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Home >> Toyota >> 2001 >> Sienna CE >> Repair and Diagnosis >> External Pages >> Different car >> Section 97 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0442: Evaporative Emission Control System Leak Detected (Small Leak) & DTC P0456: Evaporative Emission Control System Leak Detected (Very Small Leak) >> Diagnosis & Repair (Using Hand-Held Tester)

Diagnosis & Repair (Using Hand-Held Tester)

WARNING: This page is about a different car, the 2003 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect the hand-held tester to the DLC3. Select the ENHANCED OBD2/SYSTEM CHECK/EVAP SYS CHECK (or EVAP LEAK TEST) mode on the hand-held tester. Perform EVAP SYS CHECK (or EVAP LEAK TEST). If display on the hand-held tester indicates scan tool detects a leak on the fuel tank side, go to step 2) of DTC P0441 OR DTC P0446 . If scan tool detects a leak on the canister side, go to DTC P0441, P0446, step 24. If scan tool detects a leak on the EVAP system, go to next step.
  2. Check that fuel tank cap is LEXUS genuine parts. Replace as necessary. If fuel cap is okay, go to next step.
  3. Check that fuel tank cap is correctly installed. Correctly install fuel tank cap as necessary. If installed correctly, go to next step.
  4. Check fuel tank cap. Replace fuel tank cap as necessary. If cap is okay, go to next step.
  5. Check filler neck for damage. Remove the fuel tank cap. Visually inspect the filler neck for damage. Repair as necessary. If filler pipe is okay, go to next step.
  6. Connect hand-held tester to the DLC3. Select the ENHANCED OBD2/ACTIVE TEST mode on the hand-held tester. Disconnect the vacuum hose for the VSV for the EVAP from the charcoal canister. Start the engine. Select the item EVAP (ALON)/ALL in the ACTIVE TEST and operate VSV for EVAP. When the VSV for the EVAP is operated by the hand-held tester, check whether the disconnected hose applies suction to your finger. If VSV is ON, disconnected hose applies suction to your finger. If VSV is OFF, disconnected hose applies no suction to your finger. See Figure. If okay, go to step  10. If not okay, go to next step.
  7. Check vacuum hose between intake manifold and VSV for EVAP, and VSV for EVAP and charcoal canister. Check if vacuum hose is connected correctly. Check the vacuum hose for looseness and disconnection. Check the vacuum hose for cracks, holes, damage and blockages. Repair as necessary. If okay, go to next step.
  8. Check operation of VSV for EVAP. See FUEL EVAPORATION SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. Replace as necessary. If okay, go to next step.
  9. Check for open and short in harness and connector between EFI relay and VSV for EVAP, and VSV for EVAP and ECM. Repair or replace harness or connector. If okay, check and replace ECM.
  10. Disconnect the vacuum hose for the VSV for the CCV from the charcoal canister. Turn the ignition switch ON and push the hand-held tester main switch ON. Select the ENHANCED OBD2/ACTIVE TEST mode on the hand-held tester. Select the item INTAKE CTL VSV/ALL in the ACTIVE TEST and operate VSV for EVAP. Check the VSV operation when it is operated by the hand-held tester. When VSV is ON, air does not flow from port "E" to port "F". When VSV is OFF, air from port "E" flows out through port "F". See Figure. If okay, go to step  14. If not okay, go to next step.
  11. Check vacuum hose between VSV for CCV and charcoal canister. Check if the vacuum hose is connected correctly. Check the vacuum hose for looseness and disconnection. Check the vacuum hose for cracks, damage and blockages. Repair or replace as necessary. If okay, go to next step.
  12. Check operation of VSV for CCV. See FUEL EVAPORATION SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. Replace VSV for CCV as necessary. If okay, go to next step.
  13. Check for open and short in harness and connector between EFI relay and VSV for CCV, and VSV for CCV and ECM. Repair or replace harness or connector. If okay, replace ECM.
  14. Connect the hand-held tester to the DLC3. Turn the ignition switch ON and push the hand-held tester main switch ON. Select the ACTIVE TEST mode on the hand-held tester. Check the VSV operation when it is operated by the hand-held tester. If VSV is ON, air from port "E" flows out through port "F". If VSV is OFF, air does not flow from port "E" to port "F". See Fig 1. If okay, go to step  17. If not okay, go to next step.
    Fig 1: Checking VSV For Pressure Switching Valve
    G00165085Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  15. Check operation of VSV for pressure switching valve. See FUEL EVAPORATION SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. Replace as necessary. If okay, go to next step.
  16. Check for open and short in harness and connector between EFI relay and VSV for pressure switching valve, and VSV for pressure switching valve and ECM. Repair or replace harness or connector as necessary. If okay, check and replace ECM.
  17. Check for cracks, deformation and loose connection of fuel tank, charcoal canister, fuel tank filler pipe, and hoses and tubes around fuel tank and charcoal canister. See Figure. Repair or replace as necessary. If okay, go to next step.
  18. Check vacuum hoses between vapor pressure sensor and fuel tank, and charcoal canister and VSV for pressure switching valve. Check that the vacuum hose is connected correctly. Check the vacuum hose for looseness and disconnection. Check the vacuum hose for cracks, holes and damages. Repair as necessary. If okay, go to next step.
  19. Check vacuum hoses. Check that the vacuum hose is connected correctly. Check the vacuum hose for looseness and disconnection. Check the vacuum hose for cracks, hole and damage. Repair or replace as necessary. If okay, go to next step.
  20. Check hose and tube between fuel tank and charcoal canister. Check for proper connection of the fuel tank and fuel evaporation pipe, fuel evaporation pipe and fuel tube under the floor, fuel tube under the floor and charcoal canister. Check the hose and tube for cracks, holes and damages. Repair or replace as necessary. If okay, go to next step.
  21. Check charcoal canister for cracks, hole and damage. Repair or replace as necessary. If okay, go to next step.
  22. Remove the glove compartment. Turn the ignition switch ON. Measure the voltage between terminals VC and E2 of the ECM connector. See Figure. If voltage is 4.5-5.5 volts, go to next step. If voltage is not to specification, check and replace ECM.
  23. Remove the glove compartment. Turn the ignition switch ON. Measure the voltage between terminals PTNK and E2 of the ECM connectors. Disconnect the vacuum hose from the vapor pressure sensor. Using the MITYVAC (Hand-Held Vacuum Pump), apply a vacuum of 1.18 in. Hg (4.0 kPa, 30 mm Hg) to the vapor pressure sensor. Vacuum applied to the vapor pressure sensor must be less than 19.7 in. Hg (66.7 kPa, 500 mm Hg). See Figure. If voltage is 2.9-3.7 volts, or 0.5 volts or less, go to step  25. If voltage is not to specification, go to next step.
  24. Check for open and short in harness and connector between vapor pressure sensor and ECM. Repair or replace harness or connector. If okay, replace vapor pressure sensor.
  25. Check fuel tank and fuel tank over fill check valve for cracks and damage. Replace fuel tank or fuel tank over fill check valve as necessary. If okay, it is likely that vehicle user did not properly close fuel tank cap. Explain to customer how to properly install fuel tank cap.
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