1997 Toyota Avalon with a P0446. Charcoal canister has been replaced. What now? on 1997 Toyota Avalon

The charcoal canister has been replaced. The check engine light came back on in about 45 days with code P0446 VSV valve malfunction. Where is this valve and how can I find out how to fix it?

by in Fort Worth, TX on November 15, 2011
1 answer
ANSWER by on June 17, 2012
1. Verify that the 3-way Vacuum Switching Valve (VSV) on the canister operates correctly. When the VSV is not grounded, the Fuel Tank Pressure (FTP) sensor should be connected to the canister side of the system only. When the VSV is grounded, the FTP sensor should monitor only the fuel tank. 2. Monitor the FTP sensor, unplug the 3-way VSV, draw vacuum into the canister and verify that it will hold vacuum, and the FTP voltage will decrease. 3. Test and verify that the purge solenoid and wire harness are all OK. The purge solenoid should apply vacuum to the charcoal canister when grounded. Also verify that the hose from the purge solenoid to the charcoal canister does not leak It is common for the 3-way VSV to stick or not operate correctly or for the charcoal canister to be faulty. The charcoal canister has many check valves and springs built inside, so always replace the canister and 3-way VSV as an assembly. its between the fuel rail and the intake manifold. Unscrew it and there should be your problem. I would post a picture but I do not know how non this post.
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