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Home >> Toyota >> 2001 >> Sienna CE >> Repair and Diagnosis >> External Pages >> Different car >> Section 99 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0442: Evaporative Emission Control System Leak Detected (Small Leak) Or 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 LX 470. 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 hand-held tester. Perform EVAP SYS CHECK (or EVAP LEAK TEST). If scan tool detects a leak on the fuel tank side or canister side, go to DTC P0441 OR DTC P0446 . If scan tool detects a leak on EVAP system, go to next step.
  2. Check that fuel tank cap is genuine Lexus parts. Replace as necessary. If okay, go to next step.
  3. Check that fuel tank cap is correctly installed. Replace as necessary. If okay, go to next step.
  4. Check fuel tank cap. Replace as necessary. If okay, go to next step.
  5. Check filler neck for damage. Replace as necessary. If okay, go to next step.
  6. Connect the 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. With VSV ON, disconnected hose applies suction to your finger. With VSV 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 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 as necessary. If okay, go to next step.
  8. Check operation of VSV for EVAP. See FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEMS & COMPONENT TESTING - LX470 article. Replace as necessary. If okay, go to next step.
  9. Check for open and short in harness and connector between EFI or ECD relay and VSV for EVAP, and VSV for EVAP and ECM. Repair or replace as necessary. If okay, 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 ENHANCED OBD2/ACTIVE TEST mode on hand-held tester. Select INTAKE CTL VSV/ALL in 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. Repair as necessary. If okay, go to next step.
  12. Check operation of VSV for CCV. See FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEMS & COMPONENT TESTING - LX470 article. If okay, go to next step. If not okay, replace as necessary.
  13. Check for open and short in harness and connector between EFI or ECD relay and VSV for CCV, and VSV for CCV and ECM. Repair as necessary. If okay, check and 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 ENHANCED OBD2/ACTIVE TEST mode on the hand-held tester. Select TANK BYPASS VSV/ALL in ACTIVE TEST and operate VSV for EVAP. 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 Figure. If okay, go to step  17. If not okay, go to next step.
  15. Check operation of VSV for pressure switching valve. See FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEMS & COMPONENT TESTING - LX470 article. Replace as necessary. If okay, go to next step.
  16. Check for open and short in harness and connector between EFI or ECD relay and VSV for pressure switching valve, and VSV for pressure switching valve and ECM. Repair as necessary. If okay, check and replace ECM.
  17. Check whether hose close to fuel tank has been modified, and check whether there are signs of any accident near fuel tank. See Figure. Repair 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. See Figure. Repair as necessary. If okay, go to next step.
  19. Check vacuum hoses No. 4, 5, 7 and 8. See Figure. Repair as necessary. If okay, go to next step.
  20. Check hose and tube between fuel tank and charcoal canister for cracks, holes and damage. Replace as necessary. If okay, go to next step.
  21. Check charcoal canister for cracks, holes and damage. Repair as necessary. If okay, go to next step.
  22. Remove glove compartment door. 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 4.5-5.5 volts, check and replace ECM.
  23. Measure the voltage between terminals PTNK and E2 of the ECM connectors. See Figure. Disconnect the vacuum hose from the vapor pressure sensor. Using the MITYVAC (hand-held vacuum pump), apply a vacuum of 1.18 in. Hg (30 mm Hg) to the vapor pressure sensor. The vacuum applied to the vapor pressure sensor must be less than 19.7 in. Hg (500 mm Hg). If voltage is 2.9-3.7 volts when vacuum hose is disconnected, then drops to 0.5 volts or less, it is possible fuel tank cap was not installed correctly. 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 as necessary. If okay, replace vapor pressure sensor.
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