NISSAN LATIO 2007 Service Repair Manual

EC-212Revision: June 2006
DTC P0125 ECT SENSOR
2007 Versa
DTC P0125 ECT SENSORPFP:22630
DescriptionUBS00QE4
NOTE:
If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-200, "
DTC P0117, P0118 ECT SENSOR" .
COMPONENT DESCRIPTION
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 electrical resistance of the ther-
mistor decreases as temperature increases.
< Reference data>
*: This data is reference values 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. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicUBS00QE5
This self-diagnosis ha one trip detection logic.
SEF 5 94 K
Engine coolant
temperature°C (°F)Voltage* V Resistance kΩ
−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
SEF 0 12 P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0125
0125Insufficient 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

DTC P0125 ECT SENSOR
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DTC Confirmation ProcedureUBS00QE6
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-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Check that “COOLAN TEMP/S” is above 10°C (50°F).
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. If DTC is detected, go to EC-213, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00QE7
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-214, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
SEF 0 58 Y
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15
BBIA0698E

EC-214Revision: June 2006
DTC P0125 ECT SENSOR
2007 Versa
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-18, "
THERMOSTAT" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-143, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-202, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionUBS00QE8
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.
<Reference data>
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationUBS00QE9
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-18, "THERMOSTAT"
PBIB2005E
Engine coolant temperature°C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF 0 12 P

DTC P0127 IAT SENSOR
EC-215
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Revision: June 20062007 Versa
DTC P0127 IAT SENSORPFP:22630
Component DescriptionUBS00QEA
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.
<Reference data>
*: 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 terminals, such as the ground.
On Board Diagnosis LogicUBS00QEB
PBIA9559J
Intake air temperature
°C (°F)Voltage* V Resistance K.Ω
25 (77) 3.3 1.800 - 2.200
80 (176) 1.2 0.283 - 0.359
SEF 0 12 P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127Intake air temperature
too highRationally 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

EC-216Revision: June 2006
DTC P0127 IAT SENSOR
2007 Versa
DTC Confirmation ProcedureUBS00QEC
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-II
1. Wait until engine coolant temperature is less than 90°C (194°F)
a. Turn ignition switch ON.
b. Select “DATA MONITOR” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90°C (194°F),
turn ignition switch OFF and cool down engine.

Perform the following steps before engine coolant tempera-
ture is above 90°C (194°F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con-
secutive seconds.
6. If 1st trip DTC is detected, go to EC-216, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II” above.
Diagnostic ProcedureUBS00QED
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
SEF 1 89 Y
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15
BBIA0698E

DTC P0127 IAT SENSOR
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2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-217, "
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-143, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-197, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionUBS00QEE
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature sensor (1) ter-
minals 5 and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and InstallationUBS00QEF
MASS AIR FLOW SENSOR
Refer to EM-16, "AIR CLEANER AND AIR DUCT" .
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.800 - 2.200
PBIA9559J
SEF 0 12 P

EC-218Revision: June 2006
DTC P0128 THERMOSTAT FUNCTION
2007 Versa
DTC P0128 THERMOSTAT FUNCTIONPFP:21200
On Board Diagnosis LogicUBS00QEG
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 ProcedureUBS00QEH
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 engine coolant temperature of –10°C (14°F) to 71°C (160°F).
WITH CONSULT-II
1. Replace thermostat with new one. Refer to CO-18, "THERMOSTAT" . Use only a genuine NISSAN ther-
mostat as a replacement. If an incorrect thermostat is used, the MIL may come on.
2. Turn ignition switch ON.
3. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with
CONSULT-II.
4. Check that the “COOLAN TEMP/S” is above 71°C (160°F).
If it is below 71°C (160°F), go to following step.
If it is above 71°C (160°F), cool down the engine to less than
71°C (160°F), then retry from step 1.
5. Drive vehicle for 10 consecutive minutes under the following
conditions.
If 1st trip DTC is detected, go to EC-218, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00QEI
1. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-219, "
Component Inspection" .
OK or NG
OK >>INSPECTION END
NG >> Replace engine coolant temperature sensor.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128Thermostat functionThe engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough.

Thermostat

Leakage from sealing portion of thermo-
stat

Engine coolant temperature sensor
VHCL SPEED SE 80 - 120 km/h (50 - 75 MPH)
SEF 1 76 Y

DTC P0128 THERMOSTAT FUNCTION
EC-219
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Component InspectionUBS00QEJ
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.
<Reference data>
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationUBS00QEK
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-18, "THERMOSTAT" .
PBIB2005E
Engine coolant temperature°C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF 0 12 P

EC-220Revision: June 2006
DTC P0130 A/F SENSOR 1
2007 Versa
DTC P0130 A/F SENSOR 1PFP:22693
Component DescriptionUBS00QEL
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-II Reference Value in Data Monitor ModeUBS00QEM
Specification data are reference values.
On Board Diagnosis LogicUBS00QEN
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the air fuel ratio (A/
F) sensor 1 signal fluctuates according to fuel feedback control.
DTC Confirmation ProcedureUBS00QEO
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 11V at idle.
PROCEDURE FOR MALFUNCTION A
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
PBIB3353E
PBIB3354E
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 2.2V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0130
0130
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuitA)The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly in the range other
than approx. 2.2V.

Harness or connectors
[Air fuel ratio (A/F) sensor 1 cir-
cuit is open or shorted.]

Air fuel ratio (A/F) sensor 1 P0150
0150
(Bank 2)B)The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 2.2V.

DTC P0130 A/F SENSOR 1
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2. Select “DATA MONITOR” mode with CONSULT-II.
3. Let engine idle for 2 minutes.
4. If 1st trip DTC is detected, go to EC-224, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” in “DATA MONITOR” mode with CONSULT-II.
3. Check “A/F SEN1 (B1)” indication.
If the indication is constantly approx. 2.2V and does not fluctuates, go to EC-224, "
Diagnostic Procedure" .
If the indication fluctuates around 2.2V, 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-II.
5. Touch “START”.
6. When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II 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.
SEF 1 74 Y
ENG SPEED 1,600 - 3,200 rpm
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, CVT)
5th position (M/T)
SEF 5 76 Z
SEF 5 77 Z