NISSAN LATIO 2010 Service Repair Manual

EC-696
< SERVICE INFORMATION >[MR18DE]
DTC P0125 ECT SENSOR
DTC P0125 ECT SENSOR
Component DescriptionINFOID:0000000005532524
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 elec trical resistance of the ther-
mistor decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 38 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doi ng 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:0000000005532525
NOTE:
• If DTC P0125 is displayed with P0117 or P0118, firs t perform the trouble diagnosis for DTC P0117 or P0118.
Refer to EC-687, "
DTC Confirmation Procedure".
• If DTC P0125 is displayed with P0116, first perform the trouble diagnosis for DTC P0116. Refer to EC-696,
"DTC Confirmation Procedure".
DTC Confirmation ProcedureINFOID:0000000005532526
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-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).
SEF594K
Engine coolant temperature
[° C ( °F)] Voltage* (V)
Resistance (kΩ)
–10 (14) 4.47.0 - 11.4
20 (68) 3.52.1 - 2.9
50 (122) 2.20.68 - 1.00
90 (194) 0.90.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0125
0125 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: January 20102010 Versa

DTC P0125 ECT SENSOREC-697
< SERVICE INFORMATION > [MR18DE]
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If it is above 10°
C (50°F), the test result will be OK.
If it is below 10 °C (50° F), 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 (50°F) within 65 minutes, stop engine because
the test result will be OK.
5. Check DTC.
6. If DTC is detected, go to EC-697, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005532527
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-638, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-698, "
Component Inspection".
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
3.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.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace thermostat. Refer to CO-46, "
Removal and Installation".
4.CHECK INTERMITTENT INCIDENT
Refer to EC-632
.
Refer to EC-688, "
Wiring Diagram".
>> INSPECTION END
:Vehicle front
1. Body ground E24 2. Engine ground F93. Engine ground F16
4. Body ground E15
BBIA0698E
Revision: January 20102010 Versa

EC-698
< SERVICE INFORMATION >[MR18DE]
DTC P0125 ECT SENSOR
Component Inspection
INFOID:0000000005532528
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 InstallationINFOID:0000000005532529
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-48, "Component".
PBIB2005E
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
Revision: January 20102010 Versa

DTC P0127 IAT SENSOREC-699
< SERVICE INFORMATION > [MR18DE]
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DTC P0127 IAT SENSOR
Component DescriptionINFOID:0000000005532530
The intake air temperature sensor is built-into mass air flow sensor
(1). The sensor detects intake air temperature and transmits a signal
to the ECM.
The temperature sensing unit uses a
thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

*: This data is reference value and is measured between ECM terminal 46 (Intake air
temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM te rminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000005532531
DTC Confirmation ProcedureINFOID:0000000005532532
CAUTION:
Always drive vehicle at a safe speed.
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.
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.
WITH CONSULT-III
1. Wait until engine coolant temperature is less than 96 °C (205 °F)
a. Turn ignition switch ON.
b. Select “DATA MONITOR” mode with CONSULT-III.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 96 °C (205° F), turn ignition switch OFF and cool down
engine.
• Perform the following steps before engine coolant temperature is above 96 °C (205° F).
PBIA9559J
Intake air temperature
[° C ( °F)] Voltage* (V)
Resistance (kΩ)
25 (77) 3.31.800 - 2.200
80 (176) 1.20.283 - 0.359
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127 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 temperature sensor circuit is open
or shorted)
• Intake air temperature sensor
Revision: January 20102010 Versa

EC-700
< SERVICE INFORMATION >[MR18DE]
DTC P0127 IAT SENSOR
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.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to
EC-700, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005532533
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-638, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-700, "
Component Inspection".
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3.CHECK INTERMITTENT INCIDENT
Refer to EC-632
.
Refer to EC-680, "
Wiring Diagram".
>> INSPECTION END
Component InspectionINFOID:0000000005532534
INTAKE AIR TEMPERATURE SENSOR
: Vehicle front
1. Body ground E24 2. Engine ground F93. Engine ground F16
4. Body ground E15
BBIA0698E
Revision: January 20102010 Versa

DTC P0127 IAT SENSOREC-701
< SERVICE INFORMATION > [MR18DE]
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1. Check resistance between mass air flow sensor (1) terminals 5
and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature sensor).
Removal and InstallationINFOID:0000000005532535
MASS AIR FLOW SENSOR
Refer to EM-135, "Removal and Installation".
Intake air temperature [° C (°F)] Resistance (k Ω)
25 (77) 1.800 - 2.200
PBIA9559J
SEF012P
Revision: January 20102010 Versa

