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2018 Tundra TRD Trailer not connected warning

Discussion in 'Towing & Hauling' started by Brew1018, May 2, 2018.

  1. Jul 6, 2019 at 6:40 AM
    #151
    Justin Case

    Justin Case New Member

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    Just plugged a single axle trailer with electric brakes into a 2019 for the first time. The plug receptical mount is super flimsy but brakes and lights seemed to work well. Will run it for a while. I kept the P3 from my 2013 just in case.

    Is it a sumple plug and play with this wire harness for 2019 if I decide to remove factory IBC and use P3? Looks like the harness changed from 2013.

    https://www.amazon.com/gp/product/B0781KTCPT/ref=ox_sc_act_title_3?smid=ATVPDKIKX0DER&psc=1
     
  2. Jul 6, 2019 at 7:49 AM
    #152
    Peekay

    Peekay New Member

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    Yes, they reflashed it with that tsb. I'm confident they didn't give me the go around and they certainly did something, because it's now worse than before!
     
  3. Jul 6, 2019 at 7:54 AM
    #153
    Peekay

    Peekay New Member

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    That harness does not work. The 18 and 19s have a different connector. Way more pins than the old ones. My take away from reading dozens of threads on this issue is that at the 18 and 19s dont have the brake sensor light on the factory brake control harness and therefore no connector will ever be plug n play.

    Also, my experience so far is that if you remove the factory brake controller and even if you tried to reset the computer by pulling the battery for an extended amount of time, like in previous years, the truck will still think that something is wrong because the brake controller is not there and give you all sorts of warning lights. If someone has figured out how to get the computer on a 18-19 with factory brake controller, to work woth aftermarket, please chime in.
     
  4. Jul 6, 2019 at 2:06 PM
    #154
    msbaugh440

    msbaugh440 2019 limited, TRD package, cement

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    Well I got my truck back today... nothing is fixed. They said they tried reflashing it and it didn’t help. So they said they’re going to have to order a new brake controller. Coming in on Tuesday this week.

    Not only is it not working, but now I have not one, but two errors on my truck. Brake controller malfunction and pre-collision malfunction. How would dicking around with the brake controller now disable my pre-collision system?? This is extremely frustrating for a truck that has less than 1000 miles... I just need my trailer brakes working...

    A9531974-77B6-48EB-9E04-C8D6D5197982.jpg
     
  5. Jul 6, 2019 at 5:46 PM
    #155
    Kluanie

    Kluanie New Member

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    Did the dealer see the collision malfunction? Can’t believe they would let it out of the shop! I would call the 800 number for Toyota service on this one. They can have the dealer connect on-line and check codes the dealer has no access to. They did that while I was on the phone with them about my wife’s RAV4 xmission faults.
     
  6. Jul 6, 2019 at 9:20 PM
    #156
    msbaugh440

    msbaugh440 2019 limited, TRD package, cement

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    Yes I showed the error to the dealer when I left and they said they would take care of it as well on Tuesday. Weird thing though is that neither of the two errors I had were present when I took it in. Now it’s worse off than when I started. The trailer brake wasn’t working but there wasn’t an error at least.

    I think they dicked with trying to update the computer and messed it up and now it’s gone hay wire
     
  7. Jul 6, 2019 at 10:14 PM
    #157
    Peekay

    Peekay New Member

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    Update on my 2018. Dealer had reflashed with the tsb. I was still getting errors, except even more frequently than before. Last night, I disconnected the brake controller and battery, trying to just dump the stock brake controller. Today, I plugged the brake controller in, and the trailer and lo an behold, it works a lot better now. There are still errors but less frequently than before the tsb and after I got it back from the dealer. I suspect the dealer needed to, but did not, reset the truck after the flashing.

    So now, if I stick it on the correct setting, electric brake 5000lb+,I get errors every time I brake hard, eg, coming down and off-ramp. But once I played around with the settings and set it on electric hydraulic 5000 pounds plus, it only intermittently has errors when I'm braking hard. Like one out of three times instead of nearly 100%. Still not great, but I'm in the middle of a trip and it's good enough for me for now.

