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Home >> Toyota >> 2001 >> RAV4 Base, AWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing - 4-Cylinder >> Emission Systems & Sub-Systems >> Fuel Evaporative System >> Fuel EVAP System Test (ECHO)
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Fuel EVAP System Test (ECHO)

NOTE: Manufacturer provides testing information for testing airtightness of fuel tank and components along with testing of charcoal canister and fuel EVAP system.
  1. Inspect all fuel EVAP system lines and connections for sharp bends or damage. Fuel inlet pipe may also be referred to as fuel filler pipe. Inspect fuel inlet pipe for cracks, damage or fuel leakage. Inspect fuel tank cap for cracks or deformed gasket. Replace components if defective or damaged.
  2. Start engine and warm engine to normal operating temperature. Shut engine off. Connect vacuum gauge from EVAP System Test Kit (00002-6872A-01) to EVAP service port. EVAP service port is located in engine compartment, in purge vacuum hose for EVAP system. See Figure.
  3. Operate EVAP Vacuum Switching Valve (VSV). If Toyota hand-held tester is available to operate EVAP VSV, go to next step. If Toyota hand-held tester is not available to operate EVAP VSV, go to step  5.
  4. Connect hand-held tester to data link connector No. 3. See Figure. Start engine. Turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate EVAP VSV. Go to step  6.
  5. Disconnect electrical connector at EVAP VSV. EVAP VSV is located on bracket at inside of air cleaner housing and contains Blue 2-pin electrical connector with Black/Yellow and White/Green wires. See Figure. Using jumper wires, connect battery voltage and ground to electrical terminals on EVAP VSV to operate EVAP VSV. Start engine. Go to next step.
  6. Check vacuum reading on vacuum gauge with engine idling. Vacuum reading should be.368-19.713 in. Hg (5.00-268.00 in. H2O) for over 5 seconds. If vacuum reading is within specification, go to next step. If vacuum reading is not within specification, check for loose or restricted vacuum hose to EVAP service port, or for malfunctioning EVAP VSV. To check EVAP VSV operation, see EVAP VACUUM SWITCHING VALVE .
  7. Shut engine off. If using hand-held tester to operate EVAP VSV, stop operation of EVAP VSV. Leave hand-held tester connected to data link connector No. 3 and go to next step. If connecting battery voltage to EVAP VSV to operate EVAP VSV, disconnect jumper wires and reconnect electrical connector on EVAP VSV. Go to next step.
  8. Disconnect vacuum gauge from EVAP service port. Connect pressure gauge to EVAP service port. Operate Canister Closed Valve Vacuum Switching Valve (CCV VSV). If Toyota hand-held tester is available to operate CCV VSV, go to next step. If Toyota hand-held tester is not available to operate CCV VSV, go to step  10.
  9. With hand-held tester still connected to DLC No. 3, turn ignition on and then turn hand-held tester on. DO NOT start engine. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate CCV VSV. Go to step  11.
  10. Install hose crimper on air drain hose near charcoal canister. Charcoal canister is located near fuel tank. See Figure. Perform STEP 1 in illustration. See Fig 1. Go to next step.
    11. NOTE: If using hand-held tester to activate CCV VSV, this step must be completed within 10 minutes after CCV VSV was activated or CCV VSV will be reset.
  11. Apply 13.5-15.5 in. H2O of pressure to EVAP service port. After 2 minutes of applying pressure, pressure should be 7.7-8.8 in. H2O. If pressure is within specification, go to next step. If pressure cannot be maintained, check for disconnected vacuum hose between EVAP VSV, charcoal canister and fuel tank. If vacuum hose is properly installed on EVAP VSV, charcoal canister and fuel tank, check for stuck open EVAP VSV. To check EVAP VSV operation, see EVAP VACUUM SWITCHING VALVE .
  12. With pressure still applied at EVAP service port, remove fuel tank cap and note pressure reading. Pressure should decrease when fuel tank cap is removed. If pressure decreases when fuel tank cap is removed and hand-held tester was used to activate CCV VSV, turn ignition off. Remove pressure gauge and hand-held tester. Go to next step. If pressure decreases when fuel tank cap is removed and hand-held tester was not used to operate CCV VSV, remove hose crimper and pressure gauge. Go to next step. If pressure does not decrease when fuel tank cap is removed, remove pressure gauge and hose crimper. Check for restricted vacuum hose between EVAP service port, charcoal canister and fuel tank. Repair or replace vacuum hose as necessary.
