P0125 ECT SENSOREC-251
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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P0125 ECT SENSOR
DTC LogicINFOID:0000000009462204
DTC DETECTION LOGIC
NOTE:
• If DTC P0125 is displayed with P0 116, first perform the trouble diagnosis for DTC P0116. Refer to EC-
243, "DTC Logic".
• If DTC P0125 is displayed with P0117 or P0118, fi rst perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-245, "DTC Logic"
.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
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.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
With CONSULT
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode of “ENGINE” using CONSULT.
3. Check that “COOLAN TEMP/S” is above 10 °C (50 °F).
With GST
Follow the procedure “With CONSULT” above.
Is it above 5
°C (41°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.
2. Check 1st tip DTC.
If “COOLAN TEMP/S” indicatio n increases to more than 10°C (50 °F) within 65 minutes, stop engine
because the test resu lt will be OK.
CAUTION:
Be careful not to overheat engine.
With GST
Follow the procedure “With CONSULT” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-251, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462205
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
DTC No. CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0125 ECT SENSOR
(Insufficient coolant tempera-
ture 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
EC-252
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0125 ECT SENSOR
Check the engine coolant temperature sensor. Refer to
EC-244, "Component Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace engine coolant temperature sensor. Refer to CO-24, "Exploded View"
.
2.CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70 °C (158 °F)] condition, grasp lower radiator hose and confirm 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-22, "Removal and Installation"
.
Component InspectionINFOID:0000000009462206
1.CHECK ENGINE COOLANT TEMPERATURE (ECT) SENSOR
1. Turn ignition switch OFF.
2. Disconnect ECT sensor harness connector.
3. Remove ECT sensor.
4. Check resistance between ECT 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 CO-24, "Exploded View"
.
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
P0127 IAT SENSOREC-253
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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P0127 IAT SENSOR
DTC LogicINFOID:0000000009462207
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
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.
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 of “ENGINE” using 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 of “ENGINE” using 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-253, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462208
1.CHECK INTAKE AIR TEMPERATURE SENSOR
Check the intake air temperature sensor. Refer to EC-254, "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). Refer to EM-29, "Exploded
View".
DTC No.CONSULT screen terms
(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
(Intake air temperature sensor
circuit is open or shorted)
• Intake air temperature sensor
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0128 THERMOSTAT FUNCTIONEC-255
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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P0128 THERMOSTAT FUNCTION
DTC LogicINFOID:0000000009462210
DTC DETECTION LOGIC
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P0304, first perform the trouble
diagnosis for P0300, P0301, P 0302, P0303 or P0304. Refer to EC-318, "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-1
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-2
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-1
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. CONSULT screen terms
(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 – 58 °C (14 – 136 °F)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-256
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0128 THERMOSTAT FUNCTION
Drive the vehicle under the conditions instructed bel
ow until the difference between “COOLAN TEMP/S” and
“FUEL T/TMP SE” becomes at least 26 °C (47 °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 26 °C (47 °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-2
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-256, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462211
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Check the engine coolant temperature sensor. Refer to EC-256, "Component Inspection"
.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace engine coolant temperature sensor. Refer to CO-24, "Exploded View"
.
2.CHECK THERMOSTAT
Check the thermostat. Refer to CO-22, "Removal and Installation"
.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace thermostat.
Component InspectionINFOID:0000000009462212
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
COOLAN TEMP/S 66 °C (151 °F) or less
FUEL T/TMP SE Less than the value calculated by sub-
tracting 26 °C (47 °F) from “COOLAN
TEMP/S”.*
COOLAN TEMP/S FUEL T/TMP SE
70°C (158 °F) 44 °C ( 111 °F) or less
65 °C (149 °F) 39 °C (102 °F) or less
60 °C (140 °F) 34 °C (93 °F) or less
COOLAN TEMP/S 67 °C (153 °F) or more
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0128 THERMOSTAT FUNCTIONEC-257
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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 CO-24, "Exploded View"
.
Engine coolant tem-
perature sensor Condition Resistance (k Ω)
+ −
Te r m i n a l
12 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-302
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0181 FTT SENSOR
P0181 FTT SENSOR
DTC LogicINFOID:0000000009462238
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Is it necessary to erase permanent DTC?
YES >> GO TO 7.
NO >> GO TO 2.
2.PRECONDITIONING
If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-
dure 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 3.
3.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-1
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-304, "Diagnosis Procedure".
NO >> GO TO 4.
4.CHECK ENGINE COOLANT TEMPERATURE
With CONSULT
1. Select “COOLAN TEMP/S” in “DATA MONITOR” of “ENGINE” using CONSULT.
2. Check “COOLAN TEMP/S” value.
With GST
Follow the procedure “With CONSULT” above.
“
COOLAN TEMP/S” less than 60°C (140°F)?
YES >> INSPECTION END
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-2
With CONSULT
1. Cool engine down until “COOLAN TEMP/S” is less than 60 °C (140 °F).
DTC No. CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0181 FTT SENSOR
(Fuel temperature sensor ″A ″
circuit range/performance) A)
Rationally incorrect voltage from the
sensor is sent to ECM, compared with
the voltage signals from ECT sensor
and intake air temperature sensor. • Harness or connectors
(FTT sensor circuit is open or shorted)
• FTT sensor
• Combination meter
B) The comparison result of signals trans-
mitted to ECM from each temperature
sensor (IAT sensor, ECT sensor, EOT
sensor, and FTT sensor) shows that
the voltage signal of the FTT sensor is
higher/lower than that of other temper-
ature sensors when the engine is start-
ed with its cold state. • Harness or connectors
(High or low resistance in the FTT
sensor circuit)
• FTT sensor
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0300, P0301, P0302, P0303, P0304 MISFIRE
EC-319
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-2
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and drive the vehicle as per the similar conditions to (1st trip) Freeze Frame Data for a certain time. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
CAUTION:
Always drive vehicle in safe manner according to tr affic conditions and obey all traffic laws when
driving.
The time to driving varies according to the engine speed in the freeze frame data.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-319, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462256
1.CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
3. Check PCV hose connection.
Is intake air leak detected?
YES >> Discover air leak location and repair.
NO >> GO TO 2.
2.CHECK FOR EXHAUST SYSTEM CLOGGING
Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
Is the inspection result normal?
YES-1 >> With CONSULT: GO TO 3.
YES-2 >> Without CONSULT: GO TO 4.
NO >> Repair or replace it.
3.PERFORM POWER BALANCE TEST
With CONSULT
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode of “ENGINE” using CONSULT.
3. Make sure that each circuit produces a momentary engine speed drop.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 4.
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
Engine speed Time
Around 1,000 rpm Approximately 10 minutes
Around 2,000 rpm Approximately 5 minutes
More than 3,000 rpm Approximately 3.5 minutes
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM