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Home >> Infiniti >> 2005 >> Q45 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - System Testing >> Variable Induction Air Control System (VIAS) >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK OVERALL FUNCTION 

    With CONSULT-II 

    1. Start engine and warm it up to normal operating temperature.
    2. Perform "VIAS SOL VALVE" in "ACTIVE TEST" mode with CONSULT-II.
      Fig 1: Display Active Test Mode
      G02369797Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn VIAS control solenoid valve "ON" and "OFF", and make sure that power valve actuator rod moves.
      Fig 2: Movement Of Power Valve Actuator Rod
      G02369798Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    1. Lift up the vehicle.
    2. Start engine and warm it up to normal operating temperature.
    3. Make sure that power valve actuator rod moves when changing the selector lever position to N and D alternately.
      Fig 3: Checking Power Valve Actuator Rod Movement
      G02369799Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: INSPECTION END 
    2. NG (with CONSULT-II): GO TO 2.
    3. NG (Without CONSULT-II): GO TO  3.
  2. CHECK VACUUM EXISTENCE 

    With CONSULT-II 

    1. Stop engine and disconnect vacuum hose connected to power valve actuator.
    2. Start engine and let it idle.
    3. Perform "VIAS SOL VALVE" in "ACTIVE TEST" mode with CONSULT-II.
    4. Turn VIAS control solenoid valve "ON" and "OFF", and check vacuum existence under the following conditions.
      VACUUM EXISTENCE CONDITIONS

      VIAS SOL VALVE Vacuum
      ON Should exist.
      OFF Should not exist.

    OK or NG 

    1. OK: Repair or replace power valve actuator.
    2. NG: GO TO  4.
    Fig 4: Display Active Test Mode
    G02369800Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK VACUUM EXISTENCE 

    Without CONSULT-II 

    1. Stop engine and disconnect vacuum hose connected to power valve actuator.
    2. Disconnect VIAS control solenoid valve harness connector.
    3. Start engine and let it idle.
    4. Apply 12V of direct current between VIAS control solenoid valve terminals 1 and 2.
    5. Check vacuum existence under the following conditions.
      VACUUM EXISTENCE CONDITIONS

      Condition Vacuum
      12V direct current supply Should exist.
      No supply Should not exist.

    OK or NG 

    1. OK: Repair or replace power valve actuator.
    2. NG: GO TO 4.
    Fig 5: Applying 12V Of Direct Current Between VIAS Control Solenoid Valve Terminals 1 And 2
    G02369801Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK VACUUM HOSE 
    1. Stop engine.
    2. Check hoses and tubes between intake manifold and power valve actuator for crack, clogging, improper connection or disconnection. Refer to "VACUUM HOSE DRAWING ".

    OK or NG 

    1. OK: GO TO 5.
    2. NG: Repair hoses or tubes.
    Fig 6: Checking Vacuum Hose
    G02369802Courtesy of NISSAN MOTOR CO., U.S.A.
  5. CHECK VACUUM TANK 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO 6.
    2. NG: Replace vacuum tank.
  6. CHECK VIAS CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect VIAS control solenoid valve harness connector.
    3. Turn ignition switch ON.
      Fig 7: Locating VIAS Control Solenoid Valve
      G02369803Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between terminal 1 and ground with CONSULT-II or tester.
      1. Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO  8.
    2. NG: GO TO 7.
    Fig 8: Checking Voltage Between Terminal 1 And Ground
    G02369804Courtesy of NISSAN MOTOR CO., U.S.A.
  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M135, F105
    • Harness continuity between VIAS control solenoid valve and ECM relay
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK VIAS CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between ECM terminal 29 and terminal 2.

      Refer to WIRING DIAGRAM .

      1. Continuity should exist. 
    4. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO 9.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  9. CHECK VIAS CONTROL SOLENOID VALVE 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO 10.
    2. NG: Replace VIAS control solenoid valve.
  10. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. INSPECTION END