This light came on about three years ago and I've spent hundreds of dollars trying to get it fixed. The code says it is in the Evaporative Emission Control System. So far, I've replaced gas cap twice, the oxygen sensor once, the emission control valve once, and some tubing rerouting fix. Nothing has worked. I have now come to the conclusion (after reading several camry forums) that this light problem is common on '99 Camrys, is seldom fixable, and is commonly addressed by replacing every part in the emission control system until you get lucky.

Some questions:

Does Toyota have a method to identify which part, and only one part, that is defective?

Does Toyota guarantee it's work, so that no matter how many parts they guess at, you only pay for the one that worked?

Is there a way for the consumer to reset the light so each attempt (e.g. gas cap) doesn't cost $75?

Will the light go off without paying the $75 fee if the problem is resolved.

Normally I wouldn't care because the light doesn't effect the vehicle's performance, but I'm moving to Virginia where it will have to pass emission tests. I'm just wondering if it will have to be junked at that point.

Thanks.

 

What is the exact code(s)?

Toyota might be better at diagnostic work but will not guarantee to do the job right the first time or not charge you if the problem is not solved.

Try disconnecting the battery or EFI fuse to reset codes. Keep in mind if disconnecting the battery; if the radio with a theft prevention system and code set it will need to be inputted to get the radio to work. And if the car has a Toyota engine immobilizer theft system it will engage or other alarm systems may go off after the battery is reconnected.

 

Thanks for the reply. The code is P0446.

Thanks.

 

P0446: Evaporation Emission Control System Vent Control Malfunction.

There is a long of list items that could cause this code.

The computer has detected condition is one of the below:

No continuity between the vapor pressure sensor and charcoal canister (hose plugged or leaking).

No continuity between the vapor pressure sensor and gas tank (hose plugged or leaking).

Once the EVAP system has been purged pressure in the canister is equal to the atmospheric pressure (a leak).

Toyota has a TSB on this code to inspect the hoses between and pipes between the EVAP VSV and charcoal canister for leaks. And replace the vapor pressure VSV and canister.

Suggest starting out by checking the vapor pressure VSV, this is the vacuum valve on the canister.

 

I appreciate the answer. But here lies the problem: the light doesn't point to a problem, but a list of POSSIBLE problems. Therefore, Toyota gets to run through the list replacing all the parts, doing all the labor, being responsible for nothing. Imagine a carpenter coming to your house saying "Well, I will replace your roof first, then if that doesn't work I'll replace your chimney, then if that doesn't work I'll replace your foundation, then......."
So far, what I haven't found on this, or any other forum, is a diagnostic method for determining which part isn't working.&nbsp\\; And as I said earlier, other forums are full of horror stories of '99 Camry owners spending tons of money and NEVER getting the light permanently off , they just gave up. In Cumberland County, Maine, your car can't be inspected with this light on! That means your 9 year old car is junk because there is not a dependable way to fix it.&nbsp\\; I was lucky, I replaced the gas cap (for the second time), got the light reset, then got it inspected.

I'm willing to replace any part on the car to avoid junking it, but I expect a guarantee that whatever they do will fix it and not be a complete waste of money. I don't think that's unreasonable.

 

Unfortunately the design of the EVAP system and trouble shooting system does not allow pin pointing the problem. To have such a system would add more complexity and cost to the car. The ODBII system still saves a lot of time and energy compared to non-built in diagnostic system. It was required by the EPA to help mechanics diagnose emissions problems.

If a good Toyota mechanic they should not have a problem fixing the car as the Toyota OEM shop manual has detailed info on checking each part in the system. The system can even be exercised and tested using the Toyota diagnositic tool.

You should be able to expect the Toyota dealer to replace the correct part, however dealers can be just as good or bad or greedy as other businesses in doing work.

These EVAP problems are common and typically resolved. The system is designed to meet EPA requirements, as such if Toyota designed the system to fail after 9 years without a means of repair the EPA would sue them. They did this for model years 1996-98 forcing Toyota to extend the warranty on the EVAP system.

The code although not as specific as you would like it still points to 3-4 parts, all of which can be tested.

 

This video shows how to accomplish the test required to track down and isolate the cause for the P0446 code on the Camry. This is not easy to do as the canister should be removed for better access as it resides above the rear suspension just forward of the tank. The car must be put on a lift to do this unless you like the dirt alot. Then the tech can be more sure of what item to replace knowing what has failed the test. This is done after a complete inspection of the vacume hoses and other components.