2006 INFINITI M35 engine

EC-952
[VK45DE]
DTC P0117, P0118 ECT SENSOR
Revision: 2006 January2006 M35/M45
3. DETECT MALFUNCTIONING RART
Check the following.
Harness connector F291, F50
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 F291, F50
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-953, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace engine coolant temperature sensor.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-878, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

DTC P0117, P0118 ECT SENSOR
EC-953
[VK45DE]
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Revision: 2006 January2006 M35/M45
Component InspectionNBS005CY
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 InstallationNBS005CZ
ENGINE COOLANT TEMPERATURE SENSOR
Refer to EM-233, "CYLINDER HEAD" .
PBIB2005E
TemperatureC (F) Resistance k
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P

EC-954
[VK45DE]
DTC P0122, P0123 TP SENSOR
Revision: 2006 January2006 M35/M45
DTC P0122, P0123 TP SENSORPFP:16119
Component DescriptionNBS005D0
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
CONSULT-II Reference Value in Data Monitor ModeNBS005D1
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagnosis LogicNBS005D2
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
THRTL SEN 1
THRTL SEN 2*
Ignition switch: ON
(Engine stopped)
Selector lever: DAccelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0122
0122Throttle position sensor
2 circuit low inputAn excessively low voltage from the TP sensor
2 is sent to ECM.
Harness or connectors
(TP sensor 2 circuit is open or shorted.)
(APP sensor 2 circuit is shorted.)
Electric throttle control actuator
(TP sensor 2)
Accelerator pedal position sensor
(APP sensor 2) P0123
0123Throttle position sensor
2 circuit high inputAn excessively high voltage from the TP sen-
sor 2 is sent to ECM.
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

DTC P0122, P0123 TP SENSOR
EC-955
[VK45DE]
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Revision: 2006 January2006 M35/M45
DTC Confirmation ProcedureNBS005D3
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-957, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y

DTC P0122, P0123 TP SENSOR
EC-957
[VK45DE]
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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 ProcedureNBS005D5
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-885, "
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

DTC P0125 ECT SENSOR
EC-961
[VK45DE]
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Revision: 2006 January2006 M35/M45
DTC P0125 ECT SENSORPFP:22630
Component DescriptionNBS005D8
NOTE:
If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-948
.
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 dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicNBS005D9
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

EC-962
[VK45DE]
DTC P0125 ECT SENSOR
Revision: 2006 January2006 M35/M45
DTC Confirmation ProcedureNBS005DA
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-962, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureNBS005DB
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-885, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-963, "
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

DTC P0125 ECT SENSOR
EC-963
[VK45DE]
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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-55, "
THERMOSTAT AND WATER CONTROL VALVE" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-878, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-950, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionNBS005DC
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 InstallationNBS005DD
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-55, "THERMOSTAT AND WATER CONTROL VALVE" .
PBIB2005E
TemperatureC (F) Resistance k
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P