Emission Control System: Inspection

INSPECT CHARCOAL CANISTER ASSY
1. Visually check the charcoal canister for cracks or damage.
  
  Fig 1: Visually Checking Charcoal Canister For Cracks Or Damage
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Inspect the charcoal canister operation.
  1. Plug the vent port with the cap.
  2. While holding the purge port closed, blow air (1.76 kPa, 18 gf/cm² , 0.26 psi) into the EVAP port to check that air flows from the air drain port. See Fig 2.
    
    Fig 2: Inspecting Charcoal Canister Operation - Air Flow From The Air Drain Port
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. 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 to check that air does not flow from the air inlet port. See Fig 3.
    
    Fig 3: Inspecting Charcoal Canister Operation - Air Inlet Port
    Courtesy 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 purge port to check that the vacuum does not decrease. And then, release the air inlet port to check that the vacuum decreases. See Fig 4.
    
    Fig 4: Inspecting Charcoal Canister Operation - Purge Port
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. While holding the air inlet port closed, apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the EVAP port to check that air flows into the purge port. See Fig 5.
    If the operation is not as specified, replace the charcoal canister.
  6. Remove the hose and cap from the vent port.
    
    Fig 5: Inspecting Charcoal Canister Operation - Air Flow From Purge Port
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Inspect the VSV for the pressure switching valve assy.
  1. Using an ohmmeter, check the resistance between the terminals.
    Resistance: 37 - 44 +/- at 20°C (68°F)
    
    If the resistance is not as specified, replace the VSV.
    
    Fig 6: Inspecting VSV For Pressure Switching Valve Assy. Resistance
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Using an ohmmeter, check that there is no continuity between each terminal and the body ground.
    If there is continuity, replace the VSV.
    
    Fig 7: Checking That There Is No Continuity Between Each Terminal Of VSV For Pressure Switching Valve & Body Ground
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Check that air does not flow from port E to port F.
    
    Fig 8: Checking That Air Does Not Flow From Port E To Port F Of VSV For Pressure Switching Valve
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Apply battery positive voltage across the terminals.
  5. Check that air flows from port E to port F.
    If the operation is not as specified, replace the VSV.
    
    Fig 9: Applying Battery Positive Voltage Across VSV Terminals
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Inspect the VSV for the pressure switching valve assy.
  1. Using an ohmmeter, check the resistance between the terminals.
    Resistance: 37 - 44 +/- at 20°C (68°F)
    
    If the resistance is not as specified, replace the VSV.
    
    Fig 10: Checking Resistance Between VSV Terminals
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Using an ohmmeter, check that there is no continuity between each terminal and the body ground.
    If there is no continuity, replace the VSV.
    
    Fig 11: Checking That There Is No Continuity Between Each VSV Terminal & Body Ground
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Check that air does not flow from port E to port F.
    
    Fig 12: Checking Air Does Not Flow From Port E To Port F Of VSV
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Apply battery positive voltage across the terminals.
  5. Check that air flows from port E to port F.
    If the operation is not as specified, replace the VSV.
    
    Fig 13: Applying Battery Positive Voltage Across VSV Terminals To Check Air Flow Across Ports E And F
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
VENTILATION VALVE SUB-ASSY
1. Install a clean hose to the PCV valve.
2. Inspect the PCV valve operation.
  1. Blow air from the cylinder head side of the engine, and check that air passes through easily.
    CAUTION: Do not suck air through the valve. Petroleum substances stuck to the valve is harmful.
    
    Fig 14: Blowing Air From Cylinder Head Side Of Engine To Check PCV Valve Flow
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Blow air from the intake manifold side of the engine, and check that air passes through with difficulty.
    If the operation is not as specified, replace the PCV valve.
3. Remove the clean hose from the PCV valve.
  
  Fig 15: Blowing Air From Intake Manifold Side Of Engine & Checking That Air Passes Through PCV Valve With Difficulty
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
FUEL TANK CAP ASSY
1. Visually check if cap and/or gasket are deformed or damaged.
  If necessary, repair or replace the cap.
  
  Fig 16: Identifying Fuel Tank Cap Gasket
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT VACUUM SWITCHING VALVE ASSY
1. Inspect the VSV for the evaporative emission (EVAP).
  1. Using an ohmmeter, check the resistance between the terminals.
    Resistance: 27 - 33 +/- at 20°C (68°F)
    
    If the resistance is not as specified, replace the VSV.
    
    Fig 17: Checking Resistance Between VSV Terminals
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Using an ohmmeter, check that there is no continuity between each terminal and the body ground.
    If there is continuity, replace the VSV.
    
    Fig 18: Checking That There Is No Continuity Between Each EVAP VSV Terminal & Body Ground
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Check that air flows from port E to port F.
    
    Fig 19: Checking That Air Flows From Port E To Port F Of EVAP VSV
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Apply battery positive voltage across the terminals.
  5. Check that air does not flow from port E to port F.
    If the operation is not as specified, replace the VSV.
    
    Fig 20: Applying Battery Positive Voltage Across EVAP VSV Terminals To Check Air Flow From Port E To F
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
VACUUM SWITCHING VALVE ASSY NO.1
1. Inspect the VSV for the canister closed valve (CCV).
  1. Using an ohmmeter, check the resistance between the terminals.
    Resistance: 25 - 30 +/- at 20°C (68°F)
    
    If the resistance is not as specified, replace the VSV.
    
    Fig 21: Checking Resistance Between Canister Closed Valve VSV Terminals
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Using an ohmmeter, check that there is no continuity between each terminal and the body ground.
    If there is continuity, replace the VSV.
    
    Fig 22: Checking That There Is No Continuity Between Each Canister Closed Valve VSV Terminal & Body Ground
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Check that air flows from port A to port B.
    
    Fig 23: Checking That Air Flows From Port A To Port B Of Canister Closed Valve VSV
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Apply battery positive voltage across the terminals.
  5. Check that air does not flow from port A to port B.
    If the operation is not as specified, replace the VSV.
    
    Fig 24: Applying Battery Positive Voltage Across Terminals Of Canister Closed Valve VSV
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002