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Home >> Nissan-Datsun >> 2003 >> Sentra SE-R, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 2305 (Engine Control System - DTCS P0137 Through P0445) >> DTC P0172, P0175 Fuel Injection System Function >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2006 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.
  1. 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: Inspecting For Exhaust Gas Leaks
      G04191081Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 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 

    OK: GO TO 3.

    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: Disconnecting Corresponding A/F Sensor 1 Harness Connector
      G04173389Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Disconnect ECM harness connector.
    4. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.

      Refer to WIRING DIAGRAM .

      A/F SENSOR 1 TERMINAL AND ECM TERMINAL CONTINUITY

      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 .

      A/F SENSOR 1 TERMINAL AND ECM TERMINAL CONTINUITY

      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.

  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: 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.

  5. DETECT MALFUNCTIONING PART 

    Check the following.

    : Repair or replace.

  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 

    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 .

  7. CHECK MASS AIR FLOW 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 .

  8. 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.
      Fig 3: Consult-II ACTIVE TEST Display Screen
      G04080452Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  12.

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

  9. CHECK FUNCTION OF FUEL INJECTOR-I 

    Without CONSULT-II 

    1. Stop engine.
    2. Disconnect harness connector F44, F101
    3. Turn ignition switch ON.
      Fig 4: Disconnecting Harness Connector F44, F101
      G04173391Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between harness connector F44 terminal 3 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 and ECM as follows.

      Refer to WIRING DIAGRAM .

      Fig 5: Checking Voltage Between Harness Connector F44 Terminal 3 And Ground
      G04173392Courtesy of NISSAN MOTOR CO., U.S.A.
      ECM AND F44 CONNECTOR TERMINALS CONTINUITY

      Cylinder Harness connector F44 terminal ECM terminal
      1 2 23
      3 1 22
      5 4 21

      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, refer to FUEL INJECTOR .

  10. CHECK FUNCTION OF FUEL INJECTOR-II 

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

    FUEL INJECTOR-II FUNCTION INSPECTION

    Cylinder Harness connector F101 terminal
    (+) (-)
    1 3 2
    3 3 1
    5 3 4

    Operating sound should exist. 

    Fig 6: Applying Battery Voltage Between Harness Connector F101
    G04173393Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  12.

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

  11. CHECK FUNCTION OF 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, refer to FUEL INJECTOR .

    Fig 7: Checking Fuel Injector For Audible Clicking
    G04132840Courtesy of NISSAN MOTOR CO., U.S.A.
  12. 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 tube.

    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.

  13. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END 

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