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Skyvisions, ASE Certified Technician
Category: Toyota
Satisfied Customers: 14417
Experience:  Toyota Master Diagnostic
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2004 Toyota Highlander: check engine light..the codes that..canister

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My 2004 Toyota Highlander check engine light and vsc light keeps coming off and on. I took it to the dealer and the codes that came up were PO446 and B2799. They wanted to replace the charcoal canister (?) and reset the system for $800. I declined & they said I would never pass inspection. Someone mentioned it could be a loose gas cap and not to top off the fuel. I replaced the cap, engine & vsc lights went out. I went to inspection and passed. The lights came on again 2 days ago. I would very much appreciate your opinion.

The VSC Off light comes on by default with the check engine light. The B2799 means that an unregistered key was used. I would not worry to much about it unless it keeps coming back. Is the p0446 the code that is coming back this time? Auto Zone does free code reads so you do not have to pay the dealer again. The most common problem is the hose that goes to the CCV on the side of the air cleaner housing gets knock off when people change the air filter. Check the hose it is about 3/8 in diameter. The other issue is the VSV on the canister. Given the age it is not likely the canister. Someone does not know how to diagnose or they are too lazy to spend the time to do it right. Let me know about the hose and if you can get the code number again to confirm.



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Customer: replied 7 years ago.
Thanks very much Skyvisions -- appreciate it! I'll take my vehicle to an Auto Zone for another diagnosis and see what comes up this time.

Let me know how it goes.



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Customer: replied 7 years ago.
Checked hose as suggested; it's okay. Lights went out and now came back on again. Autozone checked and gave me following info: Evaporative emission control system vent control circuit fault. Probable: Open or short circuit condition; Poor electrical connection; Faulty CCV vent control solenoid. Any thoughts on what this might mean or how to correct?

There are about three different codes that will fit the descriptions that they gave you. Did they give you any specific code numbers such as P0441 or P0446? The most common problem on the Highlander for these codes is a close canister valve which is mounted to the top/back side of the air cleaner box. If someone just replaced the air cleaner recently they probably popped the 3/8 inch rubber hose off of the bottom of this valve. Open the hood and check to see if this is the case. Let me know if you have the exact code numbers that they gave you or if this hose has popped off as I described.



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Sorry to repeat myself about the hose on the canister I have three of these particular questions going and forgot that I all ready told you about that hose at the air cleaner box. Do you have the code numbers that are reset system this time?



Customer: replied 7 years ago.
Yes, the code number is XXXXX; sorry for not supplying before

No problem, this code will also set one up close canister valve or CCV as it is known by which is mounted to the side of your inbox sticks open. There have been a lot of problems with this valve on the air cleaner. You can remove the valve and vacuum test it and apply 12 V and ground to the solenoid to make sure that it is not leaking. Let me know what you find this valve.