Diagnosis Procedure

1. Activate "INSPECTION MODE 1 " to start engine.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
   Fig 1: Checking Exhaust Gas For Leakage

   Courtesy of NISSAN MOTOR CO., U.S.A.

Is exhaust gas leak detected? 

YES : Repair or replace.

NO : GO TO 2.

1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.

Intake air leak detected? 

YES : Repair or replace.

NO : GO TO 3.

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.
   TERMINALS CONTINUITY REFERENCE
   
   

   A/F sensor 1		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   F44	1	F14	45	Existed
   	2		49

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

   A/F sensor 1		ECM		Ground	Continuity
   Connector	Terminal	Connector	Terminal
   F44	1	F14	45	Ground	Not existed
   	2		49

6. Also check harness for short to power.

Is the inspection result normal? 

YES : GO TO 4.

NO : Repair open circuit or short to ground or short to power in harness or connectors.

1. Release fuel pressure to zero. Refer to "INSPECTION ".
2. Install fuel pressure gauge and check fuel pressure. Refer to "INSPECTION ".

   At idling: Approximately 350 kPa (3.57 kg/cm ²  , 51 psi) 

Is the inspection result normal? 

YES : GO TO  6.

NO : GO TO 5.

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

With CONSULT-III 

1. Install all removed parts.
2. Check "MASS AIR FLOW" in "DATA MONITOR" mode with CONSULT-III.
3. For specification, refer to "MASS AIR FLOW SENSOR ".

With GST 

1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
3. For specification, refer to "MASS AIR FLOW SENSOR ".

Is the measurement value within the specification? 

YES : GO TO 7.

NO : Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to "DTC LOGIC ".

With CONSULT-III 

1. Turn ignition switch ON (READY).
2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT-III 

1. Activate "INSPECTION MODE 1 " to start engine.
2. Listen to each fuel injector operating sound.

   Clicking noise should be heard. 

   Fig 2: Checking Fuel Injector

   Courtesy of NISSAN MOTOR CO., U.S.A.

Is the inspection result normal? 

YES : GO TO 8.

NO : Perform trouble diagnosis for FUEL INJECTOR, refer to "DIAGNOSIS PROCEDURE ".

1. Turn ignition switch OFF.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all fuel injector harness connectors.
4. Remove fuel tube assembly. Refer to "REMOVAL AND INSTALLATION ".

   Keep fuel hose and all fuel injectors connected to fuel tube.

5. Disconnect all ignition coil harness connectors.
6. Prepare pans or saucers under each fuel injector.
7. Turn ignition switch ON (READY).
8. Depress the accelerator pedal to crank engine.
   NOTE: If step  8 performed, a certain DTC may be detected.

   Fuel should be sprayed evenly for each fuel injector. 

   Fig 3: Depressing Accelerator Pedal To Crank Engine

   Courtesy of NISSAN MOTOR CO., U.S.A.

Is the inspection result normal? 

YES : GO TO 9.

NO : Replace fuel injectors from which fuel does not spray out. Always replace O-ring with new ones.

Refer to "INTERMITTENT INCIDENT ".

INSPECTION END