2006 INFINITI M35 engine

EC-232
[VQ35DE]
DTC P0122, P0123 TP SENSOR
Revision: 2006 January2006 M35/M45
DTC Confirmation ProcedureNBS004VM
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:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-234, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y

EC-234
[VQ35DE]
DTC P0122, P0123 TP SENSOR
Revision: 2006 January2006 M35/M45
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 ProcedureNBS004VO
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-172, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
47 LSensor power supply
(Throttle position sensor)[Ignition switch: ON]Approximately 5V
50 W Throttle position sensor 1[Ignition switch: ON]
Engine stopped
Selector lever: D
Accelerator pedal: Fully releasedMore than 0.36V
[Ignition switch: ON]
Engine stopped
Selector lever: D
Accelerator pedal: Fully depressedLess than 4.75V
66 BSensor ground
(Throttle position sensor)[Engine is running]
Warm-up condition
Idle speedApproximately 0V
69 R Throttle position sensor 2[Ignition switch: ON]
Engine stopped
Selector lever: D
Accelerator pedal: Fully releasedLess than 4.75V
[Ignition switch: ON]
Engine stopped
Selector lever: D
Accelerator pedal: Fully depressedMore than 0.36V
91 BRSensor power supply
(APP sensor 2)[Ignition switch: ON]Approximately 5V
1. Body ground M70 2. Body ground M16
PBIB2782E

EC-238
[VQ35DE]
DTC P0125 ECT SENSOR
Revision: 2006 January2006 M35/M45
DTC P0125 ECT SENSORPFP:22630
Component DescriptionNBS004VR
NOTE:
If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-226, "
DTC P0117, P0118 ECT SENSOR" .
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.

*: 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 LogicNBS004VS
This self-diagnosis has the one trip detection logic.
SEF594K
Engine coolant
temperature
C (F)Voltage* V Resistance k
–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
P0125
0125Insufficient engine cool-
ant temperature for
closed loop fuel control
Voltage sent to ECM from the sensor is not
practical, even when some time has passed
after starting the engine.
Engine coolant temperature is insufficient for
closed loop fuel control.
Harness or connectors
(High resistance in the circuit)
Engine coolant temperature sensor
Thermostat

DTC P0125 ECT SENSOR
EC-239
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2006 January2006 M35/M45
DTC Confirmation ProcedureNBS004VT
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 (50F).
If it is above 10
C (50F), the test result will be OK.
If it is below 10
C (50F), 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 (50F)
within 65 minutes, stop engine because the test result will
be OK.
5. If DTC is detected, go to EC-239, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureNBS004VU
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-172, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-240, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
SEF174Y
1. Body ground M70 2. Body ground M16
PBIB2782E

EC-240
[VQ35DE]
DTC P0125 ECT SENSOR
Revision: 2006 January2006 M35/M45
3. CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70
C (158F)] 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-29, "
WATER INLET AND THERMOSTAT ASSEMBLY"
.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-165, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-228, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionNBS004VV
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 InstallationNBS004VW
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-31, "WATER OUTLET AND WATER PIPING" .
PBIB2005E
TemperatureC (F) Resistance k
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P

DTC P0127 IAT SENSOR
EC-241
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2006 January2006 M35/M45
DTC P0127 IAT SENSORPFP:22630
Component DescriptionNBS004VX
The intake air temperature sensor is built-into mass air flow sensor
(1). 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 LogicNBS004VY
DTC Confirmation ProcedureNBS004VZ
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 90C (194F)
a. Turn ignition switch ON.
PBIA9559J
Intake air temperature
C (F)Voltage* V Resistance k
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
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

EC-242
[VQ35DE]
DTC P0127 IAT SENSOR
Revision: 2006 January2006 M35/M45
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 (194F),
turn ignition switch OFF and cool down engine.
Perform the following steps before engine coolant tempera-
ture is above 90
C (194F).
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-242, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureNBS004W0
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-172, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-243, "
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-165, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-223, "
Wiring Diagram" .
>>INSPECTION END
SEF189Y
1. Body ground M70 2. Body ground M16
PBIB2782E

EC-244
[VQ35DE]
DTC P0128 THERMOSTAT FUNCTION
Revision: 2006 January2006 M35/M45
DTC P0128 THERMOSTAT FUNCTIONPFP:21200
On Board Diagnosis LogicNBS004W3
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 ProcedureNBS004W4
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 –10C (14F) or higher.
For best results, perform at engine coolant temperature of –10C (14F) to 60C (140F).
WITH CONSULT-II
1. Replace thermostat with new one. Refer to CO-29, "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 (140F).
If it is below 60
C (140F), go to following step.
If it is above 60
C (140F), cool down the engine to less than
60
C (140F), 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-244, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureNBS004W5
1. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-245, "
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)
PBIB1917E