2009 NISSAN LATIO check engine

EC-160< COMPONENT DIAGNOSIS >
[HR16DE]
P0102, P0103 MAF SENSOR
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 2. 2.
CHECK FOR THE CAUSE OF UNEVEN AIR FL OW THROUGH MASS AIR FLOW SENSOR
1. Turn ignition switch OFF.
2. Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
- Crushed air ducts
- Malfunctioning seal of air cleaner element
- Uneven dirt of air cleaner element
- Improper specification of intake air system parts
Is the inspection result normal? YES >> GO TO 4.
NO >> GO TO 3. 3.
CHECK MASS AIR FLOW SENSOR-II
With CONSULT-III
1. Repair or replace malfunctioning part.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Without CONSULT-III
1. Repair or replace malfunctioning part.
2. Start engine and warm it up to normal operating temperature.
3. Check the voltage between ECM harness connector and
ground.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 4. 4.
CHECK MASS AIR FLOW SENSOR-III
With CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor harness connector and reconnect it again.
3. Start engine and warm it up to normal operating temperature. Monitor item Condition MAS A/F SE-B1
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4 V
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.3 V
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9 V
Idle to about 4,000 rpm 0.9 - 1.3 V to Approx. 2.4 V*
ECM Ground Condition Voltage
Con-
nector Termi-
nal
F11 45
(MAF
sensor
signal) Ground Ignition switch ON (Engine stopped.) Approx. 0.4 V
Idle (Engine is wa rmed-up to normal
operating temperature.) 0.9 - 1.3 V
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.4 - 1.9 V
Idle to about 4,000 rpm 0.9 - 1.3 V to
Approx. 2.4 V* PBIA9564J

P0102, P0103 MAF SENSOR
EC-161
< COMPONENT DIAGNOSIS >
[HR16DE] C
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4. Connect CONSULT-III and select “DATA MONITOR” mode.
5. Select “MAS A/F SE-B1” and check indication.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Without CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor har ness connector and reconnect it again.
3. Start engine and warm it up to normal operating temperature.
4. Check the voltage between ECM harness connector and ground.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal? YES >> INSPECTION END
NO >> Clean or replace mass air flow sensor. Monitor item Condition MAS A/F SE-B1
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4 V
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.3 V
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9 V
Idle to about 4,000 rpm 0.9 - 1.3 V to Approx. 2.4 V*
ECM Ground Condition Voltage
Con-
nector Termi-
nal
F11 45
(MAF
sensor signal) Ground Ignition switch ON (Engine stopped.) Approx. 0.4 V
Idle (Engine is wa rmed-up to normal
operating temperature.) 0.9 - 1.3 V
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.4 - 1.9 V
Idle to about 4,000 rpm 0.9 - 1.3 V to
Approx. 2.4 V* PBIA9564J

P0116 ECT SENSOR
EC-165
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[HR16DE] C
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P0116 ECT SENSOR
Description INFOID:0000000004780447
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.

*: These data are reference values and are measured between ECM terminal 38
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output vo ltage. Doing so may result in damage to the ECM's transis-
tor. Use a ground other than ECM terminals, such as the ground.
DTC Logic INFOID:0000000004780084
DTC DETECTION LOGIC NOTE:
If DTC P0116 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-167, " DTC Logic " .
DTC CONFIRMATION PROCEDURE 1.
PRECONDITIONING
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.
>> GO TO 2. 2.
PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and warm it up to normal operating temperature.
2. Rev engine up to 2,000 rpm for more than 10 minutes.
3. Move the vehicle to a cool place, then stop engine and turn ignition switch OFF.
4. Check resistance between “fuel level s ensor unit and fuel pump” terminals 4 and 5. SEF594K
Engine coolant temperature
[° C ( °F)] Voltage* (V) Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.37 - 2.63
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
P0116 Engine coolant temperature
sensor circuit range/perfor-
mance Engine coolant temperature signal from engine
coolant temperature sensor does not fluctuate,
even when some time has passed after starting
the engine with pre-warming up condition. • Harness or connectors
(High or low resistance in the circuit)
• Engine coolant temperature sensor

P0117, P0118 ECT SENSOR
EC-167
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[HR16DE] C
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P0117, P0118 ECT SENSOR
Description INFOID:0000000004780087
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.

*: These data are reference values and are measured between ECM terminal 38
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output vo ltage. Doing so may result in damage to the ECM's transis-
tor. Use a ground other than ECM terminals, such as the ground.
DTC Logic INFOID:0000000004780088
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE 1.
PRECONDITIONING
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.
>> GO TO 2. 2.
PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check DTC.
Is DTC detected? YES >> Go to
EC-168, " Diagnosis Procedure " .
NO >> INSPECTION END SEF594K
Engine coolant temperature
[° C ( °F)] Voltage* (V) Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.37 - 2.63
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
P0117 Engine coolant temperature
sensor circuit low input An excessively low voltage from the sensor
is sent to ECM. • Harness or connectors
(The sensor circuit is open or shorted.)
• Engine coolant temperature sensor
P0118 Engine coolant temperature
sensor circuit high input An excessively high voltage from the sensor
is sent to ECM.

EC-170< COMPONENT DIAGNOSIS >
[HR16DE]
P0117, P0118 ECT 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. Terminals Condition Resistance
1 and 2 Temperature [ °C ( °F)] 20 (68) 2.37 - 2.63 k
Ω
50 (122) 0.68 - 1.00 k Ω
90 (194) 0.236 - 0.260 k Ω PBIB2005E

P0125 ECT SENSOR
EC-175
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[HR16DE] C
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P0125 ECT SENSOR
Description INFOID:0000000004780096
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.

*: These data are reference values and are measured between ECM terminal 38
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output vo ltage. Doing so may result in damage to the ECM's transis-
tor. Use a ground other than ECM terminals, such as the ground.
DTC Logic INFOID:0000000004780097
DTC DETECTION LOGIC NOTE:
• If DTC P0125 is displayed with P0 116, first perform the trouble diagnosis for DTC P0116. Refer to EC-165, " 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-167, " DTC Logic " .
DTC CONFIRMATION PROCEDURE 1.
PRECONDITIONING
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.
>> GO TO 2. 2.
CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
With CONSULT-III
1. Turn ignition switch ON. SEF594K
Engine coolant temperature
[° C ( °F)] Voltage* (V) Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.37 - 2.63
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 Insufficient engine coolant
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

P0125 ECT SENSOR
EC-177
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[HR16DE] C
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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. Terminals Condition Resistance
1 and 2 Temperature [ °C ( °F)] 20 (68) 2.37 - 2.63 k
Ω
50 (122) 0.68 - 1.00 k Ω
90 (194) 0.236 - 0.260 k Ω PBIB2005E

EC-178< COMPONENT DIAGNOSIS >
[HR16DE]
P0127 IAT SENSOR
P0127 IAT SENSOR
Description INFOID:0000000004780100
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.

*: These data are reference values and are 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.
DTC Logic INFOID:0000000004780101
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE 1.
PRECONDITIONING
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.
>> GO TO 2. 2.
PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Wait until engine coolant temperature is less than 96 °C (205 °F)
- Turn ignition switch ON.
- Select “DATA MONITOR” mode with CONSULT-III.
- 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. 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 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
(The sensor circuit is open or shorted)
• Intake air temperature sensor