3 lights simultaneously!
 

I just purchased a 2002 RX-300 a few days ago. As I was driving this morning I turned on the air and all at once the check engine light, CSV and trac control light came on.

It is still under dealer warranty but I would like to know if anyone knows what causes this. I am afraid they will just reset the codes and not fix the problem. Any input would be appreciated. Thank you.

Do a search on those 3 lights together. Take some vacation time though because you'll need it. They are a very GENERIC combination and can be triggered by a multitude of things, some of them very simple. They don't necessarily have ANYTHING to do with those 3 things.

Welcome to ClubLexus!

Those three indicator lights coming on together are the "Check Engine Light" (CEL) indication.

As you use the search function, you will see that there are inexpensive OBDII (on-Board Diagnostics 2nd generation) code readers for sale or you can get the codes read at some auto parts stores for free.

It could be something as simple as not tightening down the gas cap enough. In my case, it has always been an emission sensor burning out, but it could be a wide variety of things.

Welcome to Club Lexus! Post some pictures of the RX!

Take it back, and have them repair it. It's their problem now. Just demand that they fix it, and ask for them to give you the code, this way you can post it up here and we can help further. Without a code, we are just talking about random things that may or may not be the root cause of the CEL.

For example, sometimes the hose on the back of the air filter housing can come off, and cause a CEL. In this case, that kind of makes sense, since the car was just sold, maybe someone replaced the air filter in order to get the car into tip-top shape and in doing so accidentally knocked the vacuum line off.

Okay, so I took it in this morning and they told me that codes were: 400, 441 and 446. Said thet whoever changed the air filter accidentally disconnected the EVAP hose. They re-attached the hose and reset the CEL. My question now is, "Why did it take 5 days for that light to come on"? They told me that system does not test very frequently is the reason for the delay. Any input would be appreciated.

Extremely common. That's the rreason I do all my own work. If these guys are supposed to be the "Professionals" (better be for what they charge per hour) and they mess up as often as they do on COMMON things, why would I want to pay them over $100. an hour to "mess up"? I spent my life working in automotive work and saw more damage done in the the shop than you could shake a stick at. Most often denied that they had anything to do with it. A sad situation for those that can't do their own work. There are honest and competent mechanics, just not near enough of them.
On the last question, it is true that many things don't set a light and throw a code until it has gone on for a # of "cycles". Otherwise you'd be going nuts with CEL's if every time it hiccuped it set a light. The delay (on many things) is a "retain your sanity" delay. :D