[Caniel]

When that message appeared in conjunction with brake failure it turned out to be the wire that passes through the axle.

On my 2010 Mountaineer, they used what looked like lamp cord zip wire. the insulation had chafed off in a couple of places. That and a slurry of rusty water sloshing about in the axle tube created an intermittent short (usually at the worst moment).

When the brakes failed, I got under the trailer and pulled on the wires going through the axle to make sure they were suspended and not touching the inside of the axle. Fault went away. So I replace the axle wires. Rewired brakes to the back outside of the axle.

Hope this helps.