    Once I get home, I'm going to add in a parallel circuit for a light bulb or resistor to increase the resistance. This is kind of a Mickey Mouse fix for a new truck, but I don't think the dealer can do any better at this point.
     
  8. Jul 20, 2019 at 5:00 PM
    #158
    Kluanie

    Kluanie New Member

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    Update on brake controller operation: drove from Battle Ground, WA to Gearhart, OR this afternoon, about 150 miles up I-5 to Longview,WA then across bridge to OR Hwy 30. Then to Astoria and down 101 to Gearhart. Brake controller gave no faults. Got 10.0 mpg average according to computer which has been accurate to .1 mpg for the past 2200 miles, ran 65 on I-5 and 60 on Hwy 30. Tow/haul on and S-5 until we hit the winding part just before Astoria, then went to S-4 for better engine braking. Wife asked when she noticed the heavy cross winds on Columbia River if I had forgotten to bring the trailer. Love my new Tundra!
     
    NewImprovedRon likes this.
  9. Jul 30, 2019 at 7:07 AM
    #159
    VintageBikeBuilder

    VintageBikeBuilder New Member

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    PROBLEM SOLVED - A CHEAP AND EASY SOLUTION TO THE "TRAILER DISCONNECTED" ISSUE!!!

    The first time I towed my 5-year-old Airstream with my 2018 Tundra Limited, it was on a 1000-mile trip. The towing system worked great on the way up, but on the way back, I began getting a "TRAILER DISCONNECTED" warning. At one point the warning was going off about every 3 minutes. I checked the connection, cleaned the contacts and it made no difference. From the number of threads I've read, I can see any late model Tundra owner who has a factory tow package and a trailer with LED lighting has or will experience the same this at some point. Like so many others on this thread, I took my truck to the Toyota dealer and they told me the problem was with my trailer. Funny how that's always the simple solution for factory mechanics - it's the other guy, not us.

    Anyway, the solution is simple and cheap. Through some internet searching I found that new Tesla and Volkswagen models and as well as several other manufacturers were experiencing the same issue with their vehicles. When the computers on these new "smart" cars check the pins on the trailer for correct voltage (usually to determine if a light is out), it has been found that trailers with LED lighting do not have enough resistance to provide correct readings - hence on the newer Tundras the "TRAILER DISCONNECTED" warning. I found there are several ways to fool these computers without having to put in a new tow package or build a box with resistors. The Trailer Connector Adapter w/Lamp Out Sensor Bypass is a 7-pin to 7-pin connector that has built in resistors. Here is a link to one on : https://www.etrailer.com/s.aspx?qry=Trailer+Connector+Adapter+w/+Lamp-Out+Sensor+Bypass+-+7-Way+RV+to+7-Way+RV+-+Vehicle+End

    I just completed a 3400-mile trip from Florida to upstate New York and back without a single issue. The best thing is, this little adapter is just $23.95. A cheap and extremely easy fix!

    IMG_5609.jpg
     

    Attached Files:

  10. Jul 30, 2019 at 2:33 PM
    #160
    CO_Native

    CO_Native New Member

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    Just picked up my new 2019 MGM CM TRD Sport to pull our Wolf Pup TT & found this thread. Outstanding work-around if the reflash isn't available or doesn't work. Thanks for posting!
     
    NewImprovedRon likes this.
  11. Nov 11, 2019 at 10:05 AM
    #161
    Yorkwagon66

    Yorkwagon66 New Member

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    I bought a 2018 Tundra Limited just a month ago and I’m having the same problem with the “Trailer Disconnected” warnings every couple of minutes while driving. I’m pulling a 2019 Coleman Camper. I purchased an adapter based on the recommendation above and today is my first chance using it. Well, I continue getting the warning, in fact about a dozen times in about as many miles. Now what do I do?

    Update: Today I went to a local Toyota dealer and had the “Reflash” performed. I had to tell the service rep about the TSB and showed him the reference number. No argument, no comment. Just took my truck back and did the update. Later, I towed the camper back to the storage lot and had no problem. I guess it’s fixed. Thanks to those who posted about the TSB and reflash. Problem solved!
     
