The sensor in the fuel filter housing is bad. I had the same problem on my 2003 6.0L F-350. I had the Ford dealership change the sensor ($110.00) and I have not had the light come since.
The water separator for a 2003 Jetta is built in with the fuel filter. It is located at the bottom of the filter, and should be drained every 10k miles. If you are performing your normal 20k service maintenance you probably don't need to worry too much, due to the fact that you change the fuel filter every 20k miles.
186,282.4 miles every second.
You should drain & replace your coolant at least once every 100,000 miles minimum.
I usually drain it from the oilpan drain plug, but every 4th oil change, I also remove and check the whole oilpan. (that's every 12,000 miles.) I just like to keep an eye on everything so it runs better.
Light travels 186,282.397 miles every second.
190,008,045 miles every 17 minutes.
Roughly 186,000 miles every second.
Every 1,000 miles, or when the light comes on.
Only need drained when water in fuel light comes on. Filter needs changed every 15,000 miles or once a year.
Change the oil. It comes on every 10,000 miles.
Every 15,000 miles what do you need to check.
The light should be reset after each oil change. It is programmed to come on every 7,500 miles. I surely would Not exceed that.