I have a 2006 ford five hundred

usually means theres a problem with traction control

What do I do

take it to the dealer or a shop to have them correctly diagnose the problem. usually its a bad sensor

I had the same issue a year ago. The problem is in AWD system. There are two parts of the system that is where the problem lies. One is the module and the second is some kind of mechanical part. My Ford dealer recommended to change the module first as it was only $800. But that wasn't the problem. It was the mechanical part that had gone bad. That was $1400. And as you can guess they can't take out the module as it's now a used part. So $2200 later the light doesn't come on any more. But it is dangerous not to have it fixed, especially if you live within the snow belt.