NISSAN LATIO 2011 Service Repair Manual

P0171 FUEL INJECTION SYSTEM FUNCTIONEC-237
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7. Crank engine for about 3 seconds.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Replace fuel injectors from which fuel does not spray
out. Always replace O-ring with new ones. Refer to EM-
33, "Exploded View".
9.CHECK INTERMITTENT INCIDENT
Refer to EC-122, "
Diagnosis Procedure".
>> INSPECTION END
Fuel should be sprayed evenly for each fuel injector.
PBIA9666J
Revision: May 2010
2011 Versa

EC-238
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P0172 FUEL INJECTION SYSTEM FUNCTION
P0172 FUEL INJECTIO
N SYSTEM FUNCTION
DTC LogicINFOID:0000000005929913
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio f eedback signal from the A/F sensors 1. The ECM calcu-
lates the necessary compensation to correct the of fset between the actual and the theoretical ratios.
In case the amount of the compensation value is extrem ely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Clear the mixture ratio self-learning value. Refer to EC-27, "
MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the f uel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.
Does engine start?
YES >> Go to EC-240, "Diagnosis Procedure".
NO >> Check exhaust and intake air leak visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Start engine and let it idle for at least 5 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-240, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine.
Sensor Input signal to ECM ECM functionActuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio
feedback signal) Fuel injection control Fuel injector
DTC No. Trouble diagnosis name
DTC detecting condition Possible cause
P0172 Fuel injection system too
rich • Fuel injection system does not operate properly.
• The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.) • A/F sensor 1
• Fuel injector
• Exhaust gas leaks
• Incorrect fuel pressure
• Mass air flow sensor
Revision: May 2010
2011 Versa

P0172 FUEL INJECTION SYSTEM FUNCTIONEC-239
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3. Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.
CAUTION:
Always drive vehicle at a safe speed.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-240, "Diagnosis Procedure".
NO >> INSPECTION END
VHCL SPEED SE 50 - 120 km/h (31 - 75 MPH)
Revision: May 2010 2011 Versa

EC-240
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P0172 FUEL INJECTION SYSTEM FUNCTION
Wiring Diagram
INFOID:0000000006141115
Diagnosis ProcedureINFOID:0000000005929915
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
AABWA0309GB
Revision: May 2010 2011 Versa

P0172 FUEL INJECTION SYSTEM FUNCTIONEC-241
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2. Listen for an exhaust gas leak before three way catalyst (manifold).
Is exhaust gas leak detected?
YES >> Repair or replace. Refer to
EM-30, "Exploded View".
NO >> GO TO 2.
2.CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor. Refer to EM-25, "
Exploded View".
Is intake air leak detected?
YES >> Repair or replace.
NO >> GO TO 3.
3.CHECK A/F SENSOR 1 IN PUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
5. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector
and ground.
6. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Check fuel pressure. Refer to EC-499, "
Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
PBIB1216E
A/F sensor 1 ECM
Continuity
Connector Terminal Connector Terminal
F12 1
F11 49
Existed
25 3
A/F sensor 1 Ground Continuity
Connector Terminal
F12 1
Ground Not existed
2
ECM Ground Continuity
Connector Terminal
F11 49
Ground Not existed
53
Revision: May 2010 2011 Versa

EC-242
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P0172 FUEL INJECTION SYSTEM FUNCTION
5. DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
YES >> Replace “fuel level sensor unit, fuel filter and fuel pump assembly”. Refer to FL-6, "Component".
NO >> Repair or replace
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
3. For specification, refer to EC-503, "
Mass Air Flow Sensor".
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in “Service $01” with GST.
3. For specification, refer to EC-503, "
Mass Air Flow Sensor".
Is the measurement value within the specification?
YES >> GO TO 7.
NO >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to EC-150, "
DTC Logic".
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-III
1. Let engine idle.
2. Listen to each fuel injector operating sound.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Perform trouble diagnosis for FUEL INJECTOR, refer to EC-433, "
Component Function Check".
8.CHECK FUEL INJECTOR
1. Remove fuel injector assembly. Refer to EM-33, "
Removal and Installation".
Keep fuel hose and all fuel injectors connected to fuel tube.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all fuel injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each fuel injectors.
6. Crank engine for about 3 seconds.
Make sure fuel does not drip from fuel injector.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Replace the fuel injectors from which fuel is dripping. Always replace O-ring with new one. Refer
to EM-33, "
Exploded View".
9.CHECK INTERMITTENT INCIDENT
Refer to EC-122, "
Diagnosis Procedure".
Clicking noise should be heard.
PBIB3332E
Revision: May 2010 2011 Versa

P0172 FUEL INJECTION SYSTEM FUNCTIONEC-243
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>> INSPECTION END
Revision: May 2010
2011 Versa

EC-244
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P0181 FTT SENSOR
P0181 FTT SENSOR
DescriptionINFOID:0000000005929916
The fuel tank temperature sensor
is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a the rmistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: These data are reference values and are measured between ECM terminal 43 (Fuel tank temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output volt age. Doing so may result in damage to the ECM's transis-
tor. Use a ground other than ECM terminals, such as the ground.
DTC LogicINFOID:0000000005929917
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Turn ignition switch and wait at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-246, "Diagnosis Procedure".
NO >> GO TO 3.
3.CHECK ENGINE COOLANT TEMPERATURE
With CONSULT-III
1. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.
2. Check “COOLAN TEMP/S” indication.
With GST
Follow the procedure “With CONSULT-III” above.
Is
“COOLAN TEMP/S” indication less than 60°C (140°F)?
YES >> INSPECTION END
NO >> GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
Fluid temperature
[° C ( °F)] Voltage*
[V] Resistance
[kΩ]
20 (68) 3.52.3 - 2.7
50 (122) 2.20.79 - 0.90
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0181 Fuel tank temperature
sensor circuit range/per-
formance Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signals
from engine coolant temperature sensor and in-
take air temperature sensor. • Harness or connectors
(The sensor circuit is open or shorted)
• Fuel tank temperature sensor
Revision: May 2010 2011 Versa

P0181 FTT SENSOREC-245
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With CONSULT-III
1. Cool engine down until “COOLAN TE MP/S” indication is less than 60°C (140° F).
2. Wait at least 10 seconds.
3. Check 1st trip DTC.
With GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-246, "Diagnosis Procedure".
NO >> INSPECTION END
Revision: May 2010 2011 Versa

EC-246
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P0181 FTT SENSOR
Wiring Diagram
INFOID:0000000005929918
Diagnosis ProcedureINFOID:0000000005929919
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connections E15, E24. Refer to EC-127, "
Ground Inspection".
Is the inspection result normal?
BBWA2636E
Revision: May 2010 2011 Versa