2021 Lariat. Got the new truck 2 weeks ago. Hooked up my utility trailer today and no lights. Message says.
Trailer lighting module fault.
Trailer left turn lamps fault. Check lamps.
Trailer right turn lamps fault. Check lamps.
Anyone have some information on this?
This is using the 4 pin flat plug.

 

Sounds like a ground issue, most likely on the trailer.

 

in the immortal words
from over 20 years of ford trucks...ITS almost always a grounding issue, the system is sensitive to grounds

check all of them first and make sure the lights are actually grounded.
my hauler trailer looses ground often on the LED rear light assemblies. corrosion is a tuffie

 

Had almost the exact same error messages on our 2020. We checked the trailer with another truck, and trailer lights worked. Took the truck back to the dealer, they found a plug that wasn't completely plugged in. Simple, but frustrating.

 

Start at the tongue of the trailer and make sure the white wire is solidly connected to the trailer frame. I've seen trailers work on one truck but not another due to the only ground path back to the tow vehicle was the tow ball.

 

A good possibility. Just slide in under the back,of the truck and make sure the truck’s trailer harness is securely plugged into the back of the bumper-mount trailer connector.

HTH,
Jim / crewzer

 

Got it . Thanks everyone.
It was a ground problem on the trailer. White ground wire to trailer frame had a rusty connection.

 

Good deal, glad it was an easy fix.