P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-789
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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, short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-687, "Work Procedure"
.
2. Install fuel pressure gauge kit [SST: — (J-44321)] and check fuel pressure. Refer to EC-687, "Work Proce-
dure".
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.
Is the inspection result normal?
YES >> Replace “fuel filter and fuel pump assembly”. Refer to FL-6, "Removal and Installation".
NO >> Repair or replace malfunctioning part.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT. For specification, refer to EC-998, "Mass Air Flow Sensor"
.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST. For specification, refer to EC-998, "Mass Air Flow Sensor"
.
Is the measurement value within the specification?
YES >> GO TO 7.
NO >> Check connectors for rusted terminals or loose c onnections in the mass air flow sensor circuit or
ground. Refer to EC-732, "Diagnosis Procedure"
.
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT
DTC A/F sensor 1
Ground Continuity
Bank Connector Terminal
P0171 1 F12 1
Ground Not existed
2
P0174 2 F61 1
2
DTC ECM
Ground Continuity
Connector Terminal
P0171 F79 69
Ground Not existed
73
P0174 77
81
At idling: Approximately 350 kPa (3.57 kg/cm2, 51 psi)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-791
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P0172, P0175 FUEL INJE
CTION SYSTEM FUNCTION
DTC LogicINFOID:0000000009462647
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 A/F sensor 1. The ECM calculates
the necessary compensation to co rrect the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too rich), the ECM
judges the condition as the fuel injection system malfunc tion and illuminates the MIL (2 trip detection logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing 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-I
1. Clear the mixture ratio self-learning value. Refer to EC-685, "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-792, "Diagnosis Procedure".
NO >> Check exhaust and intake air leakage visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Keep engine idle for at least 5 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-792, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
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. Trouble diagnosis name DTC detecting condition Possible cause
P0172 Fuel injection 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 leakage
• Incorrect fuel pressure
• Mass air flow sensor
P0175
Fuel injection system too
rich (bank 2)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-793
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6. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-687, "Work Procedure"
.
2. Install fuel pressure gauge kit [SST: — (J-44321)] and check fuel pressure. Refer to EC-687, "Work Proce-
dure".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace “fuel filter and fuel pump assembly”. Refer to FL-6, "Removal and Installation"
.
5.CHECK MASS AIR FLOW SENSOR
With CONSULT
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT. For specification, refer to EC-998, "Mass Air Flow Sensor"
.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in “Service $01” with GST. For specification, refer to EC-998, "Mass Air Flow Sensor"
.
Is the measurement value within the specification?
YES >> GO TO 6.
NO >> Check connectors for rusted terminals or loose c onnections in the mass air flow sensor circuit or
ground. Refer to EC-732, "Diagnosis Procedure"
.
6.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT.
3. Check that each circuit produces a momentary engine speed drop.
With GST
1. Let engine idle.
DTC A/F sensor 1
Ground Continuity
Bank Connector Terminal
P0172 1 F12 1
Ground Not existed
2
P0175 2 F61 1
2
DTC ECM
Ground Continuity
Connector Terminal
P0172 F79 69
Ground Not existed
73
P0175 77
81
At idling: Approximately 350 kPa (3.57 kg/cm2, 51 psi)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0300, P0301, P0302, P0303, P0304, P0305, P0306 MISFIRE
EC-809
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P0300, P0301, P0302, P0303,
P0304, P0305, P0306 MISFIRE
DTC LogicINFOID:0000000009462666
DTC DETECTION LOGIC
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary , ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage) On the 1st trip, when a misfire condition occurs that can damage the three way catalyst (TWC) due to
overheating, the MIL will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level t hat will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level t hat will not damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration) For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only
illuminate when the misfire is detected on a second tr ip. During this condition, the ECM monitors the CKP
sensor signal every 1,000 engine revolutions.
A misfire malfunction can be detected in any one cylinder or in multiple cylinders.
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-I
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Restart engine and let it idle for approximately 15 minutes.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
Sensor Input signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300 Multiple cylinder misfires detected Multiple cylinders misfire. • Improper spark plug • Insufficient compression
• Incorrect fuel pressure
• The fuel injector circuit is open or shorted
• Fuel injector
• Intake air leakage
• The ignition signal circuit is open or shorted
• Lack of fuel
• Signal plate
• A/F sensor 1
• Incorrect PCV hose connection
P0301 No. 1 cylinder misfire detected No. 1 cylinder misfires.
P0302 No. 2 cylinder misfire detected No. 2 cylinder misfires.
P0303 No. 3 cylinder misfire detected No. 3 cylinder misfires.
P0304 No. 4 cylinder misfire detected No. 4 cylinder misfires.
P0305 No. 5 cylinder misfire detected No. 5 cylinder misfires.
P0306 No. 6 cylinder misfire detected No. 6 cylinder misfires.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0300, P0301, P0302, P0303, P0304, P0305, P0306 MISFIRE
EC-811
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3. Check that each circuit produces a momentary engine speed drop.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 4.
