Diagnosis Procedure

1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
   Fig 1: Checking Exhaust Gas Leak

   Courtesy of NISSAN NORTH AMERICA, INC.

   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.

   A/F sensor 1		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   F51	1	F8	49	Existed
   	2		53

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

   A/F sensor 1		Ground	Continuity
   Connector	Terminal
   F51	1	Ground	Not existed
   	2

   ECM		Ground	Continuity
   Connector	Terminal
   F8	49	Ground	Not existed
   	53

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. Check fuel pressure. Refer to "INSPECTION ".

   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". Refer to "EXPLODED VIEW ".

NO >> Repair or replace

With CONSULT 

1. Install all removed parts.
2. Check "MASS AIR FLOW" in "DATA MONITOR" mode with CONSULT.
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 

1. Start engine.
2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT.
3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT 

1. Let engine idle.
2. Listen to each fuel injector operating sound.

   Clicking noise should be heard. 

   Fig 2: Checking Fuel Injector Operating Sound

   Courtesy of NISSAN NORTH AMERICA, INC.

   Is the inspection result normal? 

   YES >> GO TO 8.

   NO >> Perform trouble diagnosis for FUEL INJECTOR, refer to "COMPONENT FUNCTION CHECK ".

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. Crank engine for about 3 seconds.

   Fuel should be sprayed evenly for each fuel injector. 

   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 "EXPLODED VIEW ".

   Fig 3: Checking Fuel Injector Spray

   Courtesy of NISSAN NORTH AMERICA, INC.

Refer to "INTERMITTENT INCIDENT ".

>> INSPECTION END