This happened to me in my wifes '11 V6. Same thing..brakes pulsating, loss of power, twitching left and right with the light on the dash blinking. Service advancetrac light has been coming on since 30K miles. Was 1200 miles from home the first time it came on and dealer said cant diagnose unless light is on, just keep driving it. Has been to local dealer several times with this issue, still not fixed. Cannot duplicate when at the dealer. 54K miles now and dealer says its NOT under warranty! Contacted Ford and dealing with a regional rep now and waiting for it to be scheduled in. Funny things is, I was on the phone today with RR and headed to dealer...light was on! He said take it to Service Mgr and have them look at it. Got to dealership and told him per RR that my car needs to be looked at. He got grumpy with me and said "I don't take orders on when I have to look at someones car." I explained to him the situation and he said I have to make appt. Blown off again. Got to go back sometime next week with car, get a loaner, pay $88 for a diagnostic test that more than likely wont show anything AGAIN cause light prob wont be on. Wouldve been WAY easier to have scanned the car today. I'll update later.