2018 Tundra TRD Trailer not connected warning

hi all - I’m a brand new Tundra owner and I am very happy I found this forum! We bought a new 2018 TRD off-road specifically to tow our 4000 pound 2017 travel trailer. The first time we hooked up the trailer everything seemed fine m...UNTIL we started moving. Then the Tundra gives a warning - “trailer disconnected”. When that happens the system seems to reset and the brakes do not work. The lights, brake lights and blinkers all continue to function even though the Tundra says trailer disconnected. As soon as I stop the trailer comes back “online” and the brakes work. I can roll forward and it stays connected but as soon as I give it gas it gives the same warning. The trailer is very new as well. The dealer has the truck and says everything seems fine but they are going to try and hook up a different trailer to see if they can replicate the issue. Has this happened to anyone? I love the truck, maybe I should have get a P3 or other non factory trailer brake? Thank you for any feedback.

 

I had a similar problem. Bought a P3.
Finally had the dealer drive with truck and trailer. They found a bad magnet on one of the wheels. Only failed when it got hot. Dealer said they would not have found the problem if not for the P3.

 

Thanks guys! Very helpful. I’m going to try the prongs first and if that doesn’t work, I might see a p3 in my future! I truly appreciate it!

 

Were you able to get your issue resolved? We are experiencing the same problem with our 2018 Tundra and brand new travel trailer. The dealership has both our truck and trailer now.

 

Well, I wish I could say it was "resolved" without an issue.

Toyota had my truck and trailer for a few days. They tested the truck, said it passed and all connections were good. Then they hooked up own their car trailer and it worked and it's the trailer and not the truck.

So, I took the truck and trailer to an RV dealership and low and behold, the trailer checked out just fine there. They then took my truck and hooked it up to a 2018 trailer and the truck threw the same "Not connected" error and I was there. I really thought it was the truck all along. Lot's of software and technology, whereas the trailer is pretty basic, even though it's pretty new.

Ultimately, I was in a pinch because I had a camping trip planned last weekend, and it was planned ages ago. So I ended up getting the Prodigy RF Brake controller. Not cheap, but funny enough it works just fine without any changes to the trailer. Hence it's the truck. I also got the RV dealer to document the issue and the test they did with a different trailer.

I have reached out to the dealer and they are going to " work" with Toyota on resolving my issue. Which in my opinion, is getting me my money back to cover the Prodigy. The Prodigy works great and has brake boost which ultimately is probably better than the Toyota brake. Another nice feature of the prodigy, it plugs into your cigarette lighter, so there is no damage to my dashboard.

Good luck! Please let me know what you hear. Once / if I get anywhere with Toyota I will update this thread!

 

Did you get a plug and play wiring adapter for your prodigy? If so, which one? I've ordered the 3017-P, but am having doubts if it will fit

 

Sitting at my dealership with the same problems.

 

Bought a 2018 Tundra about 2 months ago. It has the towing package and I got the exact same problem. I took it to the dealer's service department and they tested it with a trailer simulator that plugs to the bumper connector and drove around and of course everything checked out okay. But the only question the dealer could not answer was: How does the breaking system know there is a trailer connected/disconnected? There is nothing on the connections (electrical or hitch connections) that shows any additional sensing system attached. I checked everything on two different trailers: grounds, 2 new 7-blade plugs, bulbs, wiring connections and used a separated battery to check each circuit. On the truck, I unplugged and inspected the 7-blade connection for corrosion and visually inspected the wiring bundle (I lowered the spare tire). And everything checked okay. I test drove with one of the trailers and tried all the different trailer configurations and the Tundra continue having the same problem. I noticed that some times it connected and disconnected, I was able to temporarily re-establish connection by actuating the manual control. I also noticed that the gain button was not changing the values correctly. The gain button was intermittent and I had to keep pressing it to be able to change the values up (plus). For the brake controller to work correctly, you have to set the gain value first (I set it at its max (10) value) then I was able to lock the wheels using the manual mode. But at the end, it continued to disconnect for no reason. My guess, is that the problem is in the truck brake controller system. The trailers have very simple electrical circuits that consists of lights and magnets. The Tundra's brake controller system must be measuring the flow of electricity to sense there is a trailer hooked up and may not be sophisticated enough to function whenever there is a change on the trailer circuitry, and it is only programed to "disconnect" whenever there is a change. The problem for me is that the dealer uses a trailer simulator to verified that the system is working, so I have to prove that the problem is not the trailer. My next step is to go to a trailer dealer and probably pay them to let me hook up couple of new trailer and document the results.

