My 2018 F150 Lariat has the sensors in the tail lights for backup and what ever else they do. When ever it rains, or gets wet then freezes, they will sound off as if there is something behind me. Eventually, they will stop doing that after they heat up, I guess. Has anyone else had this issue, and if so, have you cured it?

 

Check your lights for water intrusion. Maybe throw a thin silicone bead to keep the water out. Water in those can create issues for sure.

 

I have had that happen 2-3 times in 5 years. Only happens when it is quite cold out. No solution other than park in the garage and it goes away.

 

Mine beeps constantly whenever it's cold out and snows, even though they are clear and not obstructed. If you find a solution, please share.

 

Yeah, I was thinkin about doing something like that if my Ferd dealer couldn't tell me anything.

 

Your sensors are in the tail lights? Got a photo? I've never seen that before, my 2020 has them in the bumper, like most I've seen.

 

He said sensors in the lights so I assumed BLIS. No se.

 

He mentioned backup sensors, so I just thought,,,,,,
May be I'm getting goofy or something.

 

The backup sensors are the little round things in the bumper. Moisture infiltration is a common cause of this type of problem. The first thing I would try is to get underneath and clean the connectors with DeOxit and apply some dielectric grease before reconnecting. I've not run into this with my current truck but the 2015 I owned previously would run into this along with false trailer disconnects from the 7-pin which stopped after I eliminated moisture getting into the connectors.

 

So which is it OP? The BLIS modules in the lights? Or the parking sensors in the bumper?