[A4] new A4 in the family

[Tom Love]

There is now a 01 A4q  1.8T in the family and I have one question upon getting it home.
Oh the 100 mi trip home the tone sounds and the red blinking brake light came on in the dash.
The fluid level is right and the brakes work great. Shut the car off and when re-started there is no light until about 3-5 min of operation. Comes on running straight or turning while on the move without brakes applied.
Any thoughts?
TIA from a long time 5cyl quattro guy.