EC-296
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0171 FUEL INJECTION SYSTEM FUNCTION
5. Check the continuity between A/F sensor 1
harness connector and ground, or ECM harness connector
and ground.
*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-232, "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
+ −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-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
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-318
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0300, P0301,
P0302, P0303, P0304 MISFIRE
P0300, P0301, P0302, P0303, P0304 MISFIRE
DTC LogicINFOID:0000000009462255
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 that will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can dam age the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level that 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
light when the misfire is detected on a second trip. Du ring this condition, the ECM monitors the CKP sen-
sor signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on 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-1
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Restart engine and let it idle for about 15 minutes.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-319, "Diagnosis Procedure".
Sensor Input signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0300 MULTI CYL MISFIRE
(Random/multiple cylinder misfire detected) Multiple cylinder misfire.
• Improper spark plug
• Insufficient compression
• Incorrect fuel pressure
• Fuel Injector circuit is open or shorted
• Fuel injector
• Intake air leak
• Ignition signal circuit is open or shorted
• Lack of fuel
• Signal plate
• A/F sensor 1
• Incorrect PCV hose connection
P0301
CYL 1 MISFIRE
(Cylinder 1 Misfire Detected) No. 1 cylinder misfires.
P0302 CYL 2 MISFIRE
(Cylinder 2 Misfire Detected) No. 2 cylinder misfires.
P0303 CYL 3 MISFIRE
(Cylinder 3 Misfire Detected) No. 3 cylinder misfires.
P0304 CYL 4 MISFIRE
(Cylinder 4 Misfire Detected) No. 4 cylinder misfires.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-320
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0300, P0301,
P0302, P0303, P0304 MISFIRE
4.CHECK FUNCTION OF FUEL INJECTOR
1. Start engine and let engine idle.
2. Listen to each fuel injector operating sound.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Perform trouble diagnosis for FUEL INJECTOR. Refer
to EC-505, "Diagnosis Procedure"
.
5.CHECK FUNCTION OF IGNITION COIL-1
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
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 two or three 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 about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spar k plug and the ignition coil
within 50 cm (19.7 in). Be car eful not to get an electrical
shock while checking, becau se 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 9.
NO >> GO TO 6.
6.CHECK FUNCTION OF IGNITION COIL-2
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.
Is the inspection result normal?
Clicking noise should be heard.
PBIB3332E
Spark should be generated.
JMBIA0066GB
Spark should be generated.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0300, P0301, P0302, P0303, P0304 MISFIRE
EC-321
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
C
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EC
NP
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YES >> GO TO 7.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-511, "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-111, "Standard and Limit"
.
NO >> Repair or clean spark plug. Then GO TO 8.
8.CHECK FUNCTION OF IGNITION COIL-3
1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck 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-111, "Standard
and Limit".
9.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-26, "Compression pressure"
.
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.
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-182, "Work Procedure"
.
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.
12.CHECK IGNITION TIMING
Check the following items.
For procedure, refer to EC-170, "Work Procedure"
.
For specification, refer to EC-541, "Ignition Timing"
.
Is the inspection result normal?
YES >> GO TO 13.
NO >> Follow the EC-170, "Work Procedure"
.
SEF156I
Spark should be generated.
At idling: Approximately 350 kPa (3.57 kg/cm
2, 51 psi)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
EC-334
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0420 THREE WAY CATALYST FUNCTION
Diagnosis Procedure
INFOID:0000000009462268
1.CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst (manifold).
Is exhaust gas leak detected?
YES >> Repair or replace error-detected parts.
NO >> GO TO 3.
3.CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
Is intake air leak detected?
YES >> Repair or replace error-detected parts.
NO >> GO TO 4.
4.CHECK IGNITION TIMING AND IDLE SPEED
Check the following items. Refer to EC-170, "Work Procedure"
.
For specification, refer to EC-541, "Ignition Timing"
For specification, refer to EC-541, "Idle Speed".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Follow the EC-170, "Work Procedure"
.
5.CHECK FUEL INJECTOR
Check the fuel injector. Refer to EC-505, "Component Function Check"
.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Perform EC-505, "Diagnosis Procedure"
.
6.CHECK FUNCTION OF IGNITION COIL-1
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
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 two or three 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.
PBIB1216E
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
P0441 EVAP CONTROL SYSTEMEC-337
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
C
D E
F
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EC
NP
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P0441 EVAP CONTROL SYSTEM
DTC LogicINFOID:0000000009462269
DTC DETECTION LOGIC
NOTE:
If DTC P0441 is displayed with other DTC such as P2122, P2123, P2127, P2128 or P2138, first perform
trouble diagnosis for other DTC.
In this evaporative emission (EVAP) control system, pur ge flow occurs during non-closed throttle conditions.
Purge volume is related to air intake volume. Under normal purge conditions (non-closed throttle), the EVAP
canister purge volume control solenoid valve is open to admit purge flow. Purge flow exposes the EVAP con-
trol system pressure sensor to intake manifold vacuum.
Under normal conditions (non-closed throttle), sensor output voltage indicates if pressure drop and purge flow
are adequate. If not, a malfunction is determined.
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.
Will CONSULT be used?
YES >> GO TO 2.
NO >> GO TO 5.
JSBIA0416GB
DTC No. CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0441 EVAP PURG FLOW/MON
(Evaporative emission sys-
tem incorrect purge flow) EVAP control system does not operate
properly, EVAP control system has a leak
between intake manifold and EVAP control
system pressure sensor. • EVAP canister purge volume control sole-
noid valve stuck closed
• EVAP control system pressure sensor and the circuit
• Loose, disconnected or improper connection of rubber tube
• Blocked rubber tube
• Cracked EVAP canister
• EVAP canister purge volume control sole- noid valve circuit
• Accelerator pedal position sensor
• Blocked purge port
• EVAP canister vent control valve
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM