2011 INFINITI QX56 coolant temperature

P0116 ECT SENSOREC-215
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0116 ECT SENSOR
DTC LogicINFOID:0000000006288277
DTC DETECTION LOGIC
NOTE:
If DTC P0116 is displayed with P0117 or P0118,
first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-217, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TEST CONDITION:
Before performing the following procedure, do not add fuel.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and warm it up to normal operating temperature.
2. Rev engine up to 2,000 rpm for more than 10 minutes.
3. Move the vehicle to a cool place, then stop engine.
4. Check resistance between “fuel level s ensor unit and fuel pump” terminals 4 and 5.
5. Soak the vehicle until the resistance between “fuel level sensor unit and fuel pump” terminals 4 and 5
becomes 0.5 k Ω higher than the value measured before soaking.
CAUTION:
Never turn ignition sw itch ON during soaking.
NOTE:
Soak time changes depending on ambient ai r temperature. It may take several hours.
6. Start engine and let it idle for 20 minutes.
7. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-215, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288278
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-216, "
Component Inspection (Engine Coolant Temperature Sensor)".
Is the inspection result normal?
OK >> GO TO 2.
NG >> Replace engine coolant temperature sensor. Refer to EM-86, "
Exploded View".
2.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0116 ECT SEN/CIRC
(Engine coolant tempera-
ture sensor circuit range/
performance) Engine coolant temperature signal from engine
coolant temperature sensor does not fluctuate,
even when some time has passed after starting
the engine with pre-warming up condition.
 Harness or connectors
(High or low resistance in the circuit)
 Engine coolant temperature sensor
Revision: 2010 May2011 QX56

EC-216
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0116 ECT SENSOR
Component Inspection (Engine Coolant Temperature Sensor)
INFOID:0000000006288609
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature sensor harness connector.
3. Remove engine coolant temperature sensor.
4. Check resistance between engine coolant temperature sensor terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor. Refer to EM-86, "
Exploded View".
Terminals Condition Resistance (k Ω)
1 and 2 Temperature [ °C ( °F)] 20 (68) 2.35 - 2.73
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
JMBIA0080ZZ
Revision: 2010 May2011 QX56

P0117, P0118 ECT SENSOREC-217
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0117, P0118 ECT SENSOR
DTC LogicINFOID:0000000006217798
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-217, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217799
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature (ECT) sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between ECT sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
2.CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ECT sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0117 ECT SEN/CIRC
(Engine coolant tempera-
ture sensor circuit low input) An excessively low voltage from the sensor
is sent to ECM.
 Harness or connectors
(The engine coolant temperature sensor
circuit is open or shorted.)
 Engine coolant temperature sensor
P0118 ECT SEN/CIRC
(Engine coolant tempera-
ture sensor circuit high in-
put) An excessively high voltage from the sensor
is sent to ECM.
ECT sensor
Ground Voltage (V)
Connector Terminal
F21 1 Ground Approx. 5
ECT sensor ECM Continuity
Connector Terminal Connector Terminal
F 2 1 2 F 111 4 0 E x i s t e d
Revision: 2010 May2011 QX56

EC-218
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0117, P0118 ECT SENSOR
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-218, "
Component Inspection (Engine Coolant Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace engine coolant temperature sensor.
4.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Engine Coolant Temperature Sensor)INFOID:0000000006217800
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature sensor harness connector.
3. Remove engine coolant temperature sensor.
4. Check resistance between engine coolant temperature sensor terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor. Refer to EM-86, "
Exploded View".
Terminals Condition Resistance (k Ω)
1 and 2 Temperature [ °C ( °F)] 20 (68) 2.35 - 2.73
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
JMBIA0080ZZ
Revision: 2010 May2011 QX56

