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Home >> Infiniti >> 2011 >> EX35 Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0130 Through P0445 >> DTC P0420, P0430: Three Way Catalyst Function >> Component Function Check >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK EXHAUST SYSTEM

    Visually check exhaust tubes and muffler for dent.

    Is the inspection result normal? 

    YES: GO TO 2.

    NO: Repair or replace malfunctioning part.

  2. CHECK EXHAUST GAS LEAK
    1. Start engine and run it at idle.
    2. Listen for an exhaust gas leak before the three way catalyst 1.
    Fig 1: Checking Exhaust Gas Leakage
    G07165057Courtesy of NISSAN MOTOR CO., U.S.A.

    Is exhaust gas leak detected? 

    YES: Repair or replace malfunctioning part.

    NO: GO TO 3.

  3. CHECK INTAKE AIR LEAK

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

    Is intake air leak detected? 

    YES: Repair or replace malfunctioning part.

    NO: GO TO 4.

  4. CHECK IDLE SPEED AND IGNITION TIMING

    Check idle speed and ignition timing.

    For procedure, refer to "BASIC INSPECTION : SPECIAL REPAIR REQUIREMENT ".

    For specification, refer to "IDLE SPEED " and "IGNITION TIMING ".

    Is the inspection result normal? 

    YES: GO TO 5.

    NO: Follow the "BASIC INSPECTION : SPECIAL REPAIR REQUIREMENT ".

  5. CHECK FUEL INJECTORS
    1. Stop engine and then turn ignition switch ON.
    2. Check the voltage between ECM harness connector terminals as follows.
    VOLTAGE SPECIFICATION

    ECM Voltage
    + -
    Connector Terminal Connector Terminal
    F102 81 M107 128 Battery voltage
    82
    85
    86
    89
    90

    Is the inspection result normal? 

    YES: GO TO 6.

    NO: Perform "DIAGNOSIS PROCEDURE ".

  6. CHECK FUNCTION OF IGNITION COIL-I
    CAUTION: Do the following procedure in the place where ventilation is good without the combustible.
    1. Turn ignition switch OFF.
    2. Remove fuel pump fuse (1) in IPDM E/R (2) to release fuel pressure.
      NOTE: Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following procedure.
    3. Start engine.
    4. After engine stalls, crank it two or three times to release all fuel pressure.
    5. Turn ignition switch OFF.
    6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
      Fig 2: Identifying Fuel Pump Fuse And IPDM E/R
      G07165058Courtesy of NISSAN MOTOR CO., U.S.A.
    7. Remove ignition coil and spark plug of the cylinder to be checked.
    8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
    9. Connect spark plug and harness connector to ignition coil.
    10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 - 0.66 in) between the edge of the spark plug and grounded metal portion as shown in the illustration.
    11. Crank engine for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal portion.

    Spark should be generated. 

    Fig 3: Identifying Gap Between Edge Of Spark Plug And Grounded Metal Portion
    G07165059Courtesy of NISSAN MOTOR CO., U.S.A.
    CAUTION:
    • Do not approach to the spark plug and the ignition coil within 50 cm (19.7 in). Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20 kV or more.
    • It might cause to damage the ignition coil if the gap of more than 17 mm (0.66 in) is taken.
    NOTE: When the gap is less than 13 mm (0.52 in), the spark might be generated even if the coil is malfunctioning.

    Is the inspection result normal? 

    YES: GO TO  10.

    NO: GO TO 7.

  7. CHECK FUNCTION OF IGNITION COIL-II
    1. Turn ignition switch OFF.
    2. Disconnect spark plug and connect a known-good spark plug.
    3. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.

    Spark should be generated. 

    Is the inspection result normal? 

    YES: GO TO 8.

    NO: Check ignition coil, power transistor and their circuits. Refer to "DIAGNOSIS PROCEDURE ".

  8. CHECK SPARK PLUG

    Check the initial spark plug for fouling, etc.

    Is the inspection result normal? 

    YES: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "SPARK PLUG ".

    NO: Repair or clean spark plug. Then GO TO 9.

    Fig 4: Identifying Spark Plug Tip
    G07165060Courtesy of NISSAN MOTOR CO., U.S.A.
  9. CHECK FUNCTION OF IGNITION COIL-III
    1. Reconnect the initial spark plugs.
    2. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark plug and the grounded portion.

    Spark should be generated. 

    Is the inspection result normal? 

    YES: INSPECTION END

    NO: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "SPARK PLUG ".

  10. CHECK FUEL INJECTOR
    1. Turn ignition switch OFF.
    2. Remove fuel injector assembly.

      Refer to "REMOVAL AND INSTALLATION ".

      Keep fuel hose and all fuel injectors connected to fuel tube.

    3. Disconnect all ignition coil harness connectors.
    4. Reconnect all fuel injector harness connectors disconnected.
    5. Turn ignition switch ON.

    Does fuel drip from fuel injector? 

    YES: Replace the fuel injector(s) from which fuel is dripping.

    NO: GO TO 11.

  11. CHECK INTERMITTENT INCIDENT

    Refer to "INTERMITTENT INCIDENT "

    Is the inspection result normal? 

    YES: Replace three way catalyst assembly.

    NO: Repair or replace harness or connector.

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