Diagnostic Procedure

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

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

OK or NG 

OK: GO TO  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 

OK: GO TO  3.

NG: Repair or replace.

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

   Refer to WIRING DIAGRAM .

   TERMINALS & SENSORS CONTINUITY CHART
   
   

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

   Fig 2: Checking Harness Continuity Between ECM Terminals And A/F Sensor 1 Terminals

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

   Continuity should exist  .

5. 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  .

6. Also check harness for 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.

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 

OK: GO TO  6.

NG: GO TO  5.

Check the following.

• Fuel pump and circuit. Refer to "FUEL PUMP ".
• Fuel pressure regulator
• Fuel lines.
• Fuel filter for clogging

: 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: 1.4 - 4.0 g.m/sec 

   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.

   at idling: 1.4 - 4.0 g.m/sec 

   at 2, 500 rpm: 5.0 - 10.0 g.m/sec 

OK or NG 

OK: GO TO  7.

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.
3. Make sure that each circuit produces a momentary engine speed drop.
   Fig 3: Consult-II ACTIVE TEST Display Screen

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

Without CONSULT-II 

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

   Clicking noise should be heard  .

Fig 4: Checking Fuel Injector For Audible Clicking

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

OK or NG 

OK: GO TO  8.

NG: Perform trouble diagnosis for FUEL INJECTOR "FUEL 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 fuel injector with fuel tube assembly. Refer to "FUEL INJECTOR AND FUEL TUBE ".

   Keep fuel hose and all fuel injectors connected to fuel tube. The fuel injector harness connectors should remain connected.

: GO TO  9.

1. Disconnect all ignition coil harness connectors.
2. Place pans or saucers under each fuel injector.
3. Crank engine for about 3 seconds. Make sure that fuel sprays out from fuel injectors.

   Fuel should be sprayed evenly for each cylinder  .

Fig 5: Checking Fuel Injectors Spray
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

OK: GO TO  10.

NG: Replace fuel injectors from which fuel does not spray out. Always replace O-ring with new one.

Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

: INSPECTION END