If you hook up your back up lights to the plug (usually center pin) when they go on it turns the surge brake off via a solenoid on most.
I learned with my ford raptor (f150) that if tow haul was on then the brake didnt go to lock out in reverse. If tow haul is off it works as it should.
Just a fyi.
2017 Phoenix 920
Ex. USAF Sere Instructor
Proud Dad of a Baylor Bear class of 2022