2006 INFINITI M35 engine coolant

EC-178
[VQ35DE]
DTC P0011, P0021 IVT CONTROL
Revision: 2006 January2006 M35/M45
DTC P0011, P0021 IVT CONTROLPFP:23796
DescriptionNBS004TT
SYSTEM DESCRIPTION
*: This signal is sent to the ECM through CAN communication line
This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing (IVT) control sole-
noid valve depending on driving status. This makes it possible to control the shut/open timing of the intake
valve to increase engine torque in low/mid speed range and output in high-speed range.
CONSULT-II Reference Value in Data Monitor ModeNBS004TU
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed and piston position
Intake valve
timing controlIntake valve timing control
solenoid valve Camshaft position sensor (PHASE)
Engine coolant temperature sensor Engine coolant temperature
Wheel sensor* Vehicle speed
PBIB3276E
MONITOR ITEM CONDITION SPECIFICATION
INT/V TIM (B1)
INT/V TIM (B2)
Engine: After warming up
Selector lever: P or N
Air conditioner switch: OFF
No loadIdle
5 - 5CA
When revving engine up to 2,000 rpm
quicklyApprox. 0
- 30CA
INT/V SOL (B1)
INT/V SOL (B2)
Engine: After warming up
Selector lever: P or N
Air conditioner switch: OFF
No loadIdle 0% - 2%
When revving engine up to 2,000 rpm
quicklyApprox. 0% - 50%

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-189
[VQ35DE]
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Revision: 2006 January2006 M35/M45
DTC P0037, P0038, P0057, P0058 HO2S2 HEATERPFP:226A0
DescriptionNBS004U8
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeNBS004U9
Specification data are reference values.
On Board Diagnosis LogicNBS004UA
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
Below 3,600 rpm after the following conditions are met.
Engine: After warming up
Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)
Engine speed: Below 3,600 rpm after the following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at
idle for 1 minute under no loadON
Engine speed: Above 3,600 rpm OFF
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0037
0037
(Bank 1)Heated oxygen
sensor 2 heater
control circuit lowThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)
Harness or connectors
(The heated oxygen sensor 2 heater circuit is
open or shorted.)
Heater oxygen sensor 2 heater P0057
0057
(Bank 2)
P0038
0038
(Bank 1)Heated oxygen
sensor 2 heater
control circuit highThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to
ECM through the heated oxygen sensor 2
heater.)
Harness or connectors
(The heated oxygen sensor 2 heater circuit is
shorted.)
Heater oxygen sensor 2 heater P0058
0058
(Bank 2)

EC-226
[VQ35DE]
DTC P0117, P0118 ECT SENSOR
Revision: 2006 January2006 M35/M45
DTC P0117, P0118 ECT SENSORPFP:22630
Component DescriptionNBS004VC
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 LogicNBS004VD
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 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
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 (104F)
More than approx. 4 minutes after ignition ON or START 80
C (176F)
Except as shown above40 - 80
C (104 - 176F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates
while engine is running.

DTC P0117, P0118 ECT SENSOR
EC-229
[VQ35DE]
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Revision: 2006 January2006 M35/M45
Diagnostic ProcedureNBS004VG
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 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.
1. Body ground M70 2. Body ground M16
PBIB2782E
PBIB1563E
Voltage: Approximately 5V
PBIB0080E

EC-230
[VQ35DE]
DTC P0117, P0118 ECT SENSOR
Revision: 2006 January2006 M35/M45
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-230, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace engine coolant temperature sensor.
5. CHECK INTERMITTENT INCIDENT
Refer to EC-165, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionNBS004VH
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 InstallationNBS004VI
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-31, "WATER OUTLET AND WATER PIPING" . Continuity should exist.
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-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]
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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