Last couple of days, the red "BRAKE FAILURE" light started coming on at high speed on the interstate. I thought it odd, since the only times it had ever come on before was shortly before I replaced the master cylinder.

The light flickers on and goes off for a split-second when I go over a bump or on acceleration (or some decelerations).

The brakes work the same as before; they are good.

The symptom seems to go away in city traffic, or when the weather is cool, or, quite frankly, at random intervals.

I think there's a loose wire somewhere. Thoughts?