Nissan Frontier. Manual - part 540

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

EC-731

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Restart engine and let it idle for about 15 minutes.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to

EC-731, "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. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
d. 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.

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

WITH GST

Follow the procedure “WITH CONSULT” above.

Diagnosis Procedure

INFOID:0000000009481388

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

>> GO TO 2.

>> Discover air leak location and repair.

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)>>GO TO 3.

OK (Without CONSULT)>>GO TO 4.

>> Repair or replace it.

PERFORM POWER BALANCE TEST

With CONSULT

Engine speed

Engine speed in the freeze frame data

± 400 rpm

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-732

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

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

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.

>> GO TO 10.

CHECK FUNCTION OF FUEL INJECTOR-I

Stop engine.

1. Disconnect harness connector F44 (3), F201 (1)

2. Turn ignition switch ON.

3. Check voltage between harness connector F44 terminal 3 and ground with CONSULT or tester.

4. Turn ignition switch OFF.

5. Disconnect ECM harness connector.

6. Check harness continuity between harness connector F44 and ECM as follows.

Refer to Wiring Diagram.

7. Also check harness for short to ground and short to power.
OK or NG

>> GO TO 5.

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-928, "Diagnosis Procedure"

CHECK FUNCTION OF FUEL INJECTOR-II

Provide battery voltage between harness connector F201 as follows and then interrupt it. Listen to each fuel

injector operating sound.

OK or NG

>> GO TO 6.

: Vacuum tank

: Front

AWBIA0686ZZ

Voltage: Battery voltage

Cylinder

Harness connector F44

terminal

ECM terminal

Continuity should exist.

Cylinder

Harness connector F201 terminal

(+)

(–)

Operating sound should exist.

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

EC-733

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-928, "Diagnosis Procedure"

CHECK FUNCTION OF FUEL INJECTOR-III

1. Reconnect all harness connector disconnected.

2. Start engine.

3. Listen to fuel injectors No. 2, No. 4, No.6 operating sound.

OK or NG

>> GO TO 7.

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-928, "Diagnosis Procedure"

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 (No.48) 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 procedure.

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 electri-

cal discharge from the ignition coils.

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

checked.

8. Crank engine for five 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 three seconds, and check whether spark

is generated between the spark plug and the grounded metal

portion.

CAUTION:

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

50cm (19.7 in) each other. Be careful not to get an electri-

cal shock while checking, because the electrical dis-

charge voltage becomes 20 kV or more.

• It might cause to 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), the spark might be generated even if the coil is mal-

functioning.

OK or NG

>> GO TO 11.

>> GO TO 8.

CHECK FUNCTION OF IGNITION COIL-II

1. Turn ignition switch OFF.

2. Disconnect spark plug and connect a known-good spark plug.

Clicking noise should exist.

PBIB1986E

Spark should be generated.

BBIA0534E

JMBIA0066GB

EC-734

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

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

3. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug

and the grounded metal portion.

OK or NG

>> GO TO 9.

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

EC-935, "Diagnosis Procedure"

CHECK SPARK PLUG

Check the initial spark plug for fouling, etc.
OK or NG

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

spark plug type, refer to

EM-132, "Removal and Installa-

tion"

>> 1. Repair or clean spark plug.

2. GO TO 10.

10.

CHECK FUNCTION OF IGNITION COIL-III

1. Reconnect the initial spark plugs.

2. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug

and the grounded portion.

OK or NG

>> INSPECTION END

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

EM-132, "Removal

and Installation"

11.

CHECK COMPRESSION PRESSURE

Check compression pressure. Refer to

EM-138, "Compression Pressure"

OK or NG

>> GO TO 12.

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

12.

CHECK FUEL PRESSURE

1. Install all removed parts.

2. Release fuel pressure to zero. Refer to

EC-959, "Fuel Pressure Check"

3. Install fuel pressure gauge and check fuel pressure. Refer to

EC-959, "Fuel Pressure Check"

OK or NG

>> GO TO 14.

>> GO TO 13.

13.

DETECT MALFUNCTIONING PART

Check the following.

• Fuel pump and circuit (Refer to

EC-932, "Description"

• Fuel pressure regulator (Refer to

EC-959, "Fuel Pressure Check"

• Fuel lines

• Fuel filter for clogging

>> Repair or replace.

Spark should be generated.

SEF156I

Spark should be generated.

At idle: Approx. 350 kPa (3.57 kg/cm

, 51 psi)

Content .. 538 539 540 541 ..