Audi Repair: a6 2001 coolant temperature red flashing warning, valve cover gasket, coolant temperature

Question
Hi: i just had the valve cover gasket changed and oil changed, when i got my car back it had a huge red flashing symbol my manual says stop the car turn off and fill coolant let car cool. tried this (coolant was a little below min) and still flashing red light. 2.8 quattro ATQ
What should I do? Allow it to cool overnight?

Answer
No it sounds like a coolant sensor has failed, or, more likely, someone has shorted out a wire or forgot to connect one.  If the engine temp is normal, I would go back to the place that did the work and have them correct the problem.  Let me know,  Jan