LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2008 >> EX35 Base, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - Introduction >> Component Diagnosis >> Trouble Diagnosis - Specification Value >> Diagnosis Procedure >> Detailed Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Detailed Procedure

  1. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2"

    With CONSULT-III 

    1. Start engine.
    2. Confirm that the testing conditions are met. Refer to "COMPONENT FUNCTION CHECK ".
    3. Select "A/F ALPHA-B1", "A/F ALPHA-B2" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.
      NOTE: Check "A/F ALPHA-B1", "A/F ALPHA-B2" for approximately 1 minute because they may fluctuate. It is NG if the indication is out of the SP value even a little.

    Is the measurement value within the SP value? 

    YES: GO TO  17.

    NO-1: Less than the SP value: GO TO 2.

    NO-2: More than the SP value: GO TO  3.

  2. CHECK "B/FUEL SCHDL"

    Select "B/FUEL SCHDL" in "SPEC" of "DATA MONITOR" mode, and check that the indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: GO TO  4.

    NO: More than the SP value: GO TO  19.

  3. CHECK "B/FUEL SCHDL"

    Select "B/FUEL SCHDL" in "SPEC" of "DATA MONITOR" mode, and check that the indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: GO TO  6.

    NO-1: More than the SP value: GO TO  6.

    NO-2: Less than the SP value: GO TO  25.

  4. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2"
    1. Stop the engine.
    2. Disconnect PCV hose, and then plug it.
    3. Start engine.
    4. Select "A/F ALPHA-B1", "A/F ALPHA-B2" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: GO TO 5.

    NO: GO TO  6.

  5. CHANGE ENGINE OIL
    1. Stop the engine.
    2. Change engine oil.
      NOTE: This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving conditions (such as when engine oil temperature does not rise enough since a journey distance is too short during winter). The symptom will not be detected after changing engine oil or changing driving condition.

      INSPECTION END

  6. CHECK FUEL PRESSURE

    Check fuel pressure. (Refer to "INSPECTION ".)

    Is the inspection result normal? 

    YES: GO TO  9.

    NO-1: Fuel pressure is too high: Replace "fuel filter and fuel pump assembly" and then GO TO  8.

    NO-2: Fuel pressure is too low: GO TO 7.

  7. DETECT MALFUNCTIONING PART

    Check fuel hoses and fuel tubes for clogging.

    Is the inspection result normal? 

    YES: Replace "fuel filter and fuel pump assembly" and then GO TO 8.

    NO: Repair or replace and then GO TO 8.

  8. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2"
    1. Start engine.
    2. Select "A/F ALPHA-B1", "A/F ALPHA-B2" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: GO TO 9.

  9. PERFORM POWER BALANCE TEST
    1. Perform "POWER BALANCE" in "ACTIVE TEST" mode.
    2. Make sure that the each cylinder produces a momentary engine speed drop.

    Is the inspection result normal? 

    YES: GO TO  12.

    NO: GO TO 10.

  10. DETECT MALFUNCTIONING PART

    Check the following.

    Is the inspection result normal? 

    YES: Replace fuel injector and then GO TO 11.

    NO: Repair or replace malfunctioning part and then GO TO 11.

  11. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2"
    1. Start engine.
    2. Select "A/F ALPHA-B1", "A/F ALPHA-B2" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: GO TO 12.

  12. CHECK A/F SENSOR 1 FUNCTION

    Perform all DTC CONFIRMATION PROCEDURE related with A/F sensor 1.

    • For DTC P0130, P0150, refer to "DTC LOGIC ".
    • For DTC P0131, P0151, refer to "DTC LOGIC ".
    • For DTC P0132, P0152, refer to "DTC LOGIC ".
    • For DTC P0133, P0153, refer to "DTC LOGIC ".
    • For DTC P2A00, P2A03, refer to "DTC LOGIC ".

    Is any DTC detected? 

    YES: GO TO 13.

    NO: GO TO  15.

  13. CHECK A/F SENSOR 1 CIRCUIT

    Perform Diagnosis Procedure according to corresponding DTC.

    GO TO 14.

  14. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2"
    1. Start engine.
    2. Select "A/F ALPHA-B1", "A/F ALPHA-B2" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: GO TO 15.

  15. DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
    1. Stop the engine.
    2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.

      GO TO 16.

  16. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2"
    1. Start engine.
    2. Select "A/F ALPHA-B1", "A/F ALPHA-B2" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: Detect malfunctioning part according to "SYMPTOM TABLE ".

