2009 NISSAN LATIO service

DTC P0122, P
0123 TP SENSOR
EC-683
< SERVICE INFOMATION >
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>>
INSPECTION END 7.
CHECK INTERMITTENT INCIDENT
Refer to EC-626 .
>> INSPECTION END
Component Inspection INFOID:0000000004537149
THROTTLE POSITION SENSOR 1. Reconnect all harness connectors disconnected.
2. Perform EC-572, " Throttle Valve Closed Position Learning " .
3. Turn ignition switch ON.
4. Set shift lever to D position (A/T, CVT) or 1st position (M/T).
5. Check voltage between ECM terminals 33 (TP sensor 1 signal), 34 (TP sensor 2 signal) and ground under the following condi-
tions.
6. If NG, replace electric throttle control actuator and go to the next
step.
7. Perform EC-572, " Throttle Valve Closed Position Learning " .
8. Perform EC-572, " Idle Air Volume Learning " .
Removal and Installation INFOID:0000000004537150
ELECTRIC THROTTLE CONTROL ACTUATOR Refer to EM-141 .
Terminal Accelerator pedal Voltage
33
(Throttle position sensor 1) Fully released More than 0.36V
Fully depressed Less than 4.75V
34
(Throttle position sensor 2) Fully released Less than 4.75V
Fully depressed More than 0.36V PBIB3038E

EC-684< SERVICE INFOMATION >
[MR TYPE 1]
DTC P0125 ECT SENSOR
DTC P0125 ECT SENSOR
Description INFOID:0000000004537151
NOTE:
If DTC P0125 is displayed with P0117 or P0118, fi rst perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-674 .
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 elec trical resistance of the ther-
mistor decreases as temperature increases.

*: 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 in put/output voltage. Doing 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 Diagn osis Logic INFOID:0000000004537152
This self-diagnosis ha one trip detection logic.
DTC Confirmation Procedure INFOID:0000000004537153
CAUTION:
Be careful not to overheat engine.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, 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 k
Ω
− 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 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

DTC P0125 ECT SENSOR
EC-685
< SERVICE INFOMATION >
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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-685, " Diagnosis Procedure " .
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis Procedure INFOID:00000000045371541.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-632, " Ground Inspection " .
OK or NG OK >> GO TO 2.
NG >> Repair or replace ground connections. 2.
CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-686, " 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-45 .
4.
CHECK INTERMITTENT INCIDENT
Refer to EC-626 .
Refer to EC-676, " Wiring Diagram " .
>> INSPECTION END :
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15 BBIA0698E

EC-686< SERVICE INFOMATION >
[MR TYPE 1]
DTC P0125 ECT SENSOR
Component Inspection INFOID:0000000004537155
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 Installation INFOID:0000000004537156
ENGINE COOLANT TEMPERATURE SENSOR
Refer to EM-186 . 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

DTC P0127 IAT SENSOR
EC-687
< SERVICE INFOMATION >
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DTC P0127 IAT SENSOR
Component Description INFOID:0000000004537157
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. Electric al 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 Logic INFOID:0000000004537158
DTC Confirmation Procedure INFOID:0000000004537159
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, 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 90 °C (194 °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 90 °C (194 °F), turn ignition switch OFF and cool down
engine.
• Perform the following steps before engine coolant temperature is above 90 °C (194 °F). 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 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

EC-688< SERVICE INFOMATION >
[MR TYPE 1]
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-688, " Diagnosis Procedure " .
WITH GST
Follow the procedure “With CONSULT-III” above.
Diagnosis Procedure INFOID:00000000045371601.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-632, " Ground Inspection " .
OK or NG OK >> GO TO 2.
NG >> Repair or replace ground connections. 2.
CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-688, " 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-626 .
Refer to EC-671, " Wiring Diagram " .
>> INSPECTION END
Component Inspection INFOID:0000000004537161
INTAKE AIR TEMPERATURE SENSOR :
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15 BBIA0698E

DTC P0127 IAT SENSOR
EC-689
< SERVICE INFOMATION >
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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 Installation INFOID:0000000004537162
MASS AIR FLOW SENSOR Refer to EM-139 .
Intake air temperature
°C ( °F) Resistance k Ω
25 (77) 1.800 - 2.200 PBIA9559J
SEF012P

DTC P0128 THERMOSTAT FUNCTION
EC-691
< SERVICE INFOMATION >
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Component Inspection
INFOID:0000000004537166
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 Installation INFOID:0000000004537167
ENGINE COOLANT TEMPERATURE SENSOR Refer to EM-186 . 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