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Home >> Infiniti >> 2017 >> QX80 Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Introduction, Wiring Diagrams And Basic Inspection) >> Basic Inspection >> Basic Inspection >> Work Procedure >> Diagnostic Test
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Diagnostic Test

  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:
      G04074533Courtesy of NISSAN NORTH AMERICA, INC.
      • 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.
      G04074534Courtesy of NISSAN NORTH AMERICA, INC.

      Check that engine stays below 1, 000 rpm.

    5. Run engine at approximately 2, 000 rpm for approximately 2 minutes under no load.
      G04074535Courtesy of NISSAN NORTH AMERICA, INC.
    6. Check that no DTC is displayed with CONSULT or GST.

    Are any DTCs detected?

    YES 

    GO TO STEP 2  .

    NO 

    GO TO STEP 3  .

  2. REPAIR OR REPLACE

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

    GO TO STEP 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.
      G04074536Courtesy of NISSAN NORTH AMERICA, INC.
    3. Check idle speed.

      For procedure, refer to INSPECTION .

      For specification, refer to IDLE SPEED .

    Is the inspection result normal?

    YES 

    GO TO STEP  10.

    NO 

    GO TO STEP 4  .

  4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING

    1. Stop engine.
    2. Perform DESCRIPTION .

    GO TO STEP 5  .

  5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

    Perform DESCRIPTION .

    GO TO STEP 6  .

  6. PERFORM IDLE AIR VOLUME LEARNING

    Perform DESCRIPTION .

    Is Idle Air Volume Learning carried out successfully?

    YES 

    GO TO STEP 7  .

    NO 

    Follow the instruction of Idle Air Volume Learning. Then GO TO STEP 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 STEP  10.

    NO 

    GO TO STEP 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 STEP 9  .

    NO 

    Repair or replace malfunctioning part. Then GO TO STEP  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 WORK PROCEDURE .

    GO TO STEP  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 STEP  19.

    NO 

    GO TO STEP 11  .

  11. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING

    1. Stop engine.
    2. Perform DESCRIPTION .

    GO TO STEP 12  .

  12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

    Perform DESCRIPTION .

    GO TO STEP 13  .

  13. PERFORM IDLE AIR VOLUME LEARNING

    Perform DESCRIPTION .

    Is Idle Air Volume Learning carried out successfully?

    YES 

    GO TO STEP 14  .

    NO 

    Follow the instruction of Idle Air Volume Learning. Then GO TO STEP  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 STEP 15  .

    NO 

    GO TO STEP  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 STEP  19.

    NO 

    GO TO STEP 16  .

  16. CHECK TIMING CHAIN INSTALLATION

    Check timing chain installation. Refer to REMOVAL AND INSTALLATION .

    Is the inspection result normal?

    YES 

    GO TO STEP 17  .

    NO 

    Repair the timing chain installation. Then GO TO STEP  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 STEP 18  .

    NO 

    Repair or replace malfunctioning part. Then GO TO STEP  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 WORK PROCEDURE .

    GO TO STEP  4.

  19. INSPECTION END

    If ECM is replaced during this BASIC INSPECTION procedure, perform DESCRIPTION .

    INSPECTION END

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