EC-702
< SERVICE INFORMATION >[MR18DE]
DTC P0128 THERMOSTAT FUNCTION
DTC P0128 THERMOSTAT FUNCTION
On Board Diagn
osis LogicINFOID:0000000005532536
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P 0304, first perform the trouble
diagnosis for DTC P0300, P0301, P0302, P0303, P0304. Refer to EC-783, "
DTC Confirmation Proce-
dure".
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 stuck open.
DTC Confirmation ProcedureINFOID:0000000005532537
WITH CONSULT-III
CAUTION:
Always drive vehicle at a safe speed.
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.
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 53 °C (127 °F).
• Before performing the following procedure, do not fill with the fuel.
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 53 °C (127° F), go to following step.
If it is above 53 °C (127° F), cool down the engine to less than 53 °C (127° F). Then go to next steps.
6. Start engine.
7. Drive vehicle for 10 consecutive minutes under the following conditions.
If “COOLAN TEMP/S” increases to more than 75 °C (167° F) within 10 minutes, turn ignition switch
OFF because the test result will be OK.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-702, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005532538
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-703, "
Component Inspection".
OK or NG
OK >> GO TO 2.
NG >> Replace engine coolant temperature sensor.
2.CHECK THERMOSTAT
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128 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
VHCL SPEED SE
More than 56 km/h (35 MPH)
Revision: January 20102010 Versa

DTC P0128 THERMOSTAT FUNCTIONEC-703
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Refer to
CO-46, "Removal and Installation".
OK or NG
OK >> INSPECTION END
NG >> Replace thermostat.
Component InspectionINFOID:0000000005532539
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 InstallationINFOID:0000000005532540
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-48, "Component".
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
Revision: January 20102010 Versa

EC-704
< SERVICE INFORMATION >[MR18DE]
DTC P0130 A/F SENSOR 1
DTC P0130 A/F SENSOR 1
Component DescriptionINFOID:0000000005532541
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the
A/F sensor 1 is composed an elec-
trode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800° C
(1,472° F).
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000005532542
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000005532543
To judge the malfunction, the diagnosis c hecks that the A/F signal computed by ECM from the air fuel ratio (A/
F) sensor 1 signal fluctuates ac cording to fuel feedback control.
DTC Confirmation ProcedureINFOID:0000000005532544
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.
PROCEDURE FOR MALFUNCTION A
1. Start engine and warm it up to normal operating temperature.
PBIB3353E
PBIB3354E
Monitor itemConditionSpecification
A/F SEN1 (B1) • Engine: After warming upMaintaining engine speed at
2,000 rpm Fluctuates around 2.2 V
DTC No. Trouble diagnosis name
DTC detecting conditionPossible Cause
P0130
0130 Air fuel ratio (A/F) sensor 1
circuit A)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly in the range other
than approx. 2.2 V. • Harness or connectors
[Air fuel ratio (A/F) sensor 1 cir-
cuit is open or shorted.]
• Air fuel ratio (A/F) sensor 1
B) The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 2.2 V.
Revision: January 20102010 Versa

DTC P0130 A/F SENSOR 1EC-705
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2. Let engine idle for 2 minutes.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to
EC-707, "
Diagnosis Procedure".
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” in “DATA MONITOR” mode with CONSULT-III.
3. Check “A/F SEN1 (B1)” indication.
If the indication is constantly approx . 2.2 V and does not fluctuates, go to EC-707, "
Diagnosis Procedure".
If the indication fluctuates around 2.2 V, go to next step.
4. Select “A/F SEN1 (B1) P1276” (for DTC P0130) of “A/F SEN1” in “DTC WORK SUPPORT” mode with
CONSULT-III.
5. Touch “START”.
6. When the following conditions are met, “TESTIN G” will be displayed on the CONSULT-III screen.
If “TESTING” is not displayed after 20 seconds, retry from step 2.
7. Release accelerator pedal fully. NOTE:
Never apply brake during releasing the accelerator pedal.
8. Make sure that “TESTING” changes to “COMPLETED”. If “TESTING” changed to “OUT OF CONDITION”, retry from step 6.
9. Make sure that “OK” is display ed after touching “SELF-DIAG RESULT”.
If “NG” is displayed, go to EC-707, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000005532545
PROCEDURE MALFUNCTION B
Use this procedure to check the overall function of the A/F sensor 1 circuit. During this check, a 1st trip DTC
might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.
3. Set shift lever to D position with OD ON (A/T), D position (CVT) or 5th position (M/T), then release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30 MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
4. Repeat steps 2 and 3 for five times.
5. Stop the vehicle and turn ignition switch OFF.
6. Wait at least 10 seconds and restart engine.
7. Repeat steps 2 and 3 for five times.
8. Stop the vehicle and connect GST to the vehicle.
9. Make sure that no 1st trip DTC is displayed. If the 1st trip DTC is displayed, go to EC-707, "
Diagnosis Procedure".
ENG SPEED 1,000 - 3,200 rpm (A/T, CVT)
1,350 - 3,200 rpm (M/T)
VHCL SPEED SE More than 64 km/h (40 MPH)
B/FUEL SCHDL 1.0 - 8.0 msec
Shift lever D position with OD OFF (A/T)
D position (CVT)
5th position (M/T)
Revision: January 20102010 Versa