  13. To check airtightness of fuel tank and fuel inlet pipe, disconnect EVAP line hose from charcoal canister by pinching both sides of connector together. Perform STEP 2 in illustration. See Fig 1. Apply.58 psi (.040 kg/cm2 ) air pressure to EVAP line hose so pressure inside fuel tank is.58 psi (.040 kg/cm2 ). Check that pressure inside fuel tank holds steady for one minute.
  14. If pressure inside fuel tank holds steady for one minute, reinstall EVAP line hose on charcoal canister. Go to next step. If pressure inside fuel will not hold steady for one minute, check for leaking hoses or pipes at fuel tank and fuel inlet pipe, or for leaks at fuel tank or installed components on fuel tank. If no leaks exist, replace fuel tank and fuel inlet pipe. Reinstall EVAP line hose on charcoal canister. Go to next step.
    15. NOTE: Overfill check valve may also be referred to as fill check valve. Cut-off valve may also be referred to as fuel cut-off valve.
  15. To check overfill check valve and cut-off valve, disconnect purge line hose and EVAP line hose from charcoal canister, and install cap on air drain hose. Perform STEP 3 in illustration. See Fig 1.
  16. Apply.58 psi (.040 kg/cm2 ) air pressure to purge line hose fitting on charcoal canister. Perform STEP 3 in illustration. See Fig 1. Ensure air flows from EVAP line hose when air pressure is applied to purge line hose fitting on charcoal canister. If fuel tank is full of fuel, air may not flow from EVAP line hose, as overfill check valve may be closed. Ensure fuel tank is not full of fuel when checking for airflow at EVAP line hose.
  17. If air flows from EVAP line hose, go to next step. If air does not flow from EVAP line hose, check for restrictions in EVAP line hose and vent line hose. If any hose is restricted, replace hose and recheck operation. If hoses are not restricted, replace overfill check valve and cut-off valve located on top of fuel tank. See Figure.
  18. Reinstall purge line hose and EVAP line hose on charcoal canister. To check air inlet line, disconnect air inlet line hose from charcoal canister. Perform STEP 4 in illustration. See Fig 1. Apply air pressure to air inlet line hose. Air should flow through air inlet line hose. If air flows through air inlet line hose, go to next step. If air does not flow through air inlet line hose, check for restricted air inlet line hose or air inlet line.
  19. To check charcoal canister, disconnect necessary electrical connectors and components for removal of charcoal canister. Disconnect purge line hose, EVAP line hose and air inlet line hose from charcoal canister if not previously done.
  20. Push connector on vent line hose toward charcoal canister, pinch both sides of retainer on connector, and disconnect vent line hose with connector from charcoal canister. See Fig 2.
  21. Remove charcoal canister nuts. Remove charcoal canister. Inspect charcoal canister for cracks or damage. If charcoal canister is okay, go to next step. If charcoal canister is defective, replace charcoal canister.
  22. Install cap on vent port on charcoal canister. See Fig 3. Apply.26 psi (.018 kg/cm2 ) air pressure to EVAP port while holding purge port closed. See Fig 3. Ensure air flows freely from air drain port.
  23. Apply.26 psi (.018 kg/cm2 ) air pressure to EVAP port while holding air drain port and purge port closed. See Fig 3. Ensure air does not flow from air inlet port.
  24. Using vacuum pump, apply 1.01 in. Hg of vacuum to purge port. See Fig 3. Ensure vacuum does not decrease when air inlet port is closed and that vacuum decreases when air inlet port is opened.
  25. While holding air inlet port closed, use vacuum pump to apply 1.01 in. Hg of vacuum to EVAP port. See Figure. Ensure air flows into purge port. Remove cap from vent port. Replace charcoal canister if defective.
  26. Reinstall charcoal canister. If fuel EVAP system operates properly, it may be necessary to check operation of EVAP Vacuum Switching Valve (VSV), canister closed valve Vacuum Switching Valve (VSV) and vapor pressure sensor. See EVAP VACUUM SWITCHING VALVE , CANISTER CLOSED VALVE VACUUM SWITCHING VALVE  and VAPOR PRESSURE SENSOR .
    Fig 1: Testing Fuel EVAP System & Lines (ECHO)
    G99I54781Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Disconnecting Vent Line Hose & Connector At Charcoal Canister (ECHO)
    G99J54782Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 3: Identifying Charcoal Canister Ports (ECHO)
    G99A54783Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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