EC-742
< DTC/CIRCUIT DIAGNOSIS >[VQ35DE]
P0117, P0118 ECT SENSOR
P0117, P0118 ECT SENSOR
DTC LogicINFOID:0000000009462609
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next test.
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 >> Proceed to EC-742, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462610
1.CHECK ECT SENSOR POWER SUPPLY
1. Disconnect engine coolant temperatur e (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
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ECT sensor harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
DTC No. Trouble Diagnosis
Name DTC detecting condition Possible Cause
P0117 Engine coolant tem-
perature sensor cir-
cuit low input An 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 Engine coolant tem-
perature sensor cir-
cuit high input An excessively high voltage from the sensor is
sent to ECM.
ECT sensor Ground Voltage
Connector Terminal
F11 1 Ground Approx. 5 V
ECT sensor ECM Continuity
Connector Terminal Connector Terminal
F11 2 F79 76 Existed
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0117, P0118 ECT SENSOREC-743
< DTC/CIRCUIT DIAGNOSIS > [VQ35DE]
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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
Check engine coolant temperature sensor. Refer to EC-743, "Component Inspection"
.
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-43, "Intermittent Incident".
NO >> Replace engine coolant temperature sensor. Refer to CO-51, "Removal and Installation"
.
Component InspectionINFOID:0000000009462611
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. Refer to CO-51, "Removal and Installation"
.
4. Check resistance between engine coolant temperature sensor terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor. Refer to CO-51, "Removal and Installation"
.
ECT sensor
ConditionResistance
(kΩ)
+
−
Te r m i n a l
1 2 Temperature [ °C ( °F)] 20 (68) 2.37 - 2.63
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
JMBIA0080ZZ
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-746
< DTC/CIRCUIT DIAGNOSIS >[VQ35DE]
P0125 ECT SENSOR
P0125 ECT SENSOR
DTC LogicINFOID:0000000009462615
DTC DETECTION LOGIC
NOTE:
• If DTC P0125 is displayed with P0116, first perfo rm the trouble diagnosis for DTC P0116. Refer to EC-
740, "DTC Logic".
• If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-742, "DTC Logic"
.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next test.
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
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT.
3. Check that “COOLAN TEMP/S” is above 10 °C (50 °F).
With GST
Follow the procedure “With CONSULT” above.
Is the temperature above 10
°C (50°F)?
YES >> INSPECTION END
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT
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” above.
Is 1st trip DTC detected?
YES >> EC-746, "Diagnosis Procedure"
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462616
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Check engine coolant temperature sensor. Refer to EC-747, "Component Inspection"
.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0125 Insufficient 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
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0125 ECT SENSOREC-747
< DTC/CIRCUIT DIAGNOSIS > [VQ35DE]
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Is the inspection result normal?
YES >> GO TO 2.
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 >> Check intermittent incident. Refer to GI-43, "Intermittent Incident".
NO >> Repair or replace thermostat. Refer to CO-49, "Removal and Installation"
.
Component InspectionINFOID:0000000009462617
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. Refer to CO-51, "Removal and Installation"
.
4. Check resistance between engine coolant temperature sensor terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor. Refer to CO-51, "Removal and Installation"
.
ECT sensor
ConditionResistance
(kΩ)
+
−
Te r m i n a l
1 2 Temperature [ °C ( °F)] 20 (68) 2.37 - 2.63
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
JMBIA0080ZZ
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-748
< DTC/CIRCUIT DIAGNOSIS >[VQ35DE]
P0127 IAT SENSOR
P0127 IAT SENSOR
DTC LogicINFOID:0000000009462618
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next test.
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
1. Wait until engine coolant temperature is less than 96 °C (205 °F)
- Turn ignition switch ON.
- Select “DATA MONITOR” mode with CONSULT.
- Check the engine coolant temperature.
- If the engine coolant temperature is not less than 96 °C (205 °F), turn ignition switch OFF and cool down
engine.
NOTE:
Perform the following steps before engine coolant temperature is above 96 °C (205 °F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT.
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” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-748, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462619
1.CHECK INTAKE AIR TEMPERATURE SENSOR
Check intake air temperature sensor. Refer to EC-749, "Component Inspection"
.
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-43, "Intermittent Incident".
NO >> Replace mass air flow sensor (with intake air temperature sensor).
