Diagnostic 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 MOTOR CO., U.S.A.

OK or NG 

1. OK : GO TO 2.
2. NG : Repair or replace.

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

OK or NG 

1. OK : GO TO 3.
2. NG : Repair or replace.

1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector and ECM harness connector.
3. Check harness continuity between ECM terminals and A/F sensor 1 terminals as follows.

   Refer to WIRING DIAGRAM .

   A/F SENSOR AND ECM TERMINALS REFERENCE
   
   

   A/F sensor 1	ECM terminal
   1	16
   2	75
   5	35
   6	56

   Fig 2: Disconnecting A/F Sensor 1 Harness Connector And ECM Harness Connector

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

   Continuity should exist  .

4. Check harness continuity between ECM terminals 16, 35, 56, 75 and ground, or A/F sensor 1 terminals 1, 2, 5, 6 and ground.

   Refer to WIRING DIAGRAM .

   Continuity should not exist  .

5. Also check harness for short to power.

OK or NG 

1. OK : GO TO 4.
2. NG : Repair open circuit or short to ground or short to power in harness or connectors.

1. Release fuel pressure to zero. Refer to "FUEL PRESSURE RELEASE ".
2. Install fuel pressure gauge and check fuel pressure. Refer to "FUEL PRESSURE CHECK ".

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

OK or NG 

1. OK : GO TO  6.
2. NG : GO TO 5.

Check the following.

• Fuel pump and circuit (Refer to "FUEL PUMP CIRCUIT ".)
• Fuel pressure regulator (Refer to "FUEL PRESSURE CHECK ".)
• Fuel lines
• Fuel filter for clogging

1. : Repair or replace.

With CONSULT-II 

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

   At idling: 1.0 - 4.0 g.m/sec 

   At 2, 500 RPM: 4.0 - 12.0 g.m/sec 

With GST 

1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.

   At idling: 1.0 - 4.0 g.m/sec 

   At 2, 500 RPM: 4.0 - 12.0 g.m/sec 

OK or NG 

1. OK : GO TO 7.
2. NG : Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to "DTC P0102, P0103 MAF SENSOR ".

With CONSULT-II 

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

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

Without CONSULT-II 

1. Start engine.
2. Listen to each injector operating sound.

   Clicking noise should be heard  .

   Fig 4: Checking Injector Operating Sounds

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

OK or NG 

1. OK : GO TO 8.
2. NG : Perform trouble diagnosis for "INJECTOR CIRCUIT ".

1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch OFF.
3. Disconnect injector harness connectors.
4. Remove injector gallery assembly. Refer to "FUEL INJECTOR AND FUEL TUBE ".

   Keep fuel hose and all injectors connected to injector gallery.

   The injector harness connectors should remain connected.

5. Disconnect all ignition coil harness connectors.
6. Prepare pans or saucers under each injector.
7. Crank engine for about 3 seconds. Make sure that fuel sprays out from injectors.

   Fuel should be sprayed evenly for each injector  .

OK or NG 

1. OK : GO TO 9.
2. NG : Replace injectors from which fuel does not spray out. Always replace O-ring with new ones.
   Fig 5: Identifying Fuel Injector

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

Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

1. : INSPECTION END