2009 NISSAN LATIO check engine

DTC P0117, P0118 ECT SENSOR
EC-1195
< SERVICE INFOMATION >
[MR TYPE 2] C
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OK or NG OK >> GO TO 2.
NG >> Repair or replace ground connections. 2.
CHECK ECT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature (ECT) sensor (1) har- ness connector.
- : Vehicle front
2. Turn ignition switch ON.
3. Check voltage between ECT sensor terminal 1 and ground with CONSULT-III or tester.
OK or NG OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors. 3.
CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 44 and ECT sensor terminal 2. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. 4.
CHECK ENGINE COOLANT TEMPERATURE SENSOR:
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15 BBIA0698E
PBIB3324E
Voltage: Approximately 5V
PBIB0080E
Continuity should exist.

EC-1196< SERVICE INFOMATION >
[MR TYPE 2]
DTC P0117, P0118 ECT SENSOR
Refer to EC-1190, " Component Inspection " .
OK or NG OK >> GO TO 5.
NG >> Replace engine coolant temperature sensor. 5.
CHECK INTERMITTENT INCIDENT
Refer to EC-1138 .
>> INSPECTION END
Component Inspection INFOID:0000000004501094
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:0000000004501095
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-47, " 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

DTC P0122, P
0123 TP SENSOR
EC-1197
< SERVICE INFOMATION >
[MR TYPE 2] C
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DTC P0122, P0123 TP SENSOR
Component Description INFOID:0000000004500029
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has two sensors. These sensors are a
kind of potentiometers which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. In addition,
these sensors detect the opening and closing speed of the throttle
valve and feed the voltage signals to the ECM. The ECM judges the
current opening angle of the throttle valve from these signals and the
ECM controls the throttle control motor to make the throttle valve
opening angle properly in response to driving condition.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004500030
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagnosis Logic INFOID:0000000004500031
These self-diagnoses have the on e trip detection logic.
NOTE:
If DTC P0122 or P0123 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to EC-1396 .
FAIL-SAFE MODE When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation Procedure INFOID:0000000004500032
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:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-1199, " Diagnosis Procedure " . PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
TP SEN 1-B1
TP SEN 2-B1* • Ignition switch: ON
(Engine stopped)
• Shift lever: D (A/T, CVT),
1st (M/T) Accelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0122
0122 Throttle position sensor
2 circuit low input An excessively low voltage from the TP sensor
2 is sent to ECM. • Harness or connectors
(TP sensor 2 circuit is open or shorted.)
• Electric throttle control actuator (TP sensor 2)
P0123
0123 Throttle position sensor
2 circuit high input An excessively high voltage from the TP sensor
2 is sent to ECM. Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

DTC P0122, P
0123 TP SENSOR
EC-1199
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[MR TYPE 2] C
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Diagnosis Procedure
INFOID:00000000045000341.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-1144, " Ground Inspection " .
OK or NG OK >> GO TO 2.
NG >> Repair or replace ground connections. 2.
CHECK THROTTLE POSITION SEN SOR 2 POWER SUPPLY CIRCUIT
TER-
MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
33 LG Throttle position sensor 1 [Ignition switch: ON]
• Engine stopped
• Shift lever: D (A/T, CVT), 1st (M/T)
• Accelerator pedal: Fully released More than 0.36V
[Ignition switch: ON]
• Engine stopped
• Shift lever: D (A/T, CVT), 1st (M/T)
• Accelerator pedal: Fully depressed Less than 4.75V
34 O Throttle position sensor 2 [Ignition switch: ON]
• Engine stopped
• Shift lever: D (A/T, CVT), 1st (M/T)
• Accelerator pedal: Fully released Less than 4.75V
[Ignition switch: ON]
• Engine stopped
• Shift lever: D (A/T, CVT), 1st (M/T)
• Accelerator pedal: Fully depressed More than 0.36V
36 Y Sensor ground
(Throttle position sensor) [Engine is running]
• Warm-up condition
• Idle speed Approximately 0V
72 V Sensor power supply
(Throttle position sensor) [Ignition switch: ON]
Approximately 5V:
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground E16
4. Body ground E15 BBIA0698E

EC-1202< SERVICE INFOMATION >
[MR TYPE 2]
DTC P0125 ECT SENSOR
DTC P0125 ECT SENSOR
Component Description INFOID:0000000004501093
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 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:0000000004500038
NOTE:
• If DTC P0125 is displayed with P0117 or P0118, firs t perform the trouble diagnosis for DTC P0117 or P0118.
Refer to EC-1193, " DTC Confirmation Procedure " .
• If DTC P0125 is displayed with P0116, first perform the trouble diagnosis for DTC P0116. Refer to EC-1202," DTC Confirmation Procedure " .
DTC Confirmation Procedure INFOID:0000000004500039
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-1203
< SERVICE INFOMATION >
[MR TYPE 2] C
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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-1203, " Diagnosis Procedure " .
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis Procedure INFOID:00000000045000401.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-1144, " Ground Inspection " .
OK or NG OK >> GO TO 2.
NG >> Repair or replace ground connections. 2.
CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-1204, " 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, " Removal and Installation " .
4.
CHECK INTERMITTENT INCIDENT
Refer to EC-1138 .
Refer to EC-1194, " Wiring Diagram " .
>> INSPECTION END :
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15 BBIA0698E

EC-1204< SERVICE INFOMATION >
[MR TYPE 2]
DTC P0125 ECT SENSOR
Component Inspection INFOID:0000000004501098
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:0000000004501099
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-47, " 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

DTC P0127 IAT SENSOR
EC-1205
< SERVICE INFOMATION >
[MR TYPE 2] C
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DTC P0127 IAT SENSOR
Component Description INFOID:0000000004501162
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:0000000004500044
DTC Confirmation Procedure INFOID:0000000004500045
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 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 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