
[VK45DE]
DTC P0132, P0152 HO2S1
Revision: 2005 July 2005 FX
Specification data are reference values and are measured between each terminal 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.
Diagnostic ProcedureABS007L1
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-861, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN HEATED OXYGEN SENSOR 1
1. Loosen and retighten corresponding heated oxygen sensor 1.
>> GO TO 3.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
35 BR Heated oxygen sensor 1
(bank 2) [Engine is running]

Warm-up condition

Engine speed:2,000 rpm 0 - Approximately 1.0V
(Periodically change)
78 B/R Sensor ground
(Heated oxygen sensor) [Engine is running]

Warm-up condition

Idle speed
Approximately 0V
PBIB2195E
Tightening torque: 50 N·m (5.1 kg-m, 37 ft-lb)
PBIB1520E