Check Engine Light?

[LSHANDY at aol.com]

Dear Fellow Audi (Quattro) Drivers.  I am still a new member.  I just bought 
my first Audi A 1993 90 CS Quattro Sport about three days ago.  The purchase 
was one of the best I've ever made.  I love the car already.  I am still 
learning about my car and that is been made possible by reading all of your 
messages.  I read everything I get in my mail box every day.  The following 
is a current question of mine.  If any of you know the answer I would love to 
hear it.
My Check Engine Light came on tonight on the way home while driving on the 
freeway.  I kept an eye on my Temp. but no change.  No loss of power or 
anything really weird, just that bright yellow light.  As soon as I got home 
I shut off the engine and then re-started it again.  The light went off with 
the engine and then didn't come back on again.  My question is, What is it 
that would cause that light to come on??  Is it Low fluid somewhere or 
possibly a loose wire??  
I would love any advice any of you may have.  I just had the car inspected 
yesterday and it passed, however we all know that that doesn't really mean 
anything.
Well that's about it.  I would love to hear what any of you think I ought to 
be checking in my engine for why this light may have come on.  Thanks again 
for the great education all of you veterans are giving me on my car.
P.S.  A little side note.  Starting Monday 8/28/00  I will be starting work 
selling cars at an Audi Dealership.  I think this will help my knowledge of 
Audi's grow even more.  Thanks again.
Brandon.