  17. CHECK "B/FUEL SCHDL"

    Select "B/FUEL SCHDL" in "SPEC" of "DATA MONITOR" mode, and check that the indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO-1: More than the SP value: GO TO 18.

    NO-2: Less than the SP value: GO TO  25.

  18. DETECT MALFUNCTIONING PART
    1. Check for the cause of large engine friction. Refer to the following.
      • Engine oil level is too high
      • Engine oil viscosity
      • Belt tension of power steering, alternator, A/C compressor, etc. is excessive
      • Noise from engine
      • Noise from transmission, etc.
    2. Check for the cause of insufficient combustion. Refer to the following.
      • Valve clearance malfunction
      • Intake valve timing control function malfunction
      • Camshaft sprocket installation malfunction, etc.

        Repair or replace malfunctioning part, and then GO TO  30.

  19. CHECK INTAKE SYSTEM

    Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.

    • Crushed air ducts
    • Malfunctioning seal of air cleaner element
    • Uneven dirt of air cleaner element
    • Improper specification of intake air system

    Is the inspection result normal? 

    YES: GO TO  21.

    NO: Repair or replace malfunctioning part, and then GO TO 20.

  20. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2", AND "B/FUEL SCHDL"

    Select "A/F ALPHA-B1", "A/F ALPHA-B2", and "B/FUEL SCHDL" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: "B/FUEL SCHDL" is more, "A/F ALPHA-B1", "A/F ALPHA-B2" are less than the SP value: GO TO 21.

  21. DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
    1. Stop the engine.
    2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and then reconnect it again.

      GO TO 22.

  22. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2"
    1. Start engine.
    2. Select "A/F ALPHA-B1", "A/F ALPHA-B2" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to "DIAGNOSIS PROCEDURE ". Then GO TO  29.

    NO: GO TO 23.

  23. CHECK "MAS A/F SE-B1", "MAS A/F SE-B2"

    Select "MAS A/F SE-B1", "MAS A/F SE-B2" in "SPEC" of "DATA MONITOR" mode, and check that the indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: GO TO 24.

    NO: More than the SP value: Replace malfunctioning mass air flow sensor, and then GO TO  29.

  24. REPLACE ECM
    1. Replace ECM.
    2. Go to "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : SPECIAL REPAIR REQUIREMENT ".

      GO TO  29.

  25. CHECK INTAKE SYSTEM

    Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.

    • Crushed air ducts
    • Malfunctioning seal of air cleaner element
    • Uneven dirt of air cleaner element
    • Improper specification of intake air system

    Is the inspection result normal? 

    YES: GO TO  27.

    NO: Repair or replace malfunctioning part, and then GO TO 26.

  26. CHECK "B/FUEL SCHDL"

    Select "B/FUEL SCHDL" in "SPEC" of "DATA MONITOR" mode, and check that the indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: Less than the SP value: GO TO 27.

  27. CHECK "MAS A/F SE-B1", "MAS A/F SE-B2"

    Select "MAS A/F SE-B1", "MAS A/F SE-B2" in "SPEC" of "DATA MONITOR" mode, and check that the indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: GO TO 28.

    NO: Less than the SP value: Replace malfunctioning mass air flow sensor, and then GO TO  30.

  28. CHECK INTAKE SYSTEM

    Check for the cause of air leak after the mass air flow sensor. Refer to the following.

    • Disconnection, looseness, and cracks in air duct
    • Looseness of oil filler cap
    • Disconnection of oil level gauge
    • Open stuck, breakage, hose disconnection, or cracks of PCV valve
    • Disconnection or cracks of EVAP purge hose, open stuck of EVAP canister purge volume control solenoid valve
    • Malfunctioning seal of rocker cover gasket
    • Disconnection, looseness, or cracks of hoses, such as vacuum hose, connecting to intake air system parts
    • Malfunctioning seal of intake air system, etc.

      GO TO  30.

  29. CHECK "A/F ALPHA-B1", "A/F ALPHA-B2", AND "B/FUEL SCHDL"

    Select "A/F ALPHA-B1", "A/F ALPHA-B2", and "B/FUEL SCHDL" in "SPEC" of "DATA MONITOR" mode, and check that the each indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: Detect malfunctioning part according to "SYMPTOM TABLE ".

  30. CHECK "B/FUEL SCHDL"

    Select "B/FUEL SCHDL" in "SPEC" of "DATA MONITOR" mode, and then check that the indication is within the SP value.

    Is the measurement value within the SP value? 

    YES: INSPECTION END

    NO: Detect malfunctioning part according to "SYMPTOM TABLE ".

scientia non olet · About LEMON Manuals