4.CHECK FUNCTION OF FUEL INJECTOR
1. Start engine and let it idle.
2. Listen to each fuel injector make operation sound.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Perform trouble diagnosis for FUEL INJECTOR, refer to
EC-962, "Diagnosis Procedure"
.
5.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Perform the following procedure in a place with no combustible objects and good ventilation.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure. NOTE:
Do not use CONSULT to release fuel pressure, or fuel pressure applies again during the following proce-
dure.
3. Start engine.
4. After engine stalls, crank it 2 or 3 times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 -
0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
11. Crank engine for approximately 3 seconds, and check whether
spark is generated between the spark plug and the grounded
metal portion.
CAUTION:
• During the operation, always stay 0.5 m (19.7 in) or more away from the spark plug and the ignition coil. Be careful
not to get an electrical sh ock while checking, because the
electrical discharge voltage becomes 20 kV or more.
• It might damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.
NOTE:
When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-
tioning.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 6.
6.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a non-malfunctioning spark plug. Clicking sound should be heard.
PBIB3332E
Spark should be generated.
JMBIA0066GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-812
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P0300, P0301, P030
2, P0303, P0304, P03 05, P0306 MISFIRE
3. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded metal portion.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-967, "Diagnosis Procedure"
.
7.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
Is the inspection result normal?
YES >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-247, "Spark Plug"
.
NO >> Repair or clean spark plug. Then GO TO 8.
8.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded portion.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-247, "Spark
Plug".
9.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-142, "On-Vehicle Service"
.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
10.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-687, "Work Procedure"
.
3. Install fuel pressure gauge kit [SST: — (J-44321)] and check fuel pressure. Refer to EC-687, "Work Proce-
dure".
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
YES >> Replace “fuel filter and fuel pump assembly”. Refer to FL-6, "Removal and Installation".
NO >> Repair or replace malfunctioning part.
12.CHECK IGNITION TIMING
Check idle speed and ignition timing. Spark should be generated.
SEF156I
Spark should be generated.
At idle: Approximately 350 kPa (3.57 kg/cm
2, 51 psi)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0335 CKP SENSOR (POS)EC-817
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P0335 CKP SENSOR (POS)
DTC LogicINFOID:0000000009462671
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing 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 follo wing procedure, confirm that battery vo ltage is more than 10.5 V with igni-
tion switch ON.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 5 seconds. If engine does not start, crank engine for at least 2 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-817, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462672
1.CHECK CRANKSHAFT POSITION (C KP) SENSOR (POS) POWER SUPPLY
1. Disconnect crankshaft position (CKP) sensor (POS) harness connector.
2. Turn ignition switch ON.
3. Check the voltage between CKP sensor (POS) harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0335 Crankshaft position sen-
sor (POS) circuit • The crankshaft position sensor (POS) signal
is not detected by the ECM during the first
few seconds of engine cranking.
• The proper pulse signal from the crankshaft position sensor (POS) is not sent to ECM
while the engine is running.
• The crankshaft position sensor (POS) signal is not in the normal pattern during engine run-
ning. • Harness or connectors
[CKP sensor (POS) circuit is open or
shorted.]
(APP sensor 2 circuit is shorted.)
(EVAP control system pressure sensor
circuit is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
• Crankshaft position sensor (POS)
• Accelerator pedal position sensor
• EVAP control system pressure sensor
• Refrigerant pressure sensor
• Signal plate
• Sensor power supply 2 circuit
CKP sensor (POS) Ground Voltage (V)
Connector Terminal
F30 1 Ground Approx. 5
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-826
< DTC/CIRCUIT DIAGNOSIS >[VQ35DE]
P0420, P0430 THREE WAY CATALYST FUNCTION
Is the inspection result normal?
YES >> GO TO 6.
NO >> Perform EC-962, "Diagnosis Procedure"
.
6.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Perform the following procedure in a place with no combustible objects and good ventilation.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure. NOTE:
Do not use CONSULT to release fuel pressure, or fuel pressure applies again during the following proce-
dure.
3. Start engine.
4. After engine stalls, crank it 2 or 3 times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoi d the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 -
0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
11. Crank engine for approximately 3 seconds, and check whether
spark is generated between the spark plug and the grounded
metal portion.
CAUTION:
• During the operation, always stay 0.5 m (19.7 in) or more away from the spark plug and the ignition coil. Be careful
not to get an electrical s hock while checking, because the
electrical discharge voltage becomes 20 kV or more.
• It might cause to damage the igni tion coil if the gap of more than 17 mm (0.66 in) is taken.
NOTE:
When the gap is less than 13 mm (0.52 in), the sp ark might be generated even if the coil is mal-
functioning.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 7.
7.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded metal portion.
ECM
Voltag e
+–
Connector Terminal Connector Terminal
F78 33
E32 128 Battery voltage
44
45
46
47
48
Spark should be generated.
JMBIA0066GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM