2008 INFINITI FX35 Coolant Temperature Sensor

EC-124
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
VHCL SPD CUTNON/
CUT  Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the ASCD set
speed.
CUT: Vehicle speed increased to excessively high
compared with the ASCD set speed, and ASCD op-
eration is cut off.
LO SPEED CUT NON/
CUT  Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the ASCD set
speed.
CUT: Vehicle speed decreased to excessively low
compared with the ASCD set speed, and ASCD op-
eration is cut off.
AT OD MONITOR ON/OFF  Indicates [ON/OFF] condition of A/T O/D according
to the input signal from the TCM.
AT OD CANCEL ON/OFF  Indicates [ON/OFF] condition of A/T O/D cancel
signal sent from the TCM.
DIST SW ON/OFF  Indicates [ON/OFF] condition from DISTANCE
switch signal.
CRUISE LAMP ON/OFF  Indicates [ON/OFF] condition of CRUISE lamp de-
termined by the ECM according to the input signals.
SET LAMP ON/OFF  Indicates [ON/OFF] condition of SET lamp deter-
mined by the ECM according to the input signals.
A/F ADJ-B1 —  Indicates the correction of factor stored in ECM. The factor is calculated from the difference be-
tween the target air-fuel ratio stored in ECM and the
air-fuel ratio calculated from A/F sensor 1 signal.
A/F ADJ-B2

