EC-298
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0172 FUEL INJECTION SYSTEM FUNCTION
P0172 FUEL INJECTIO
N SYSTEM FUNCTION
DTC LogicINFOID:0000000009462236
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 perform the following procedure
before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-1
1. Clear the mixture ratio self-learning value. Refer to EC-181, "Work Procedure"
.
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 >> Proceed to EC-299, "Diagnosis Procedure".
NO >> Check exhaust and intake air leak visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-2
1. Start engine and let it idle for at least 5 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-299, "Diagnosis Procedure".
NO >> GO TO 5.
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No.CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0172 FUEL SYS-RICH-B1
(System too rich bank 1) • 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: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0172 FUEL INJECTION SYSTEM FUNCTIONEC-299
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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5.PERFORM DTC CONFIRMATION PROCEDURE-3
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine.
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 >> Proceed to EC-299, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462237
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
Is exhaust gas leak detected?
YES >> Repair or replace error-detected parts.
NO >> GO TO 2.
2.CHECK FOR INTAKE AIR LEAK
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
Intake air leak detected?
YES >> Repair or replace error-detected parts.
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.
*1: Except for California
*2: For California
5. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector
and ground.
VHCL SPEED SE 50 - 120 km/h (31 - 75 MPH)
PBIB1216E
+ −
Continuity
A/F sensor 1 ECM
Connector Terminal Connector Terminal
F24 1
F14
*1
F91*2
41
Existed
245
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-300
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0172 FUEL INJECTION SYSTEM FUNCTION
*1: Except for California
*2: For California
6. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK FUEL PRESSURE
Check fuel pressure. Refer to EC-182, "Work Procedure"
.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging. Refer to EM-41, "Exploded View"
.
Is the inspection result normal?
YES >> Replace “fuel filter and fuel pump assembly”. Refer to FL-6, "Removal and Installation".
NO >> Repair or replace error-detected parts.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITO R” mode of “ENGINE” using CONSULT.
3. For specification, refer to EC-541, "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-541, "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-228, "DTC Logic"
.
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode of “ENGINE” using CONSULT.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT
1. Let engine idle.
+
−Continuity
A/F sensor 1
Connector Terminal
F24 1
Ground Not existed
2
+ −Continuity
ECM
Connector Terminal
F14
*1
F91*2
41 Ground Not existed
45
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-302
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0181 FTT SENSOR
P0181 FTT SENSOR
DTC LogicINFOID:0000000009462238
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Is it necessary to erase permanent DTC?
YES >> GO TO 7.
NO >> GO TO 2.
2.PRECONDITIONING
If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-
dure before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-1
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-304, "Diagnosis Procedure".
NO >> GO TO 4.
4.CHECK ENGINE COOLANT TEMPERATURE
With CONSULT
1. Select “COOLAN TEMP/S” in “DATA MONITOR” of “ENGINE” using CONSULT.
2. Check “COOLAN TEMP/S” value.
With GST
Follow the procedure “With CONSULT” above.
“
COOLAN TEMP/S” less than 60°C (140°F)?
YES >> INSPECTION END
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-2
With CONSULT
1. Cool engine down until “COOLAN TEMP/S” is less than 60 °C (140 °F).
DTC No. CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0181 FTT SENSOR
(Fuel temperature sensor ″A ″
circuit range/performance) A)
Rationally incorrect voltage from the
sensor is sent to ECM, compared with
the voltage signals from ECT sensor
and intake air temperature sensor. • Harness or connectors
(FTT sensor circuit is open or shorted)
• FTT sensor
• Combination meter
B) The comparison result of signals trans-
mitted to ECM from each temperature
sensor (IAT sensor, ECT sensor, EOT
sensor, and FTT sensor) shows that
the voltage signal of the FTT sensor is
higher/lower than that of other temper-
ature sensors when the engine is start-
ed with its cold state. • Harness or connectors
(High or low resistance in the FTT
sensor circuit)
• FTT sensor
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0181 FTT SENSOREC-303
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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2. Wait at least 10 seconds.
3. Check 1st trip DTC.
With GST
Follow the procedure “With CONSULT” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-304, "Diagnosis Procedure".
NO >> GO TO 6.
6.PERFORM COMPONENT FUNCTION CHECK (FOR MALFUNCTION B)
Perform component function check. Refer to EC-303, "Component Function Check"
.
NOTE:
Use the component function check to check the overall func tion of the FTT sensor circuit. During this check, a
1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-304, "Diagnosis Procedure"
.
7.PRECONDITIONING
If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-
dure before conducti ng the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
• Before performing the following procedure, do not add fuel.
• Before performing the following procedure, check that fuel level is between 1/4 and 4/4.
• Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 8.
8.PERFORM DTC CONFIRMATION PROCEDURE B
1. Move the vehicle to a cool place. NOTE:
Cool the vehicle in an environment of ambient air temperature between −10 °C (14 °F) and 35 °C (95 °F).
