Nissan Altima L32. Manual - part 414

P0300, P0301, P0302, P0303, P0304 MISFIRE

EC-777

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

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2. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain

time. Refer to the table below.

Hold the accelerator pedal as steady as possible.

The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-

ditions should be satisfied at the same time.

CAUTION:

Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws when

driving.

The time to driving varies according to the engine speed in the freeze frame data.

3. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Go to 

EC-777, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000004349744

1.

CHECK FOR INTAKE AIR LEAK AND PCV HOSE

1. Start engine and run it at idle speed.

2. Listen for the sound of the intake air leak.

3. Check PCV hose connection.
Is intake air leak detected?

YES

>> Discover air leak location and repair.

NO

>> GO TO 2.

2.

CHECK FOR EXHAUST SYSTEM CLOGGING

Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
Is the inspection result normal?

YES-1 >> With CONSULT-III: GO TO 3.

YES-2 >> Without CONSULT-III: GO TO 4.

NO

>> Repair or replace it.

3.

PERFORM POWER BALANCE TEST

With CONSULT-III

1. Start engine.

2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-III.

3. Make sure 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 engine idle.

Engine speed

Engine speed in the freeze frame data 

± 400 rpm

Vehicle speed

Vehicle speed in the freeze frame data 

± 10 km/h (6 MPH)

Basic fuel schedule

Basic fuel schedule in freeze frame data 

× (1 ± 0.1)

Engine coolant temperature (T) 
condition

When the freeze frame data shows lower than 70 

°C (158 °F),

T should be lower than 70 

°C (158 °F).

When the freeze frame data shows higher than or equal to 70 

°C (158 °F),

T should be higher than or equal to 70 

°C (158 °F).

Engine speed

Time

Around 1,000 rpm

Approximately 10 minutes

Around 2,000 rpm

Approximately 5 minutes

More than 3,000 rpm

Approximately 3.5 minutes

EC-778

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0300, P0301, P0302, P0303, P0304 MISFIRE

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-957, "Component Inspection"

.

5.

CHECK FUNCTION OF IGNITION COIL-I

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-III to release fuel pressure, or fuel pressure applies again during the following pro-

cedure.

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 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 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 spark plug and the ignition coil

within 50 cm (19.7 in). Be careful not to get an electrical

shock while checking, because the electrical discharge

voltage becomes 20kV or more.

• It might cause to damage the ignition 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 spark 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-II

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?

YES

>> GO TO 7.

NO

>> Check ignition coil, power transistor and their circuits. Refer to 

EC-963, "Component Function

Check"

.

Clicking noise should be heard.

PBIB3332E

Spark should be generated.

JMBIA0066GB

Spark should be generated.

P0300, P0301, P0302, P0303, P0304 MISFIRE

EC-779

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

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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-99, "Standard and Limit"

.

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 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-99, "Standard

and Limit"

.

9.

CHECK COMPRESSION PRESSURE

Check compression pressure. Refer to 

EM-23, "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. Check fuel pressure. Refer to 

EC-1038, "Inspection"

.

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”.

NO

>> Repair or replace.

12.

CHECK IGNITION TIMING

Check the following items. Refer to 

EC-560, "BASIC INSPECTION : Special Repair Requirement"

.

For specification, refer to

EC-1043, "Ignition Timing"

 .

Is the inspection result normal?

YES

>> GO TO 13.

NO

>> Follow the 

EC-560, "BASIC INSPECTION : Special Repair Requirement"

.

13.

CHECK A/F SENSOR 1 INPUT 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.

SEF156I

Spark should be generated.

EC-780

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0300, P0301, P0302, P0303, P0304 MISFIRE

5. Check the continuity between A/F sensor 1 harness connector or ECM harness connector and ground.

6. Also check harness for short to power.
Is the inspection result normal?

YES

>> GO TO 14.

NO

>> Repair open circuit or short to ground or short to power in harness or connectors.

14.

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-686, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 15.

NO

>> Replace A/F sensor 1.

15.

CHECK MASS AIR FLOW SENSOR

With CONSULT-III

Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.

For specification, refer to 

EC-1043, "Mass Air Flow Sensor"

.

With GST

Check mass air flow sensor signal in Service $01 with GST.

For specification, refer to 

EC-1043, "Mass Air Flow Sensor"

.

Is the measurement value within the specification?

YES

>> GO TO 16.

NO

>> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or

ground. Refer to 

EC-693, "DTC Logic"

.

16.

CHECK SYMPTOM TABLE

Check items on the rough idle symptom in 

EC-1027, "Symptom Table"

.

Is the inspection result normal?

YES

>> GO TO 17.

NO

>> Repair or replace.

17.

ERASE THE 1ST TRIP DTC

Some tests may cause a 1st trip DTC to be set.

Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to 

EC-641, "Diagnosis Descrip-

tion"

.

>> GO TO 18.

18.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

A/F sensor 1

ECM

Continuity

Connector Terminal Connector Terminal

F44

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Existed

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A/F sensor 1

ECM

Ground

Continuity

Connector Terminal Connector Terminal

F44

1

F13

45

Ground Not existed

2

49