 

Thanks so much. At least I know it’s not just me. The aftermarket controller is working really well and I’m continuing to press Toyota. If I make any progress I’ll let you know. Thanks everyone!

 

Count me in as having exact same problem w/my 2018 TRD OffRoad 4x4 TBC. will take back to dealer and see what they offer.
Btw, I have confirmed that trailer brake system is working fine - using my old Sequoia with a Tekonsha controller.

 

Just finished a small trip and the Toyota trailer brake kept going off and on. Probably going to just use one I bought for another vehicle. Hopefully someone gets theirs fixed.

 

I just hooked my trailer up and drove down the street and back. So far mine is working fine.

 

Hooked my 17' camper up this weekend and mine (2018 trd off road cm ) is doing it too. the service department doesn't believe its the truck. I towed that same trailer with my 16 Tacoma with 0 issues. Have you guys had any success? headed to the hills next week.

 

I have the same issue today. Brand new 2018 Tundra Limited hooked up my trailer as soon as I hit the gas I get a trailer disconnected message.

I used the trailer last week in a Nissan titan without a problem so I am pretty sure it is the Tundra have a problem.

 

did the 3017-P work for your 2018 tundra?

 

I got the same warnings on my 2016 pulling a dog trailer with no trailer brakes. It was caused by a short somewhere in the aux electrical system of the trailer. I built a 7 pin jumper cable that eliminated everything but the lights and...no more problem. Same trailer on two other non-Toyota trucks with factory trailer brake systems, no problem. Small trailer electrical problems can cause error messages just like small sensor problems on your truck can cause wild error messages.

 

Hi Over the LINE, can you explain more what you done? In your case which one has the problem the Tundra or the trailer? Does your truck have the built in brake controller as well?

 

Do you have an update? Was your issue resolve?

 

The problem was a short or wiring fault on the trailer side. The trailer does not have brakes. It caused my Tundra to throw the same or similar warning. I fixed the issue by making a short trailer jumper with a 7 pin male (on the truck side) and a female to accept the trailer side (what would normally plug into the truck). In between the two I only connected marker and brake/turn so the short in the aux electrical system was removed.

The side note was, this trailer does not throw fault warnings with two non-Tundra trucks with factory trailer brake controllers.

 

if you have an IBC installed from the factory, do you still have the adapter plug under the dash to connect an aftermarket IBC like the P3?

 

I think I found it under the kick panel the pins all line up.
I unhooked turned the key over and it shows the tire warning but no brake controller issue. If I unplug the ibc it tells me their is a fault

Giving it a shot . Has this controller and harness from my 3rd gent tacoma.

Showing the esp console. (Irritated the factory system sucks!)
Harness number
No trailer connected and tells me their is a fault.
Apply trailer brakes manually and it overrides.

Any insight? This is an 18 cm limited.

 

Did you keep the IBC intact or you remove/disable it? I might just buy a Prodigy RF Brake controller as well.

 

I have tracked the issue down to my trailer. My trailer is almost brand new (16') and never had an issue with it when my tacoma pulled it. One of the magnets is shorting out the system and resettingv (disconnect / reconnect after brake application) . I pulled my dad's new trailer today without a single issue. So I would imagine this is truly a trailer related issue and tundras are extremely sensitive to voltage changes. I would be interested in others feed back.

 

Grrrr. Getting the same problems with my '16. Have a BRAND new flat bed trailer with brakes...been working fine for weeks. Today, for no reason...no brakes. Lights work fine...7-pin is groovy.

Just what I need--more trouble shooting before a big trip. Grrrrr

 

I never could resolve my trailer issue. Ended up with the Tekonsha 90250 RF brake controller and it worked just fine. Actually with the boost it was a better option!

 

Oh. That’s the next tasker. For a brand new trailer, the tires were barely nutted on. The axles themselves were hardly secure. I can only imagine the wiring...

 

Never got it resolved...I left the IBC but use the Tekonsha RF brake controller instead.

 

I got the Tekonsha RF controller. It. Works great!

 

I'm a tech at a Toyota dealership. I had an 18 platinum tundra that would have "trailer disconnected" while driving. Ended up swapping the trailer brake control ecu from another tundra, and the problem went away. Ended up replacing the bad ecu.
Hope this helps others.