Could not find a better thread, this is about how to fix an issue when Advance Trac icon pops up on the dashboard for seemingly no reason. To put it short: clean your ABS sensor!
I have a 2010 Focus SES that has Advance Trac. This is Ford's ESP + anti-slip system, works well on ice for me. When the system thinks one of the wheels is turning faster/slower than the rest it assumes the hell will break loose soon, so it tries to help by dropping engine power, breaking the wheel it thinks make sense, etc. I felt like the ABS is far more sensitive as well.
Anyway, on a sunny day for no reason it kicked into action while I was taking a 90deg turn with normal, slow speed, say 15mph. The road was dry, so I was surprised. The icon was on, power lost, heavy stuttering from everywhere. I had to turn the engine off to get rid of it. This fun reoccured again, so I drove to an empty parking lot and tried to figure out what exactly triggers it. Turns out, no matter which direction, but a 90+ degree turn with 5+ mph starts it.
I've read several articles about it, could not find anything meaningful, hence my post. Some mentioned the mechanic reprogrammed the ABS, some had to replace the whole ABS unit, some could not fix it ever.
Before I went to a dealership I have dismounted and cleaned all 4 ABS sensors and the issue is gone, did not cost me a $.
Better remove the wheel, you will have easier access. Then find the sensor, which is at the end of a thin black cabel. Unscrew the single bolt holding the sensor, apply some gentle force to remove it and clean the sensor, especially the metal part. Put is back. Do it on the drum brakes as well of course. My sensors were not really dirty, at least I was expecting worse, but seemingly the sensor is a very sensitive electromagnet, probably some small metal dirt could disturb it.
Hope it helped.