I wanted to get (2) 6V batteries instead of one 12V and I wanted them to make this mod there. I went to drive off the lot and got "Trailer Disconnected" error on my 2018 Tundra with factory tow package. I got out and checked connections and all lights worked so I figured this to be a logic error something related to the electric brakes sending bad info to my brake controller. 

After their guys studied this for several hours they came up with it must be my truck. I pull two other trailers with my new truck and I have another tow vehicle that I have never seen this error after two TT, a Cargo trailer and a flat bed. Still, I think the RV guys are pretty comfortable in their diagnostics and troubleshooting conclusions. 

I'm going to hook my truck up in the morning to a known good trailer (as my truck was known good prior to the connections this morning) and figure this out. My first instinct would have been to do that on the lot prior to suspecting hardware and mechnical (other than brakes) for a problem that I would suspect to be logic or electronic...I guess that's why they call them mechanics. I digress. 

I will figure this out in 30 minutes at my shop where I have multiple tow packages and tow vehicles, at least to the point of knowing where the intermittency is being generated but my concern is (with a BRAND new unit) that 1.) perhaps they feed some voltage back to my controller to take it out  (easy to figure out) 2.) that there is some logic that is created from voltage levels that are standard to the Tundra and all of my other units, but not to the R Pod) i.e. I have no other towing vehicle with all LED lights; could this impact the resistance of the unit and give a different current reading to my trailer brake controller? 

Well, I could go on but I think if anyone has seen this problem, I don't need to . " Lil' Hep"??? Oh, glad to be a new PODDER (as soon as I get it working) 3 hours of driving with that damn alarm going off every few seconds was definitely a form of Chinesse water torture! ;-)~ Jesse Deese

Two things.

First, "some" trucks may have an issue with the low current that the all-LED lighting system on an R-pod presents. I frequent a Ford pickup forum, and some people that see this have added a resistor (or two) on the running lights to increase the current flow. Our truck does not have this issue with the R-pod (or other trailers we tow).

Second, one time I had not seated the 7-pin connector completely and had a similar condition. After that, I double/triple check the 7-pin to make sure it is plugged in ALL the way, and the dust cover comes down and latches.

parts replaced: 

Stitch, trailer B (?) 84391-0c010

Relay, Brake Control 89547-0c020

This was warranty work in my case so zero dollar for repairs. I hope this helps

Originally posted by harrypodder Not a Toyota but my 2009 F-150 with a tow package did not have the relay installed for electric brakes. Found it in a package in the glove box along with a brake controller adaptor. You would think since it comes from the factory with the tow package they would just install it because it has it's own slot in the relay panel that was empty not replacing an existing relay. If I had not found that pkg I'm sure similar problem would occur.

Mine had the relay installed since it came from the factory with a brake controller.  If the controller has to be installed the installer should have instructions or knowledge to install the relay during installation.  I think the owners manual has instructions about this as well.