Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Infiniti >> 2006 >> G35 x >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0130 To P0430 (Sedan) >> DTC P0172, P0175 Fuel Injection System Function >> Diagnostic Procedure

Diagnostic Procedure

  1. CHECK EXHAUST GAS LEAK 
    1. Start engine and run it at idle.
    2. Listen for an exhaust gas leak before three way catalyst 1.
      Fig 1: Identifying Exhaust Gas Leak Before Three Way Catalyst 1
      G04119894Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG: Repair or replace.
  2. 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.
  3. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect corresponding A/F sensor 1 harness connector.
      Fig 2: Identifying Corresponding A/F Sensor 1 Harness Connector
      G04119895Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Disconnect ECM harness connector.
    4. Check harness continuity between the following terminals.

      Refer to WIRING DIAGRAM .

      TERMINALS CONTINUITY REFERENCE

      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 .

      TERMINALS CONTINUITY REFERENCE

      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 

    1. OK: GO TO 4.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  4. 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: Approximately 350 kPa (3.57 kg/cm2, 51 psi) 

    OK or NG 

    1. OK: GO TO  6.
    2. NG: GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

  6. 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.

      2.0 - 6.0 g.m/sec: at idling 

      7.0 - 20.0 g.m/sec: at 2, 500 RPM 

    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 

    1. OK (With CONSULT-II): GO TO 7.
    2. OK (Without CONSULT-II): GO TO  8.
    3. NG: Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or ground. Refer to "DTC P0101 MAF SENSOR ".
  7. CHECK FUNCTION OF FUEL INJECTOR 

    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.
      4. Fig 3: Consult-II ACTIVE TEST Display Screen
      G04080452Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  10.
    2. NG: Perform trouble diagnosis for FUEL INJECTOR, "FUEL INJECTOR ".
  8. CHECK FUNCTION OF FUEL INJECTOR-I 

    Without CONSULT-II 

    1. Stop engine.
    2. Disconnect harness connector F33, F221
    3. Turn ignition switch ON.
      Fig 4: Identifying Harness Connector F33, F221
      G04119897Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between harness connector F33 terminal 5 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

      Fig 5: Identifying Voltage Between Harness Connector Terminal 5 And Ground
      G04073991Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Turn ignition switch OFF.
    6. Disconnect ECM harness connector.
    7. Check harness continuity between harness connector F33 and ECM as follows.

      Refer to WIRING DIAGRAM .

      TERMINALS CONTINUITY REFERENCE

      Cylinder Harness connector F33 terminal ECM terminal
      1 6 23
      2 4 42
      3 2 22
      4 3 41
      5 1 21
      6 7 40

      Continuity should exist. 

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

    OK or NG 

    1. OK: GO TO 9.
    2. NG: Perform trouble diagnosis for FUEL INJECTOR, refer to "FUEL INJECTOR ".
  9. CHECK FUNCTION OF FUEL INJECTOR-II 

    Provide battery voltage between harness connector F221 as follows and then interrupt it. Listen to each fuel injector operating sound.

    TERMINALS VOLTAGE REFERENCE

    Cylinder Harness connector F221 terminal
    (+) (-)
    1 5 6
    2 4
    3 2
    4 3
    5 1
    6 7

    Operating sound should exist. 

    Fig 6: Identifying Function Of Fuel Injector-II
    G04119899Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 10.
    2. NG: Perform trouble diagnosis for FUEL INJECTOR, refer to "FUEL INJECTOR ".
  10. CHECK FUEL INJECTOR 
    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. Reconnect all harness connectors disconnected.
    4. Disconnect all fuel injector harness connectors.
    5. Disconnect all ignition coil harness connectors.
    6. Prepare pans or saucers under each fuel injectors.
    7. Crank engine for about 3 seconds.

      Make sure fuel does not drip from fuel injector.

    OK or NG 

    1. OK (Does not drip.): GO TO 11.
    2. NG (Drips.): Replace the fuel injectors from which fuel is dripping. Always replace O-ring with new one.
  11. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    INSPECTION END 

scientia non olet · About Mike's Workshop Manuals