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.

Listen for an intake air leak after the mass air flow sensor.

OK or NG 

OK : GO TO 3.

NG : Repair or replace.

1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector (1) (2).
   Fig 2: Disconnecting Corresponding A/F Sensor 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 .
   TERMINAL WIRE COLOR ITEM CONDITION CHART
   
   

   Bank 1	A/F sensor 1 terminal	ECM terminal
   	1	16
   	2	75
   	5	35
   	6	56
   Bank 2	1	76
   	2	77
   	5	57
   	6	58

   Continuity should exist. 

5. Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .
   TERMINAL WIRE COLOR ITEM CONDITION CHART
   
   

   Bank 1		Bank 2
   A/F sensor 1 terminal	ECM terminal	A/F sensor 1 terminal	ECM terminal
   1	16	1	76
   2	75	2	77
   5	35	5	57
   6	56	6	58

   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 (With CONSULT-II) : GO TO  6.

OK (Without CONSULT-II) : GO TO  7.

NG : GO TO 5.

Check the following.

• Fuel pump and circuit (Refer to, , "FUEL PUMP ".)
• Fuel pressure regulator (Refer to , "FUEL PRESSURE CHECK ".)

  : Repair or replace.

With CONSULT-II 

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

   2.0 - 6.0 g.m/sec: at idling 

   7.0 - 20.0 g.m/sec: at 2, 500 rpm 

OK or NG 

OK : GO TO  8.

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 GST 

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

   2.0 - 6.0 g.m/sec: at idling 

   7.0 - 20.0 g.m/sec: at 2, 500 rpm 

OK or NG 

OK (P0172) : GO TO  9.

OK (P0175) : GO TO  11.

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.

OK or NG 

OK : GO TO  12.

NG : Perform trouble diagnosis for FUEL INJECTOR CIRCUIT, refer to , "FUEL INJECTOR ".

Without CONSULT-II 

1. Stop engine.
2. Disconnect harness connector F44 (2), F101 (3)
3. Turn ignition switch ON.
   • : Vehicle front
   • 1: Intake manifold collector
     Fig 4: Disconnecting Harness Connector

     Courtesy of NISSAN MOTOR CO., U.S.A.
4. Check voltage between harness connector F44 terminal 5 and ground with CONSULT-II or tester.

   Voltage: Battery voltage 

5. Turn ignition switch OFF.
6. Disconnect ECM harness connector.
7. Check harness continuity between harness connector F44 terminal and ECM terminal as follows.

   Refer to WIRING DIAGRAM .

   F44 CONNECTOR AND ECM TERMINALS
   
   

   Cylinder	Harness connector F44 terminal	ECM terminal
   1	6	23
   3	2	22
   5	1	21

   Fig 5: Checking Voltage Between Harness Connector F44 Terminal 5 And Ground

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

   Continuity should exist. 

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

OK or NG 

OK : GO TO 10.

NG : Perform trouble diagnosis for FUEL INJECTOR CIRCUIT, refer to , "FUEL INJECTOR ".

Provide battery voltage between harness connector F101 as follows and then interrupt it. Listen to each fuel injector operating sound.

Fig 6: Checking Function Of Fuel Injector

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

Operating sound should exist. 

OK or NG 

OK : GO TO  12.

NG : Perform trouble diagnosis for FUEL INJECTOR CIRCUIT, refer to , "FUEL INJECTOR ".

1. Start engine.
2. Listen to fuel injectors No. 2, No. 4, No. 6 operating sound.

   Clicking noise should exist. 

OK or NG 

OK : GO TO 12.

NG : Perform trouble diagnosis for FUEL INJECTOR CIRCUIT, refer to , "FUEL INJECTOR ".

Fig 7: Checking Fuel Injector For Audible Clicking

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

1. Remove fuel injector assembly. Refer to , "FUEL INJECTOR AND FUEL TUBE ".

   Keep fuel hose and all fuel injectors connected to fuel injector gallery.

2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all fuel injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each fuel injectors.
6. Crank engine for about 3 seconds.

   Make sure fuel does not drip from fuel injector.

OK or NG 

OK (Does not drip.) : GO TO 13.

NG (Drips.) : Replace the fuel injectors from which fuel is dripping. Always replace O-ring with new one.

Refer to , "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

: INSPECTION END