    Last edited: Nov 13, 2019
    CO_Native likes this.
  12. Nov 11, 2019 at 3:46 PM
    #162
    jtwags

    jtwags Concrete jungle

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    Go to the dealer and verify they have flashed the latest TSB for this issue. Had my 2018 flashed and no issues towing a 2019 TT with led lights.
     
  13. May 24, 2020 at 9:26 PM
    #163
    dielby

    dielby New Member

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    None
     
  14. May 24, 2020 at 9:29 PM
    #164
    dielby

    dielby New Member

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    I have a 2019 Tundra. Does the same thing for both the camper and the horse trailer. Camper came with a remote brake controller,(wonderful device by the way) and I am now resigned to using it on the horse trailer. Am going to talk to dealer about some sort of refund on purchase of defective trailer towing package. My advice to anyone else. Do not get Toyota’s trailer towing package, go the aftermarket route.
     
  15. May 25, 2020 at 9:33 AM
    #165
    pickupjason

    pickupjason New Member

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    I also have 2019 limited crewmax and tow a 25’ travel trailer. The RF brake controller came with the trailer works wonderfully. I have never connect the trailer directly to the truck brake controller but might try it next time when I bring the trailer out.
    Just want to see if it works or not and know I whether I have a plan B if the RF controller quits on me in the middle of trip.
    In the meantime, I plan to ask dealer regarding the TSB when next service is due.
     
  16. May 27, 2020 at 8:03 AM
    #166
    CO_Native

    CO_Native New Member

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    Knock on wood, 1yr pulling mine, no issues. Maybe they did the TSB before I bought it?
     
    NewImprovedRon likes this.
  17. May 27, 2020 at 8:50 AM
    #167
    sask3m

    sask3m New Member

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    Last edited: May 27, 2020
  18. Oct 13, 2020 at 1:53 PM
    #168
    AK Fundra

    AK Fundra New Member

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    I am new to this forum and have been following this thread since I have experienced this issue. I have a May 2018 CM 4x4 Limited. I tow a 2008 Keystone Hideout with double axel/electric brakes and no LED lights, 4,500lb dry and 5,500 loaded. I have been to the local (Anchorage, AK) dealer over six times for this issue. My visits include: software update, check software and order new TBC, install new TBC, software update and order ECU, install ECU, update software because it didn't take, order new (again) ECU (they assured me this will solve the problem). Currently waiting on new (but different than the other-new) ECU that they had replaced once before. Part should come in soon then hopefully, probably not, fixed. I opened an incident with Toyota USA that was quickly elevated. Talked to a case manager and I asked about wear-and-tear on the truck towing a trailer with no breaks, they said they can't do anything for me. I stated that if this issue is not resolved, I will be asking Toyota to purchase the vehicle under the Washington state (were it was purchased) lemon law. I said I am sick of the trailer brakes going out on our dangerous Alaska highways with no PCS, AEB, and potentially trailer sway. I am sick of this vehicle putting me and my family at risk. If I can't stop this thing in a hurry I am confident Toyota would not take responsibility. He said arbitration will take 30-45 days. I will keep you all posted.
     
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  19. Oct 26, 2020 at 11:37 AM
    #169
    AK Fundra

    AK Fundra New Member

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    Ok. I read my last post and may have come across a little too strong. Don't get me wrong, I love my truck. We have owned four Toyotas and I still have confidence in the brand. I just want it to work. I don't have time to monkey around with this kind of crap that should be sorted out long before I (and all of us) purchase a truck.

    I got my truck back from the dealer last Wednesday. They said they replaced the ECU. I took it out with my trailer and within two blocks I got the error. Once. That was it. I took it on a 40 minute drive and, other than that one error, worked as it should. I had to store the camper because it is winter up here and I had to put the cover on it because it snowed again last night. I am not really sure this thing is completely fixed though. With my luck, next summer we're going to be on a long trip with the camper and the thing is going to go out. Not safe!

    If I make any modifications to the system myself, it could void the warranty. Any suggestions or thoughts would be helpful.
     