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127 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 sensor circuit is open or shorted)
• Intake air temperature sensor
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-750
< DTC/CIRCUIT DIAGNOSIS >[VQ35DE]
P0128 THERMOSTAT FUNCTION
P0128 THERMOSTAT FUNCTION
DTC LogicINFOID:0000000009462621
DTC DETECTION LOGIC
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305 or P0306, first perform
the trouble diagnosis for P0300, P0301, P0302, P0303, P 0304, P0305, P0306. Refer to EC-809, "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 leak in the seal or the thermostat being stuck open.
DTC CONFIRMATION PROCEDURE
NOTE:
Never refuel before and during the following procedure.
1.PRECONDITIONING-I
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
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.PRECONDITIONING-II
With CONSULT
1. Turn ignition switch ON.
2. Check the following conditions:
3. Select “DATA MONITOR” mode of “ENGINE” using CONSULT.
4. Check the following conditions:
Is the condition satisfied?
YES >> GO TO 3.
NO >> 1. Satisfy the condition.
2. GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-I
With CONSULT
1. Start engine.
2. Drive the vehicle until the following condition is satisfied.
CAUTION:
Always drive vehicle at safe speed.
- STEP 1
DTC No. Trouble diagnosis
(Trouble diagnosis content) DTC detecting condition Possible cause
P0128 THERMSTAT FNCTN
[Coolant thermostat (coolant
temperature below thermostat
regulating temperature)] The engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough. •Thermostat
• Leakage from sealing portion of ther-
mostat
• Engine coolant temperature sensor
Ambient temperature −10 °C (14 °F) or more
A/C switch OFF
Blower fan switch OFF
COOLAN TEMP/S −10 °C – 46 °C (14 – 115 °F)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0128 THERMOSTAT FUNCTIONEC-751
< DTC/CIRCUIT DIAGNOSIS > [VQ35DE]
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Drive the vehicle under the conditions instructed bel
ow until the difference between “COOLAN TEMP/S” and
“FUEL T/TMP SE” becomes at least 24 °C (43 °F).
*: Example
- STEP 2
Drive the vehicle at 50 km/h (32 MPH) or more with the difference between “COOLAN TEMP/S” and “FUEL
T/TMP SE” maintained at 24 °C (43 °F) or more.
NOTE:
Keep the accelerator pedal as steady as possible during cruising.
- STEP 3
Drive the vehicle at 50 km/h (32 MPH) or more until “COOLAN TEMP/S” increases by 6 °C (11 °F).
NOTE:
Keep the accelerator pedal as steady as possible during cruising.
Is the condition satisfied?
YES >> GO TO 4.
NO >> GO TO 1.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
With CONSULT
1. Drive the vehicle until the following condition is satisfied.
CAUTION:
Always drive vehicle at safe speed.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-751, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462622
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Check engine coolant temperature sensor. Refer to EC-751, "Component Inspection"
.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace engine coolant temperature sensor.
2.CHECK THERMOSTAT
Check thermostat. Refer to CO-49, "Removal and Installation"
.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace thermostat. Refer to CO-49, "Removal and Installation"
.
Component InspectionINFOID:0000000009462623
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
COOLAN TEMP/S 65 °C (149 °F) or less
FUEL T/TMP SE Less than the value calculated by sub- tracting 24°C (43 °F) from “COOLAN
TEMP/S”.*
COOLAN TEMP/S FUEL T/TMP SE
70°C (158 °F) 46 °C (115 °F) or less
65 °C (149 °F) 41 °C (106 °F) or less
60 °C (140 °F) 36 °C (97 °F) or less
COOLAN TEMP/S 65 °C (149 °F) or more
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-752
< DTC/CIRCUIT DIAGNOSIS >[VQ35DE]
P0128 THERMOSTAT FUNCTION
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature sensor harness connector.
3. Remove engine coolant temperature sensor. Refer to CO-51, "Removal and Installation"
.
4. Check resistance between engine coolant temperature sensor
terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor. Refer to CO-51, "Removal and Installation"
.
ECT sensor
ConditionResistance
(kΩ)
+
−
Te r m i n a l
1 2 Temperature [ °C ( °F)] 20 (68) 2.37 - 2.63
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
JMBIA0080ZZ
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM