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Home >> Toyota >> 2004 >> Sequoia Limited, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Emission Control System >> Evaporative Emission (EVAP) Control System >> Inspection

Evaporative Emission (EVAP) Control System: Inspection

  1. INSPECT LINES AND CONNECTION 

    Visually check for loose connections, sharp bends or damage.

  2. INSPECT FUEL TANK 

    Visually check for deformation, cracks or fuel leakage.

  3. INSPECT FUEL TANK CAP 

    Visually check if the cap and/or gasket are deformed or damaged.

    If necessary, repair or replace the cap.

    Fig 1: Inspecting Fuel Tank
    G04207919Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INSPECT EVAP SYSTEM LINE 
    1. Warm up the engine and stop the engine.

      Allow the engine to warm up to normal operating temperature.

    2. Install a vacuum gauge (EVAP control system test equipment vacuum gauge) to the EVAP service port on the purge line.
      Fig 2: Installing Vacuum Gauge
      G04207920Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. TOYOTA Hand-Held Tester:

      Forced driving of the VSV for the EVAP.

      1. Connect a TOYOTA hand-held tester to the DLC3.
      2. Start the engine.
      3. Push the TOYOTA hand-held tester main switch ON.
      4. Use the ACTIVE TEST mode on the TOYOTA hand-held tester to operate the VSV for the EVAP.
      Fig 3: Connecting Hand-Held Tester To DLC3
      G04207921Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. If you have no TOYOTA Hand-Held Tester:

      Forced driving of the VSV for the EVAP.

      1. Disconnect the VSV connector for the EVAP.
      2. Connect the positive (+) and negative (-) leads from the battery to the VSV terminals for the EVAP.
      3. Start the engine.
      Fig 4: Connecting Positive (+) And Negative (-) Leads From Battery To VSV Terminals For EVAP
      G04207922Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Check the vacuum at idle.

      Vacuum: Maintain at 0.368 - 19.713 in. Hg (5 - 268 in. Aq) for over 5 seconds 

      HINT:

      If the vacuum does not change, you can conclude that the hose connecting the VSV to the service port has come loose or is blocked, or the VSV is malfunctioning.

    6. TOYOTA Hand-Held Tester:

      Conclude forced driving of the VSV for the EVAP.

      1. Stop the engine.
      2. Disconnect the TOYOTA hand-held tester from the DLC3.
    7. If you have no TOYOTA Hand-Held Tester:

      Conclude forced driving of the VSV for the EVAP.

      1. Stop the engine.
      2. Disconnect the positive (+) and negative (-) leads from the battery from the VSV terminals for the EVAP.
      3. Connect the VSV connector for the EVAP.
    8. Disconnect the vacuum gauge from the EVAP service port on the purge line.
    9. Connect a pressure gauge to the EVAP service port on the purge line.
      Fig 5: Checking Vacuum At Idle
      G04207923Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    10. Check the pressure.
      1. Close off the yellow marked position of the air drain hose with a hose clipper or similar instrument.
        Fig 6: Closing Off Yellow Marked Position Of Air Drain Hose With Hose Clipper
        G04207924Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Add the pressure (13.5 - 15.5 in. Aq) from the EVAP service port.

        Pressure: 2 minutes after the pressure is added, the gauge should be over 7.7 - 8.8 in. Aq. 

        HINT:

        If you can't add pressure, you can conclude that the hose connecting the VSV - canister - fuel tank has slipped off or the VSV is open.

        Fig 7: Checking Pressure
        G04207925Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Check if the pressure decreases when the fuel tank cap is removed while adding pressure.

      HINT:

      If the pressure does not decrease when the filler cap is removed, then you can conclude that the hose connecting the service port to the fuel tank is blocked, etc.

    11. Disconnect the pressure gauge from the EVAP service port on the purge line.
    Fig 8: Removing Fuel Tank Cap
    G04207926Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. CHECK AIRTIGHTNESS IN FUEL TANK AND FILLER PIPE 
    1. Disconnect the EVAP line hose from the charcoal canister side and then pressurize and make the internal pressure in the fuel tank 4 kPa (41 gf/cm2 , 0.58 psi).
    2. Check that the internal pressure of the fuel tank can be hold for 1 minute.
    3. Check the connected portions of each hose and pipe.
    4. Check the installed parts on the fuel tank.

      If there is no abnormality, replace the fuel tank and filler pipe.

    5. Reconnect the EVAP line hose to the charcoal canister.
    Fig 9: Disconnecting EVAP Line Hose
    G04207927Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. INSPECT FUEL CUTOFF VALVE AND FILL CHECK VALVE 
    1. Disconnect the purge line hose and EVAP line hose from the charcoal canister.
    2. Plug the cap to the air drain hose.
    3. Pressurize 4 kPa (41 gf/cm2 , 0.58 psi) to the purge port and check that there is ventilation through the EVAP line hose.
      Fig 10: Disconnecting Purge Line Hose And EVAP Line Hose
      G04207928Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      In the condition that the fuel is full, as the float value of the fill check valve is closed and has no ventilation, it is necessary to check the fuel amount (volume).

    4. Check if there is any struck in the vent line hose and EVAP line hose.

      If there is no stuck in hoses, replace the fuel cutoff valve and f check valve.

    5. Reconnect the purge line hose and EVAP line hose to the charcoal canister.
  7. CHECK AIR INLET LINE 
    1. Disconnect the air inlet line hose from the charcoal canister.
    2. Check that there is ventilation in the air inlet line.
    3. Reconnect the air inlet line hose to the charcoal canister.
  8. REMOVE CHARCOAL CANISTER ASSEMBLY 
    Fig 11: Disconnecting Air Inlet Line Hose
    G04207929Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  9. INSPECT CHARCOAL CANISTER 
    1. Visually check the charcoal canister for cracks or damage.
      Fig 12: Inspecting Charcoal Canister
      G04207930Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Inspect the charcoal canister operation.
      1. While holding the purge port closed, blow air (1.76 kPa, 18 gf/cm2 , 0.26 psi) into the EVAP port and check that air flows from the air drain port.
        Fig 13: Inspecting Charcoal Canister Operation
        G04207931Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. While holding the purge port and the air drain port closed, blow air (1.76 kPa, 18 gf/cm2 , 0.26 psi) into the EVAP port and check that air does not flow from the air inlet port.
        Fig 14: Checking Air Flow
        G04207932Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the purge port, check that the vacuum does not decrease when the air inlet port is closed, and check that the vacuum decreases when the air inlet port is released.
        Fig 15: Applying Vacuum
        G04207933Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. While holding the air inlet port closed, apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in Hg) to the EVAP port and check that air flows into the purge port.

        If operation is not as specified, replace the charcoal canister.

      5. Remove the cap from the vent port.
  10. INSPECT VSV FOR EVAP (See  INSPECTION  ) 
  11. INSPECT VSV FOR CANISTER CLOSED VALVE (CCV) (See  INSPECTION  ) 
  12. INSPECT VSV FOR PRESSURE SWITCHING VALVE (See  INSPECTION  ) 
  13. INSPECT VAPOR PRESSURE SENSOR (See  INSPECTION  ) 
  14. REINSTALL CHARCOAL CANISTER ASSEMBLY 
    Fig 16: Applying Vacuum
    G04207934Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002