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Monitored item Unit Description Remarks
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION  Engine: Return to the original
trouble condition
 Change the amount of fuel injec- tion using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Harness and connectors
 Fuel injector
 Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING  Engine: Return to the original
trouble condition
 Timing light: Set
 Retard the ignition timing using
CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Perform Idle Air Volume Learning.
POWER BAL-
ANCE  Engine: After warming up, idle the
engine.
 A/C switch: OFF
 Selector lever: P or N
 Cut off each fuel injector signal one at a time using CONSULT-III. Engine runs rough or dies.
 Harness and connectors
 Compression
 Fuel injector
 Power transistor
Spark plug
 Ignition coil
COOLING FAN* Ignition switch: ON
 Turn the cooling fan “HI”, “MID”,
“LOW” and “OFF” using CON-
SULT-III. Cooling fan moves and stops.
 Harness and connectors
 Cooling fan motor
 IPDM E/R
ENG COOLANT
TEMP  Engine: Return to the original
trouble condition
 Change the engine coolant tem-
perature using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.  Harness and connectors
 Engine coolant temperature sen-
sor
 Fuel injector
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-131
< SERVICE INFORMATION > [VQ35DE]
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TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000001325940
The specification (SP) value indicates the tolerance of
the value that is displayed in “SPEC” of “DATA MONI-
TOR” mode of CONSULT-III during normal operation of the Engine Control System. When the value in “SPEC”
of “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When the
value in “SPEC” of “DATA MONITOR” mode is NOT withi n the SP value, the Engine Control System may have
one or more malfunctions.
The SP value is used to detect malfunctions that may af fect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
 B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board correc- tion)
 A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
 MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionINFOID:0000000001325941
 Vehicle driven distance: More than 5,000 km (3,107 miles)
 Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2, 14.25 - 15.12 psi)
 Atmospheric temperature: 20 - 30 °C (68 - 86 °F)
 Engine coolant temperature: 75 - 95 °C (167 - 203 °F)
 Transmission: Warmed-up
- After the engine is warmed up to normal operating temperat ure, drive vehicle until “ATF TEMP 1” (A/T fluid
temperature sensor signal) indicates more than 60 °C (140 °F).
 Electrical load: Not applied
- Rear window defogger switch, air conditioner switch, li ghting switch are OFF. Steering wheel is straight
ahead.
 Engine speed: Idle
Inspection ProcedureINFOID:0000000001325942
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-80, "
Basic Inspection".
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2” and “MAS A/F SE-B1” in “SPEC” of “DATA
MONITOR” mode with CONSULT-III.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-131, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001325943
OVERALL SEQUENCE
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DTC P0011, P0021 IVT CONTROL
EC-149
< SERVICE INFORMATION > [VQ35DE]
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DTC P0011, P0021 IVT CONTROL
DescriptionINFOID:0000000001325958
SYSTEM DESCRIPTION
*: This signal is sent to the ECM through CAN communication line
This mechanism hydraulically controls cam phases c
ontinuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft posit ion, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing control solenoid
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-III Reference Val ue in Data Monitor ModeINFOID:0000000001325959
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 load Idle
−5° - 5 °CA
When revving engine up to 2,000 rpm
quickly Approx. 0
° - 30 °CA
INT/V SOL(B1)
INT/V SOL(B2)  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
 No load Idle 0% - 2%
When revving engine up to 2,000 rpm
quickly
Approx. 0% - 50%
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EC-160
< SERVICE INFORMATION >[VQ35DE]
DTC P0037, P
0038, P0057, P0058 HO2S2 HEATER
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DescriptionINFOID:0000000001325973
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxy gen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001325974
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001325975
DTC Confirmation ProcedureINFOID:0000000001325976
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
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 3,600 OFF
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 load ON
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 load ON
 Engine speed: Above 3,600 rpm OFF
DTC No. Trouble diagnosis
name DTC detecting condition Possible cause
P0037
0037
(Bank 1) Heated oxygen
sensor 2 heater
control circuit low The 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
(Heated oxygen sensor 2 heater circuit is
open or shorted.)
 Heated oxygen sensor 2 heater
P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen
sensor 2 heater
control circuit high The 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
(Heated oxygen sensor 2 heater circuit is
shorted.)
 Heated oxygen sensor 2 heater
P0058
0058
(Bank 2)
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DTC P0117, P0118 ECT SENSOREC-193
< SERVICE INFORMATION > [VQ35DE]
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DTC P0117, P0118 ECT SENSOR
Component DescriptionINFOID:0000000001326013
The engine coolant temperature (ECT
) 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 sens or 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 values and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000001326014
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
Ω
-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 Condit
ion Possible Cause
P0117
0117 Engine coolant tem-
perature sensor cir-
cuit low input An excessively low voltage from the sensor is
sent to ECM.
 Harness or connectors
(Engine coolant temperature sensor circuit is
open or shorted.)
 Engine coolant temperature sensor
P0118
0118 Engine coolant tem-
perature sensor cir-
cuit high input An excessively high voltage from the sensor is
sent to ECM.
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EC-194
< SERVICE INFORMATION >[VQ35DE]
DTC P0117, P0118 ECT SENSOR
DTC Confirmation Procedure
INFOID:0000000001326015
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check DTC.
3. If DTC is detected, go to EC-195, "
Diagnosis Procedure".
Detected items Engine operating condition in fail-safe mode
Engine coolant temper- ature sensor circuit Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT-III displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-III display)
Just as ignition switch is turned ON or START 40 °C (104 °F)
Approx. 4 minutes or more after engine starting 80 °C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates while
engine is running.
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EC-196
< SERVICE INFORMATION >[VQ35DE]
DTC P0117, P0118 ECT SENSOR
2. Loosen and retighten ground screw on the body. Refer to
EC-144, "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-III 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.
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 s ensor 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-197, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace engine coolant temperature sensor.
PBIB2625E
PBIB1563E
Voltage: Approximately 5V
PBIB0080E
Continuity should exist.
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DTC P0117, P0118 ECT SENSOREC-197
< SERVICE INFORMATION > [VQ35DE]
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5.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326018
ENGINE COOLANT TEMPERATURE SENSOR
Check resistance between engine cool ant temperature sensor termi-
nals 1 and 2 as shown in the figure.

If NG, replace engine coolant temperature sensor.
Removal and InstallationINFOID:0000000001326019
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-27.
PBIB2005E
Engine coolant temperature °C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
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