Infiniti FX35, FX50 (S51). Manual - part 831

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE

EC-865

< DTC/CIRCUIT DIAGNOSIS >

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5.

Restart engine and let it idle for about 15 minutes.

6.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-865, "Diagnosis Procedure"

.

NO

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE-II

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.

4.

Start engine and drive the vehicle under 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.
Similar conditions to (1st trip) Freeze Frame Data mean that the following conditions 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.

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

5.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-865, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005237346

1.

CHECK FOR INTAKE AIR LEAKAGE AND PCV HOSE

1.

Start engine and run it at idle speed.

2.

Listen for the sound of the intake air leakage.

3.

Check PCV hose connection.

Is intake air leakage detected?

YES

>> Discover air leakage 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 malfunctioning part.

3.

PERFORM POWER BALANCE TEST

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)

Base fuel schedule

Base fuel schedule in the 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-866

< DTC/CIRCUIT DIAGNOSIS >

[VK50VE]

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE

 With CONSULT-III

1.

Start engine.

2.

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

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-I

1.

Start engine and let it idle.

2.

Listen to each fuel injector operation.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-1103, "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 (1) in IPDM E/R (2) to release fuel pres-
sure.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pres-
sure applies again during the following procedure.

3.

Start engine.

4.

After engine stalls, crank it 2 or 3 times to release all fuel pres-
sure.

5.

Turn ignition switch OFF.

6.

Remove all ignition coil harness connectors to avoid the electri-
cal 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:

• Never place the spark plug and the ignition coil within 50

cm (19.7 in) each other. Be careful not to get an electrical
shock 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?

Clicking sound should be heard.

PBIB3332E

Spark should be generated.

JMBIA1552ZZ

JMBIA0066GB

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE

EC-867

< DTC/CIRCUIT DIAGNOSIS >

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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.

3.

Crank engine for approximately 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-1114, "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-282, "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 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-282, "Spark

Plug"

.

9.

CHECK COMPRESSION PRESSURE

Check compression pressure. Refer to 

EM-173, "Inspection"

.

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-1236, "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 malfunctioning part.

12.

CHECK IDLE SPEED AND IGNITION TIMING

Spark should be generated.

SEF156I

Spark should be generated.

EC-868

< DTC/CIRCUIT DIAGNOSIS >

[VK50VE]

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE

Check idle speed and ignition timing.
For procedure, refer to 

EC-576, "BASIC INSPECTION : Special Repair Requirement"

.

For specification, refer to 

EC-1241, "Idle Speed"

 and 

EC-1241, "Ignition Timing"

.

Is the inspection result normal?

YES

>> GO TO 13.

NO

>> Follow the 

EC-576, "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.

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 14.

NO

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

14.

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-762, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 15.

NO

>> Replace malfunctioning A/F sensor 1.

15.

CHECK MASS AIR FLOW SENSOR

 With CONSULT-III

Check mass air flow sensor signal in “DATA MONITOR” mode with CONSULT-III.
For specification, refer to 

EC-1241, "Mass Air Flow Sensor"

.

 With GST

Check mass air flow sensor signal in Service $01 with GST.
For specification, refer to 

EC-1241, "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-773, "Diagnosis Procedure"

.

16.

CHECK SYMPTOM MATRIX CHART

Check items on the rough idle symptom in 

EC-1223, "Symptom Table"

.

A/F sensor 1

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

1

F67

1

F111

81

Existed

2

82

2

F68

1

85

2

86

A/F sensor 1

ECM

Ground

Continuity

Bank

Connector

Terminal

Connector

Terminal

1

F67

1

F111

81

Ground

Not existed

2

82

2

F68

1

85

2

86