Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.

CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
  
  Fig 1: Listening For An Exhaust Gas Leak
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  OK or NG
  1. OK: GO TO 2.
  2. NG: Repair or replace.
CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.

OK or NG
1. OK: GO TO 3.
2. NG: Repair or replace.
CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
  
  Fig 2: Disconnecting Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
  Refer to WIRING DIAGRAM .
  
  Fig 3: Identifying Harness Continuity Test Terminals
  Courtesy of NISSAN MOTOR CO., U.S.A.
  1. Continuity should exist.
5. Check harness continuity between the following terminals and ground.
  Refer to WIRING DIAGRAM .
  
  Fig 4: Identifying Harness Short To Ground Test Terminals
  Courtesy of NISSAN MOTOR CO., U.S.A.
  1. Continuity should not exist.
6. 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.
CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to FUEL PRESSURE RELEASE in BASIC DIAGNOSTIC PROCEDURES - TITAN article.
2. Install fuel pressure gauge and check fuel pressure. Refer to FUEL PRESSURE CHECK in BASIC DIAGNOSTIC PROCEDURES - TITAN article.
  1. At idling: 350 kPa (3.57 kg/cm ², 51 psi)
  OK or NG
  1. OK: GO TO 6.
  2. NG: GO TO 5.
DETECT MALFUNCTIONING PART
Check the following.
- Fuel pump and circuit (Refer to FUEL PUMP CIRCUIT ) in SYSTEM & COMPONENT TESTING - TITAN article.
- Fuel pressure regulator. Refer to FUEL PRESSURE CHECK in BASIC DIAGNOSTIC PROCEDURES - TITAN article.
1. Repair or replace.
CHECK MASS AIR FLOW SENSOR
With CONSULT-II
1. Install all removed parts.
2. Check "MASS AIR FLOW" in "DATA MONITOR" mode with CONSULT-II.
  1. 3.0 - 9.0 g.m/sec: at idling
  2. 9.0 - 28.0 g.m/sec: at 2,500 RPM
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in MODE 1 with GST.
  1. 3.0 - 9.0 g.m/sec: at idling
  2. 9.0 - 28.0 g.m/sec: at 2,500 RPM
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 engine grounds. Refer to DTC P0101 MAF SENSOR .
CHECK FUNCTION OF INJECTORS
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 5: Performing "POWER BALANCE" In "ACTIVE TEST" Mode
  Courtesy of NISSAN MOTOR CO., U.S.A.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
  1. Clicking noise should be heard.
  Fig 6: Listening To Each Injector
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 8.
2. NG: Perform trouble diagnosis for INJECTOR CIRCUIT in SYSTEM & COMPONENT TESTING - TITAN article.
CHECK INJECTOR
1. Remove injector assembly. Refer to FUEL INJECTOR AND FUEL TUBE in ENGINE MECHANICAL - TITAN - 5.6L article.
  Keep fuel hose and all injectors connected to injector gallery.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injectors.
6. Crank engine for about 3 seconds.
  Make sure fuel does not drip from injector.
  
  OK or NG
  1. OK (Does not drip.): GO TO 9.
  2. NG (Drips.): Replace the injectors from which fuel is dripping. Always replace O-ring with NEW one.
CHECK INTERMITTENT INCIDENT
Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .
1. INSPECTION END