Trailer Wiring Warning

This lights been coming on in my 18 Tundra for a few weeks now and the dealer can't clear it. Anyone else have this issue and if so any suggestions? I haven't even hooked up a trailer to my hitch or wiring yet

 

sure it has been checked but, any dirt or mud in the trailer wiring receptacle?

 

Clean as a whistle...

This warning light is also on.

 

I'm sure they've been checked, but fuses, relays, and wire connections all good?

 

It appears, and this only a conclusion based on the other trailer connection threads, that the brake controller senses a trailer connection by sending a low level pulse out every few minutes and measuring the current or voltage drop. This is why some folks are finding success with "disconnect" issue WITH a trailer connected by putting a resistor in place.

Yours is the opposite. I'm guessing here that the brake controller is sensing what it thinks is a trailer connection when there is none and then warning when it looses that sense. To me that would point to a bad brake controller OR water/corrosion in the female plug (internally) causing a slight short in the wires to ground or each other.

Possible trouble shooting methods:
Pull plug connection to brake controller - see if warnings still appear.
Check each wire in brake controller voltage to ground. Any wire with no voltage should also be an open to ground by resistance.
Pull out your trailer plug and crack it open. Inspect for moisture or corrosion.
Get a salvaged or second brake controller and swap yours out. See if problem goes away.

YMMV...... Just my 2 cents on the subject.

 

That's a different warning than I was getting with my 2019. Mine was simply "trailer disconnected".

Dealers are strictly "by the book", and no clue what that book is! Did they just try to clear the code or inspect the wiring? I'd start first by hooking up a trailer and see if it works. Check the lights and brakes etc...

Then check that harness connection. Unfortunately it appears proprietary so not an aftermarket better replacement. Looks flimsy as heck to me too!

There is a TSB for the 2019 which fixed my issue.... albeit different...

Good luck!

G

 

Have you had it aligned recently? After my lift I need an alignment and got these warning lights too. There is a sensor on the steering bar that has to be realigned with everything and then the computer reset. Mine was only off 3 degrees and still thru the warnings

 

Update on my trailer brake unit and connections. When I was in over a week ago they ran the diagnostic on my truck and found no errors. So the technician simply wadded a bunch of Dielectric grease into my trailer wiring connectors. The lights came back on within minutes of leaving and I called again to take the truck back in, and wasn't happy. A week later, 4 days ago, the lights did not come back on on my way to the dealer, go figure! Tech took the truck in and found no problems but ordered me a new trailer hookup connection under warranty. It's been four days now and no warning lights have come on since. So must have been some corrosion and perhaps the Dielectric grease displaced any of the water that may have been in there and helped grease the connectors.

I'm supposed to go back in next Thursday for a new trailer plug unit, but they called today and said it was backordered, with no known time frame lol.

There you have it.....we'll see...