A/T Models Except ULEV

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

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

OK or NG 

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

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.

1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector and ECM harness connector.
   Fig 2: Locating Air Fuel Ratio Sensor 1 Harness Connector

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Check harness continuity between ECM terminals and A/F sensor 1 terminals as listed in the A/F SENSOR 1 & ECM TERMINAL REFERENCE  table.

   Refer to WIRING DIAGRAM .

   A/F SENSOR 1 & ECM TERMINAL REFERENCE
   
   

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

   1. 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 .

   1. Continuity should not exist. 
5. Also check harness for short to ground and 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.
   1. 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 (Refer to FUEL INJECTOR AND FUEL TUBE .)
• 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.
   1. at idling : 1.4 - 4.0 g.m/sec 
   2. at 2, 500 rpm : 5.0 - 10.0 g.m/sec 

With GST 

1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
   1. at idling : 1.4 - 4.0 g.m/sec 
   2. at 2, 500 rpm : 5.0 - 10.0 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 ground. Refer to "DTC P0101 MAF SENSOR ".

With CONSULT-II 

1. Start engine.
2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-II.
   Fig 3: ACTIVE TEST, POWER BALANCE - CONSULT-II Display Screen

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT-II 

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

   Clicking noise should be heard. 

Fig 4: Listening To Injector Operating Sound

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. Remove injector assembly. Refer to FUEL INJECTOR AND FUEL TUBE .

   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.

   The injector harness connectors should remain connected.

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.

Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

1. : INSPECTION END