EC-222
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0125 ECT SENSOR
P0125 ECT SENSOR
DTC LogicINFOID:0000000006288280
DTC DETECTION LOGIC
NOTE:
If DTC P0125 is displayed with P0117 or P0118,
first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-217, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check that “COOLAN TEMP/S” is above 10 °C (50 °F).
WITH GST
Follow the procedure “With CONSULT-III” above.
Is the temperature above 10
°C (50°F)?
YES >> INSPECTION END
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Start engine and run it for 65 minutes at idle speed. If “COOLAN TEMP/S” increases to more than 10 °C (50 °F) within 65 minutes, stop engine because
the test result will be OK.
CAUTION:
Never overheat engine.
2. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> EC-222, "Diagnosis Procedure"
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288281
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-218, "
Component Inspection (Engine Coolant Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 2.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0125 ECT SENSOR
(Insufficient engine coolant
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
Revision: 2010 May2011 QX56

P0125 ECT SENSOREC-223
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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NO >> Replace engine coolant temperature sensor.
2.CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70 °C (158 °F)] condition, grasp lower radiator hose and confirm that the
engine coolant does not flow.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace thermostat. Refer to CO-20, "
Removal and Installation".
3.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Engine Coolant Temperature Sensor)INFOID:0000000006288610
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature sensor harness connector.
3. Remove engine coolant temperature sensor.
4. Check resistance between engine coolant temperature sensor
terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor. Refer to EM-86, "
Exploded View".
Terminals Condition Resistance (k Ω)
1 and 2 Temperature [ °C ( °F)] 20 (68) 2.35 - 2.73
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
JMBIA0080ZZ
Revision: 2010 May2011 QX56

EC-224
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0127 IAT SENSOR
P0127 IAT SENSOR
DTC LogicINFOID:0000000006288283
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
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.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Wait until engine coolant temperature is less than 90 °C (194 °F)
- Turn ignition switch ON.
- Select “DATA MONITOR” mode with CONSULT-III.
- Check the engine coolant temperature.
- If the engine coolant temperature is not less than 90 °C (194 °F), turn ignition switch OFF and cool down
engine.
NOTE:
Perform the following steps before engine coolant temperature is above 90 °C (194 °F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.
CAUTION:
Always drive vehicle at a safe speed.
6. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-224, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288284
1.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-225, "
Component Inspection (Intake Air Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace mass air flow sensor (with intake air temperature sensor).
2.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0127 IAT SENSOR-B1
(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 intake air temperature sensor
circuit is open or shorted)
 Intake air temperature sensor
Revision: 2010 May2011 QX56

EC-226
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0128 THERMOSTAT FUNCTION
P0128 THERMOSTAT FUNCTION
DTC LogicINFOID:0000000006288286
DTC DETECTION LOGIC
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301,
P0302, P0303, P0304, P0305, P0306, P0307 or P0308,
first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307,
P0308. Refer to EC-291, "
DTC Logic".
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leakage in the seal or the thermostat being stuck open.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
 For best results, perform at ambient temperature of –10 °C (14 °F) or higher.
 For best results, perform at en gine coolant temperature of –10 °C (14 °F) to 52 °C (126 °F).
 Before performing the following procedure, do not add fuel.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Turn A/C switch OFF.
2. Turn blower fan switch OFF.
3. Turn ignition switch ON.
4. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.
5. Check the indication of “COOLAN TEMP/S”. If it is below 52 °C (126 °F), go to next step.
If it is above 52 °C (126 °F), cool engine down to less than 52 °C (126 °F). Then go to next step.
6. Start engine and drive vehicle for 10 consec utive minutes under the following conditions.
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “COOLAN TEMP/S” increases to more than 71 °C (160 °F) within 10 minutes, turn ignition switch
OFF because the test result will be OK.
7. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-227, "Diagnosis Procedure".
NO >> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0128 THERMSTAT FNCTN
(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 thermostat
 Engine coolant temperature sensor
Vehicle speed More than 56 km/h (35 MPH)
Revision: 2010 May2011 QX56