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Home >> Toyota >> 1998 >> RAV4 Base, 4D Utility, AWD, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes >> Self-Diagnostic Tests >> DTC P0441: Incorrect EVAP Purge Flow DTC P0446: Vent Control Malfunction >> Diagnosis & Repair (Using OBD-II Scan Tool)
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Diagnosis & Repair (Using OBD-II Scan Tool)

  1. Check EVAP VSV, vapor pressure sensor VSV and vapor pressure sensor wiring harness connectors for damaged pins, corrosion and loose wires. EVAP VSV is mounted on air filter housing. Vapor pressure sensor is located on firewall, near brake master cylinder. Vapor pressure sensor VSV is located on top of charcoal canister on left side of engine compartment. Repair as necessary. If connectors are okay, go to next step.
  2. Check all EVAP related vacuum hoses for cracks, looseness and correct routing. Replace vacuum hoses as necessary. If vacuum hoses are okay, go to next step. For proper vacuum hose routing, see VACUUM DIAGRAMS article.
  3. Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Backprobing ECM connector, measure voltage between terminals No. 1 (Yellow wire) and No. 9 (Brown wire) at ECM E5 connector. See Figure. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, replace ECM.
  4. Backprobing ECM connector, measure voltage between terminals No. 7 (Blue/Yellow wire) and No. 9 (Brown wire) at ECM E5 connector. Disconnect vacuum hose from vapor pressure sensor. Connect a vacuum pump to sensor. If voltage is 3.0-3.6 volts without vacuum applied and 1.3-2.1 volts with .59 in. Hg (2 kPa) applied, go to step 6). If voltage is not as specified, go to next step.
  5. Check for open or short circuit in wiring harness between vapor pressure sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair wiring as necessary. If wiring harness is okay, replace vapor pressure sensor.
  6. Disconnect EVAP VSV vacuum hoses. VSV is mounted on air filter housing. Apply air pressure to VSV port "E". See Fig 1. Air should not flow from port "F". Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Connect jumper wire between ground and terminal No. 22 (Pink wire) at ECM E4 connector. See Figure. Air should flow from port "F". If VSV functions as specified, go to step 9). If VSV does not function as specified, go to next step.
  7. Check EVAP VSV operation. See EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM/COMPONENT TESTS article. Replace VSV as necessary. If VSV is okay, go to next step.
  8. Check for open or short circuit in wiring harness between EFI main relay, EVAP VSV and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair wiring as necessary. If wiring harness is okay, replace ECM.
  9. Disconnect vapor pressure sensor VSV vacuum hoses. VSV is mounted on top of EVAP charcoal canister. Apply air pressure to VSV port "E". See Figure. Air should flow from port "G". Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Connect jumper wire between ground and terminal No. 8 (Red/White wire) at ECM E5 connector. See Figure. Air should flow from port "F". If VSV does not function as specified, go to next step. If VSV functions as specified, check charcoal canister. See EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM/COMPONENT TESTS article. Replace canister as necessary.
  10. Check vapor pressure sensor VSV operation. See EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM/COMPONENT TESTS article. Replace VSV as necessary. If VSV is okay, go to next step.
  11. Check for open or short circuit in wiring harness between EFI main relay, vapor pressure sensor VSV and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair wiring as necessary. If wiring harness is okay, replace ECM.
Fig 1: Identifying EVAP Vacuum Switching Valve (VSV)
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