PR25DD engine

Check the following.

• Connection condition of the ground F9 and F15.
• Connection condition of the ground harness between engine assembly and vehicle body (If equipped).

Is the inspection result normal?

YES

GO TO 2.

NO

Repair or replace error-detected parts.

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 3.

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

Is the inspection result normal?

YES

With CONSULT: GO TO 4.

YES

Without CONSULT: GO TO 5.

NO

Repair or replace it.

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.

Is the inspection result normal?

YES

GO TO 10.

NO

GO TO 5.

1. Start engine and let engine idle.
2. Listen to each fuel injector operating sound.

   Courtesy of NISSAN NORTH AMERICA, INC.

   Clicking noise should be heard.

Is the inspection result normal?

YES

GO TO 6.

NO

Perform trouble diagnosis for FUEL INJECTOR. Refer to Diagnosis Procedure .

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 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 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.

    Courtesy of NISSAN NORTH AMERICA, INC.

11. Crank engine for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal portion.

    Spark should be generated.

    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 20 kV 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 malfunctioning.

Is the inspection result normal?

YES

GO TO 10.

NO

GO TO 7.

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.

   Spark should be generated.

Is the inspection result normal?

YES

GO TO 8.

NO

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

Check the initial spark plug for fouling, etc.

Courtesy of NISSAN NORTH AMERICA, INC.

Is the inspection result normal?

YES

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

NO

Repair or clean spark plug. Then GO TO 9.

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.

   Spark should be generated.

Is the inspection result normal?

YES

INSPECTION END

NO

Replace spark plug(s) with standard type one(s). For spark plug type. Refer to Inspection .

Check compression pressure. Refer to Work Procedure .

Is the inspection result normal?

YES

GO TO 11.

NO

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

1. Install all removed parts.
2. Release fuel pressure to zero.
3. Install fuel pressure gauge and check fuel pressure. Refer to Work Procedure .

   At idling: Approximately 500 kPa (5.1 kg/cm 2 , 72.5 psi)

Is the inspection result normal?

YES

GO TO 13.

NO

GO TO 12.

Check fuel hoses and fuel tubes for clogging.

Is the inspection result normal?

YES

Replace "fuel filter and fuel pump assembly". Refer to Removal & Installation (AWD) or Removal & Installation (FWD).

NO

Repair or replace.

Check the following items.

For procedure, refer to Work Procedure .

For specification, refer to IGNITION TIMING : Service Datai .

Is the inspection result normal?

YES

GO TO 14.

NO

Follow the Work Procedure .

1. Turn ignition switch OFF.
2. Disconnect 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.

   +		-		Continuity
   A/F sensor 1		ECM
   Connector	Terminal	Connector	Terminal
   F44	1	F90	86	Existed
   	2		88

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

   +		-	Continuity
   A/F sensor 1
   Connector	Terminal
   F44	1	Ground	Not existed
   	2

   +		-	Continuity
   ECM
   Connector	Terminal
   F90	86	Ground	Not existed
   	88

6. Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 15.

NO

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

Check the A/F sensor 1 heater. Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO 16.

NO

Replace A/F sensor 1. Refer to Exploded View .

With CONSULT

Check "MASS AIRFLOW" in "DATA MONITOR" mode of "ENGINE" using CONSULT.

With GST

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

Is the measurement value within the specification?

YES

GO TO 17.

NO

Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or ground. Refer to Component Inspection .

Check items on the rough idle symptom in Refer to Symptom Table .

Is the inspection result normal?

YES

GO TO 18.

NO

Repair or replace error-detected parts.

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 Diagnosis Description .

GO TO 19.

Refer to Inspection .

INSPECTION END