2. Turn ignition switch OFF and leave the vehicle for 12 hours. CAUTION:
Never turn ignition switch ON during this procedure.
NOTE:
The vehicle must be cooled with the food open.
3. Start engine and let it idle for 5 minutes or more. CAUTION:
Never turn ignition swit ch OFF during idling.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-304, "Diagnosis Procedure".
NO >> INSPECTION END
Component Function CheckINFOID:0000000009462239
1.CHECK FUEL TANK TEM PERATURE (FTT) SENSOR
1. Turn ignition switch OFF.
2. Disconnect fuel level sensor unit and fuel pump harness connector.
3. Remove fuel level sensor unit. Refer to FL-6, "Removal and Installation"
.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-304
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0181 FTT SENSOR
4. Check resistance between fuel level sensor unit and fuel pump
terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-43, "Intermittent Incident".
NO >> Proceed to EC-304, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000009462240
1.INSPECTION START
Confirm the detected malfunc tion (A or B). Refer to EC-302, "DTC Logic"
.
Which malfunction is detected?
A>>GO TO 2.
B>>GO TO 6.
2.CHECK DTC WITH COMBINATION METER
Check DTC with combination meter. Refer to MWI-18, "CONSULT Function (METER/M&A)"
.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Proceed to MWI-61, "Component Function Check"
.
3.CHECK FUEL TANK TEMPERAT URE (FTT) SENSOR POWER
1. Turn ignition switch OFF.
2. Disconnect fuel level sensor unit and fuel pump harness connector.
3. Turn ignition switch ON.
4. Check the voltage between fuel level sens or unit and fuel pump harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK FUEL TANK TEMPERATURE (F TT) SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between fuel level sens or unit and fuel pump harness connector and ECM harness
connector.
Fuel level sensor unit
and fuel pump Condition Resistance (k Ω)
+ −
Te r m i n a l
3 1 Temperature [
°C
( ° F)] 20 (68) 2.3 – 2.7
50 (122) 0.79 – 0.90
JMBIA0167ZZ
+ −Voltag e
(Approx.)
Fuel level sensor unit and fuel pump
Connector Terminal B42 3 Ground 5 V
+-
Continuity
Fuel level sensor unit and
fuel pump ECM
Connector Terminal Connector Terminal
B42 3 E10
*1
E31*2125 Existed
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0181 FTT SENSOREC-305
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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*1: Except for California
*2: For California
4. Also check harness for short to ground and to power.
Is the inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit.
NO >> Repair or replace error-detected parts.
5.CHECK FTT SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between fuel level sens or unit and fuel pump harness connector and ECM harness
connector.
*1: Except for California
*2: For California
4. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace error-detected parts.
6.CHECK FUEL TANK TEM PERATURE (FTT) SENSOR
Check the FTT sensor. Refer to EC-305, "Component Inspection"
.
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-43, "Intermittent Incident".
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-6, "Removal and Installation"
.
Component InspectionINFOID:0000000009462241
1.CHECK FUEL TANK TEMPERATURE (FTT) SENSOR
1. Turn ignition switch OFF.
2. Disconnect fuel level sensor unit and fuel pump harness connector.
3. Remove fuel level sensor unit. Refer to FL-6, "Removal and Installation"
.
4. Check resistance between fuel level sensor unit and fuel pump terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-6, "Removal and Installation"
.
+-
Continuity
Fuel level sensor unit and
fuel pump ECM
Connector Terminal Connector Terminal
B42 1 E10
*1
E31*2124 Existed
Fuel level sensor unit
and fuel pump Condition Resistance (k Ω)
+ −
Te r m i n a l
31 Temperature
[ ° C ( °F)] 20 (68) 2.3 – 2.7
50 (122) 0.79 – 0.90
JMBIA0167ZZ
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-306
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0182, P0183
FTT SENSOR
P0182, P0183 FTT SENSOR
DTC LogicINFOID:0000000009462242
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-306, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462243
1.CHECK DTC WITH COMBINATION METER
Refer to MWI-18, "CONSULT Function (METER/M&A)"
.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Proceed to MWI-61, "Component Function Check"
.
2.CHECK FUEL TANK TEMPERATURE (FTT) SENSOR POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect fuel level sensor unit and fuel pump harness connector.
3. Turn ignition switch ON.
4. Check the voltage between fuel level sens or unit and fuel pump harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
DTC No. CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0182 FTT SEN/CIRCUIT
(Fuel temperature sensor
″ A ″ circuit low) An excessively low voltage from the sensor is
sent to ECM. • Harness or connectors
(The FTT sensor circuit is open or
shorted.)
• Fuel tank temperature sensor
• Combination meter
P0183 FTT SEN/CIRCUIT
(Fuel temperature sensor
″ A ″ circuit high) An excessively high voltage from the sensor is
sent to ECM.
+
−Vol tag e
(Approx.)
Fuel level sensor unit and fuel
pump
Connector Terminal B42 3 Ground 5 V
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM