Infiniti FX35 / FX45. Manual - part 387

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306 MULTIPLE CYLINDER 

MISFIRE, NO. 1 - 6 CYLINDER MISFIRE

EC-309

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

5.

Check 1st trip DTC.

6.

If 1st trip DTC is detected, go to 

EC-309, "Diagnosis Procedure"

.

NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.

a.

Turn ignition switch OFF and wait at least 10 seconds.

b.

Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain
time. Refer to 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 condi-
tions should be satisfied at the same time.

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

 WITH GST

Follow the procedure “WITH CONSULT-III” above.

Diagnosis Procedure

INFOID:0000000001326133

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.

OK or NG

OK

>> GO TO 2.

NG

>> Discover air leak location and repair.

2.

CHECK FOR EXHAUST SYSTEM CLOGGING

Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG

OK (With CONSULT-III)>>GO TO 3.
OK (Without CONSULT-III)>>GO TO 4.
NG

>> Repair or replace it.

3.

PERFORM POWER BALANCE TEST

 With CONSULT-III

1.

Perform “POWER BALANCE” in “ACTIVE TEST” mode.

2.

Is there any cylinder which does not produce a momentary engine speed drop?

Yes or No

Yes

>> GO TO 4.

No

>> GO TO 10.

4.

CHECK FUNCTION OF FUEL INJECTOR-I

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)

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-310

< SERVICE INFORMATION >

[VQ35DE]

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306 MULTIPLE CYLINDER 

MISFIRE, NO. 1 - 6 CYLINDER MISFIRE

 Without CONSULT-III

1.

Stop engine.

2.

Disconnect harness connectors F50, F251

3.

Turn ignition switch ON.

4.

Check voltage between harness connector F50 terminal 5 and
ground.

5.

Turn ignition switch OFF.

6.

Disconnect ECM harness connector.

7.

Check harness continuity between harness connector F50 and
ECM as follows.
Refer to Wiring Diagram.

8.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 5.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to 

EC-552

.

5.

CHECK FUNCTION OF FUEL INJECTOR-II

Provide battery voltage between harness connector F251 as follows
and then interrupt it. Listen to each fuel injector operating sound.

PBIB2624E

Voltage: Battery voltage

Cylinder

Harness connector F50 

terminal

ECM terminal

1

6

23

2

4

42

3

2

22

4

3

41

5

1

21

6

7

40

Continuity should exist.

PBIB2323E

Cylinder

Harness connector F251 terminal

(+)

(–)

1

5

6

2

4

3

2

4

3

5

1

6

7

PBIB2497E

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306 MULTIPLE CYLINDER 

MISFIRE, NO. 1 - 6 CYLINDER MISFIRE

EC-311

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

OK or NG

OK

>> GO TO 6.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to 

EC-552

.

6.

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.

Reconnect all harness connectors disconnected.

3.

Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pres-
sure applies again during the following procedure.

4.

Start engine.

5.

After engine stalls, crank it two or three times to release all fuel
pressure.

6.

Turn ignition switch OFF.

7.

Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.

8.

Remove ignition coil and spark plug of the cylinder to be
checked.

9.

Crank engine for 5 seconds or more to remove combustion gas in the cylinder.

10. Connect spark plug and harness connector to ignition coil.
11. Fix ignition coil using a rope etc. with gap of 13 - 17 mm

between the edge of the spark plug and grounded metal portion
as shown in the figure.

12. 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 50cm. 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 is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.

OK or NG

OK

>> GO TO 10.

NG

>> 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 about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.

OK or NG

OK

>> GO TO 8.

NG

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

EC-569

.

8.

CHECK SPARK PLUG

Operating sound should exist.

Spark should be generated.

PBIB1603E

PBIB2325E

Spark should be generated.

EC-312

< SERVICE INFORMATION >

[VQ35DE]

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306 MULTIPLE CYLINDER 

MISFIRE, NO. 1 - 6 CYLINDER MISFIRE

Check the initial spark plug for fouling, etc.

OK or NG

OK

>> Replace spark plug(s) with standard type one(s). For

spark plug type, refer to 

MA-17, "Changing Spark Plugs

(Platinum-Tipped Type)"

.

NG

>> 1.

Repair or clean spark plug.

2.

GO TO 9.

9.

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.

OK or NG

OK

>> INSPECTION END

NG

>> Replace spark plug(s) with standard type one(s). For spark plug type, refer to 

MA-17, "Changing

Spark Plugs (Platinum-Tipped Type)"

.

10.

CHECK COMPRESSION PRESSURE

Check compression pressure. Refer to 

EM-100, "On-Vehicle Service"

.

OK or NG

OK

>> GO TO 11.

NG

>> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.

11.

CHECK FUEL PRESSURE

1.

Install all removed parts.

2.

Release fuel pressure to zero. Refer to 

EC-87, "Fuel Pressure Check"

.

3.

Install fuel pressure gauge and check fuel pressure. Refer to 

EC-87, "Fuel Pressure Check"

.

OK or NG

OK

>> GO TO 13.

NG

>> GO TO 12.

12.

DETECT MALFUNCTIONING PART

Check the following.
• Fuel pump and circuit (Refer to 

EC-558

.)

• Fuel pressure regulator (Refer to 

EC-87, "Fuel Pressure Check"

.)

• Fuel lines (Refer to 

MA-15, "Checking Fuel Line"

.)

• Fuel filter for clogging

>> Repair or replace.

13.

CHECK IGNITION TIMING

Check the following items. Refer to 

EC-80, "Basic Inspection"

.

OK or NG

OK

>> GO TO 14.

SEF156I

Spark should be generated.

At idle: Approximately 350 kPa (3.57 kg/cm

2

, 51 psi)

Items

Specifications

Target idle speed

650 

±

 50 rpm (in P or N position)

Ignition timing

15 

±

 5

°

 BTDC (in P or N position)