LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2012 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System - Introduction (For MEXICO) >> Basic Inspection >> Basic Inspection >> Work Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Work Procedure

  1. INSPECTION START
    1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for scheduled maintenance.
    2. Open engine hood and check the following:
      • Harness connectors for improper connections
      • Wiring harness for improper connections, pinches and cut
      • Vacuum hoses for splits, kinks and improper connections
      • Hoses and ducts for leakage
      • Air cleaner clogging
      • Gasket
    3. Check that electrical or mechanical loads are not applied.
      • Headlamp switch is OFF.
      • Air conditioner switch is OFF.
      • Rear window defogger switch is OFF.
      • Steering wheel is in the straight-ahead position, etc.
    4. Start engine and warm it up until engine coolant temperature indicator points to the middle of gauge.

      Check that engine stays below 1, 000 rpm.

      Fig 1: Checking Harness Connectors For Improper Connections
      G08257071Courtesy of NISSAN NORTH AMERICA, INC.
      Fig 2: Identifying Engine Coolant Temperature
      G08257072Courtesy of NISSAN NORTH AMERICA, INC.
    5. Run engine at approximately 2, 000 rpm for approximately 2 minutes under no load.
    6. Check that no DTC is displayed with CONSULT or GST.
      Fig 3: Identifying Engine RPM
      G08257073Courtesy of NISSAN NORTH AMERICA, INC.

      Are any DTCs detected? 

      YES: GO TO 2.

      NO: GO TO  3.

  2. REPAIR OR REPLACE

    Repair or replace components as necessary according to corresponding Diagnosis Procedure.

    : GO TO 3

  3. CHECK IDLE SPEED
    1. Run engine at approximately 2, 000 rpm for approximately 2 minutes under no load.
    2. Rev engine between 2, 000 and 3, 000 rpm 2 or 3 times under no load, then run engine at idle speed for approximately 1 minute.
    3. Check idle speed.

      For procedure, refer to "INSPECTION ".

      For specification, refer to "IDLE SPEED ".

      Fig 4: Checking Target Idle Speed
      G08257074Courtesy of NISSAN NORTH AMERICA, INC.

      Is the inspection result normal? 

      YES: GO TO  10.

      NO: GO TO 4.

  4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
    1. Stop engine.
    2. Perform "WORK PROCEDURE ".

      : GO TO 5.

  5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

    Perform "WORK PROCEDURE ".

    : GO TO 6.

  6. PERFORM IDLE AIR VOLUME LEARNING

    Perform "WORK PROCEDURE ".

    Is Idle Air Volume Learning carried out successfully? 

    YES: GO TO 7.

    NO: Follow the instruction of Idle Air Volume Learning. Then GO TO  4.

  7. CHECK IDLE SPEED AGAIN
    1. Start engine and warm it up to normal operating temperature.
    2. Check idle speed.

      For procedure, refer to "INSPECTION ".

      For specification, refer to "IDLE SPEED ".

      Is the inspection result normal? 

      YES: GO TO  10.

      NO: GO TO 8.

  8. DETECT MALFUNCTIONING PART

    Check the Following.

    • Check camshaft position sensor and circuit. Refer to "DTC LOGIC ".
    • Check crankshaft position sensor and circuit. Refer to "DTC LOGIC ".

      Is the inspection result normal? 

      YES: GO TO 9.

      NO: Repair or replace malfunctioning part. Then GO TO  4.

  9. CHECK ECM FUNCTION
    1. Substitute with a non-malfunctioning ECM to check ECM function. (ECM may be the cause of the incident, although this is rare.)
    2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to "ECM: WORK PROCEDURE ".

      : GO TO  4.

  10. CHECK IGNITION TIMING
    1. Run engine at idle.
    2. Check ignition timing with a timing light.

      For procedure, refer to "INSPECTION ".

      For specification, refer to "IGNITION TIMING ".

      Is the inspection result normal? 

      YES: GO TO  19.

      NO: GO TO 11.

  11. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
    1. Stop engine.
    2. Perform "WORK PROCEDURE ".

      : GO TO 12.

  12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

    Perform "WORK PROCEDURE ".

    : GO TO 13.

  13. PERFORM IDLE AIR VOLUME LEARNING

    Perform "WORK PROCEDURE ".

    Is Idle Air Volume Learning carried out successfully? 

    YES: GO TO 14.

    NO: Follow the instruction of Idle Air Volume Learning. Then GO TO  4.

  14. CHECK IDLE SPEED AGAIN
    1. Start engine and warm it up to normal operating temperature.
    2. Check idle speed.

      For procedure, refer to "INSPECTION ".

      For specification, refer to "IDLE SPEED ".

      Is the inspection result normal? 

      YES: GO TO 15.

      NO: GO TO  17.

  15. CHECK IGNITION TIMING AGAIN
    1. Run engine at idle.
    2. Check ignition timing with a timing light.

      For procedure, refer to "INSPECTION ".

      For specification, refer to "IGNITION TIMING ".

      Is the inspection result normal? 

      YES: GO TO  19.

      NO: GO TO 16.

  16. CHECK TIMING CHAIN INSTALLATION

    Check timing chain installation. Refer to "REMOVAL AND INSTALLATION ".

    Is the inspection result normal? 

    YES: GO TO 17.

    NO: Repair the timing chain installation. Then GO TO  4.

  17. DETECT MALFUNCTIONING PART

    Check the following.

    • Check camshaft position sensor and circuit. Refer to "DTC LOGIC ".
    • Check crankshaft position sensor and circuit. Refer to "DTC LOGIC ".

      Is the inspection result normal? 

      YES: GO TO 18.

      NO: Repair or replace malfunctioning part. Then GO TO  4.

  18. CHECK ECM FUNCTION
    1. Substitute with a non-malfunctioning ECM to check ECM function. (ECM may be the cause of the incident, although this is rare.)
    2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to "ECM: WORK PROCEDURE ".

      : GO TO  4.

  19. INSPECTION END

    If ECM is replaced during this BASIC INSPECTION procedure, perform "WORK PROCEDURE ".

    : INSPECTION END