It happened today to my 2002.5 1.8T, up here in frigid Toronto (-23 celsius this morning). No problem warming up and driving to work this AM, but it came on after I fired it up to drive home at 6 PM (-14C). I let it warm up too long (I know that's a no-no, but it was soooo cold the oil in the gearbox felt like glue) and when I drove off, on came that cursed yellow engine icon, First tie in over a year. I thought VW had fixed that hassle by re-programmming the black boxes. Maybe it was just a small misfire that triggered the CEL, due strictloy to tye super-cold weather. I have been told the CEL can turn it self off on its own, I don't feel, like going to the dealer just to get it turned off. Engine ran perfectly all the way home (45 minutes at city-boulevard speed).