Volkswagen: Check Engine light linked to key?, advance auto parts, driveability problems

Question
Almost a week ago my check engine light came on in my 2003 Jetta. I made an appt. with my dealer to get it checked out but later that night we used my car with my husband's remote/key and the light didn't come on. We then used my remote/key just to see and the light still came on. The next day or two the light turned off with my key too. I am pretty sure it isn't the chip in my key because isn't it a different light? My car has a little over 60K miles on it. Should I keep my appt? What could the problem be?

Answer
hello.  I need to verify the immobilizer unit in your year car.  (audi and vw have changed things here and there)  If you turn you key to the "on" position, (which is the position before start), look to see if a small yellow? light is on the dash in the shape of a key.  If this is there...it is the immobilizer link "scanning" the "chip" in your key...if it goes out (meaning the light goes out) the car has basically accepted this key as a programmed key and will now allow the car to start.  I'll look to see if I have a 2003 around tomorrow and verify which system it has.  Anyhow,... the light that came on.... did it actually say "check engine light" or was it a symbol or what exactly.  One option that I like to mention to folks is that a free service offered at most parts places these days, (like flaps, autozone, advance auto parts, etc.) is the free check engine light scan service.  they may be able to pull the code out of the car for you, that way you can email me back with more info.  Honestly, for your year car I see a lot of ecm/pcm failures...not to say that this is your problem, but I do see many these days.  Are there any driveability problems with your key?  Does your remote operate with your key? (all doors unlock and lock?) Let me know what you find.
thanks,
Shad