Diagnostic Procedure

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: 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.
CHECK FOR INTAKE AIR LEAK AND PCV HOSE
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.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 CIRCUIT FOR OPEN AND SHORT

Turn ignition switch OFF.
Disconnect A/F sensor 1 harness connector and ECM harness connector.

Fig 2: Checking Air Fuel Ratio (A/F) Sensor 1 Circuit For Open & Short
Courtesy of NISSAN MOTOR CO., U.S.A.

Check harness continuity between ECM terminals and A/F sensor 1 terminals as follows.

A/F SENSOR 1 AND ECM TERMINAL

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

Continuity should exist.

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.
Also check harness for short to ground and short to power.

OK or NG

OK : GO TO 4.
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 ".
2. Install fuel pressure gauge and check fuel pressure. Refer to "FUEL PRESSURE CHECK ".
  At idling: 350 kPa (3.57 kg/cm ² , 51 psi)
OK or NG
1. OK : GO TO 5.
2. NG : Follow the instruction of FUEL PRESSURE CHECK.
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.
  at idling: 1.0 - 4.0 g.m/sec
  
  at 2, 500 RPM: 4.0 - 10.0 g.m/sec
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in MODE 1 with GST.
  at idling: 1.0 - 4.0 g.m/sec
  
  at 2, 500 RPM: 4.0 - 10.0 g.m/sec
OK or NG
1. OK : GO TO 6.
2. NG : Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or engine grounds. Refer to DTC P0101 MAP 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 3: Displaying Active Test
  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 Sound
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 7.
2. NG : Perform trouble diagnosis for "INJECTOR CIRCUIT ".
CHECK INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch OFF.
3. 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.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injector.
6. 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 8.
2. NG : Replace injectors from which fuel does not spray out. Always replace O-ring with new ones.
  
  Fig 5: Checking Injector
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK INTERMITTENT INCIDENT
Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
1. >> INSPECTION END