  20. Jun 2, 2021 at 12:10 PM
    #170
    SnrDisregardo

    SnrDisregardo New Member

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    Damn, I was hoping for something new on this. I bought a small pop up last year and got a 7 pin to be able to charge the battery while in tow, no brakes on this camper. Got the error a few times while driving then. Come to this year and just bringing it back and forth from my storage spot about 10 miles away, it was much more persistent.
    OK.
    Did some more research and found the TSB, had Toyota flash it, even worst now.

    Mind you this is a trailer using the 7 pin without any brake system. Going to try to hook to a different trailer to see if I have a bad ground somewhere?
     
  21. Jun 16, 2021 at 4:24 AM
    #171
    pmcgeorge1964

    pmcgeorge1964 New Member

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    Thank goodness for this forum! Bought a trailer a few weeks ago and on the trip home with my 2018 nothing but trailer disconnect warnings, got home searched the forums and found this thread. Dealer flashed the brake controller and everything works great now, three hour trip a few days later and all was great. Without this forum I would have spent a lot of time finding the TSB, instead was able to get the job done quick. Thanks all!
     
    Akaklutz likes this.
  22. Jun 16, 2021 at 7:25 AM
    #172
    SnrDisregardo

    SnrDisregardo New Member

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    Glad it worked out for you. I'm still trying to diagnose my issue. I went and plugged into a couple of trailers around town and the warning is gone, but the last time I pulled my PUP, it was going crazy.

    I'm thinking maybe because I didn't have the battery installed on the trailer that it was seeing an open fault? It will take someone with more wrinkles in their brain than me to figure it out I guess.
     
  23. Jun 17, 2021 at 4:26 AM
    #173
    pmcgeorge1964

    pmcgeorge1964 New Member

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    A thought on your issue, Since there are no brakes on your trailer there is no resistance for the controller to see which is how it determines if the trailer is hooked up. The reflash changes the resistance setting.
     
  24. Jun 17, 2021 at 5:55 AM
    #174
    SnrDisregardo

    SnrDisregardo New Member

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    I was thinking it was either that or since the battery wasn't in place. I went last night and installed the battery and still got the same. So that being said, guessing it has some thing to do with brake circuit. I also went thru the TBC menu and made sure to turn it off and still got the warning.

    So, my thinking is to tie the + and - of the brake circuit together?

    Or I'm going to go thru the wiring this weekend and see if there is something I'm missing.

    I bought this so I can charge the battery in to, but the camper came with the 4 pin. It won't be the end of the world, just sucks.
    upload_2021-6-17_7-48-9.jpg

    wiring.jpg
     
  25. Jun 19, 2021 at 7:48 AM
    #175
    SnrDisregardo

    SnrDisregardo New Member

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    Figured mine out! Issue on the camper when I repaired the wires last year.
     
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  26. Apr 28, 2022 at 4:21 AM
    #176
    ChiselnMallet

    ChiselnMallet New Member

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    T-SB-0036-19 software update worked on my "new to me" 2019 Limited.
     
  27. Jul 19, 2023 at 5:20 PM
    #177
    MadTrapper

    MadTrapper New Member

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    Late arrival to this thread. I bought my 2018 from a company that does not tow trailers so I guess this little problem has been waiting for me for some time now. I changed my 2500 GMC for this vehicle and on discovering the problem have been perplexed until I found your Forum. Thanks guys several different paths to follow. I will try the TSB 0039-2019 one first with my local dealer. Perhaps the 30 Ohm resistor next.

    Update, Canyon Creek Toyota in Calgary are not helpful about this, sucking of teeth and promises of big bills. Looks like I'm going to try the adaptor plug first from etrailer.com and the 30 Ohm resistor last.

    The adaptor plug has not worked. Now going to a different Toyota Dealer to see if they can help. Not good vibes so far. I stated that perhaps the TSB was the issue to which the reply was " That's for US models only". I replied. "Then we have an amazing co-incidence that my Canadian vehicle has the same symptoms". Grumpy young lady then booked me in reluctantly.
     
    Last edited: Aug 10, 2023
  28. Jul 19, 2023 at 7:37 PM
    #178
    Jim LE 1301

    Jim LE 1301 Camaro Lover, SSEM # 11,TTC#179

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    Welcome from NY.
     
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