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2018 Tundra TRD Trailer not connected warning

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

  1. Jul 28, 2018 at 4:25 PM
    #61
    Blackfly

    Blackfly New Member

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    Canadian owner here. Same problem with the warning
    2 trailers. One has brakes on all 4 wheels the other on only 2 wheels. They are all in parallel. I will check the various resistance values since it should be much lower with the 4 magnets than two. Trailer wiring all new, magnets new.
    My comment is that this is a HUGE safety issue for Toyota. I tow regularly north of Lake Superior with long hills. Recent experience was scarey with the IBC turning the brakes off with the disconnected warning while going down hill and then turning it on and off randomly with the trailer disconnect /connected warning.
    Problem is you are then only using the truck brakes when wham the trailer brakes comes on unpredictably.
    Wet road with locked trailer wheels equals skids which come and go. Gain set at 8 with a 6350 kg combined weight measured at a scale. No fun.
     
  2. Jul 29, 2018 at 6:04 PM
    #62
    TundraRunner481

    TundraRunner481 Kinda New Kinda Not

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    In case it helps anyone, have an 18 here made 11/17, so an earlier 2018. Knock on wood, towed twice, one longer trip to and from, and then to store it, no issue.
     
    NewImprovedRon likes this.
  3. Jul 30, 2018 at 10:35 AM
    #63
    AmateurWheels

    AmateurWheels New Member

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    Ironically I did just this, took a trailer clearance light and added it to the brake circuit (parallel). Taped it by my junction box. Brakes work fine, no random disconnects now. Essentially it changes the resistance the ECU sees. My mfg date is 5/2018

    Single axle trailer, LED lights in trailer, stock bulbs in truck.

    Original trailer I commented about a couple weeks ago got totaled this weekend 2017, and was just replaced by the same trailer a 2018. Same issue. Just emailed my dealer, waiting for my appointment.

     
  4. Aug 3, 2018 at 11:12 AM
    #64
    AmateurWheels

    AmateurWheels New Member

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    Dealer just called, ordering ECU for brake controller. Should be in Tuesday.

     
    NewImprovedRon and jdavis75 like this.
  5. Aug 11, 2018 at 5:30 PM
    #65
    DvH297

    DvH297 New Member

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    Update after going to RV Service: had brake system checked out, all functioning correctly. Magnets good. They towed it around with their own truck and brakes worked as expected. Voltage/resistance all within acceptable ranges.

    We then used their TBC tester on my Tundra. The Factory IBC did not throw any errors and worked correctly. Then we hooked my Tundra up to two other trailers in the yard randomly. Applied the manual override. The IBC worked. No errors from the IBC from either two(!). They were completely mystified too.

    So, my tests showed that the Tundra IBC is very sensitive to something that my own trailer's wiring does. It is functioning as designed, but is overly sensitive to its own test loop.
    I think the recent posts (above) about adding resistance to the wiring may be just the clue! And/or getting Toyota to put the newer IC board in. (but if part # is same, how do we order the new one?)

    As an aside, I decided to try and mount my own Tekonsha P3. Ordered the standard Tundra 3017-P adapter harness. When I pulled the IBC out, imagine my surprise when the harness plug was different than the normal connector! The '18s apparently use a new connector. Shown below.

    Really frustrated at this point.
    Will keep trying - 1st with adding the resisters as shown by KeithD.
    Tundra_2018_OEM_wiring-pin.jpg
     
    Last edited: Aug 11, 2018
  6. Aug 13, 2018 at 11:38 AM
    #66
    woodywoodward

    woodywoodward New Member

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    bone stock
    My new controller didn't change a thing. Just got back from a trip. any suggestions?
     
  7. Aug 13, 2018 at 11:40 AM
    #67
    PA452

    PA452 New Member

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    Did a little trailer pulling yesterday. Happy to report no issues. Hope it stays that way and I can sell my Tekonsha P3.
     
  8. Aug 15, 2018 at 10:41 AM
    #68
    AmateurWheels

    AmateurWheels New Member

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    Just got back from the dealer. My 5/2018 Tundra just had the Brake ECU replaced. All is resolved now. Drove it 30 miles, no disconnects. Be persistent. If no resolution, try a different dealer or call Toyota Corporate. They have tickets open regarding this issue at corporate. I'm lucky, and have a good relationship with my local dealer. I have yet to try it with my other two trailers which had no issues with the old ECU, but if there is an issue I will report back. If someone needs the information of a dealer in SW Michigan that will take care of the issue, feel free to PM me.
     
  9. Aug 15, 2018 at 10:51 AM
    #69
    AmateurWheels

    AmateurWheels New Member

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    Question -- When adding a IBC to a truck after the fact, are you just purchasing the control module with the buttons you press, or are you purchasing the control module, and the ECU?
     
  10. Aug 16, 2018 at 6:17 PM
    #70
    JoeDenver

    JoeDenver New Member

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    Big thanks to Jason! He told me I should be persistent and make Toyota change my ECU and finally today they did and all the way home at least 10 miles and no errors. Took 3 months and missed out on almost the whole camping season. As others have said Toyota needs to do a recall.
     
    NewImprovedRon and GoCboys like this.
  11. Aug 18, 2018 at 5:53 AM
    #71
    JoeDenver

    JoeDenver New Member

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    For anyone having this problem my trailer is a single axle and the dealer said that it has a different voltage than a dual axle and that the trailer sends too much voltage for the IBC thereby disconnecting and reconnecting.
     
  12. Aug 21, 2018 at 12:16 PM
    #72
    WrigglingWilly

    WrigglingWilly Well used Member

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    Sorry for the delay, I towed with mine yesterday for the first time. A large uhaul open utility trailer, 12x6, towed 180 miles up the I-70 and back down to Denver loaded with kayaks, maybe 450#s total of cargo and 1750#s of trailer. I have no issues to report. Mine was made in May 2018.
     
  13. Aug 21, 2018 at 12:41 PM
    #73
    sprtbkr

    sprtbkr Average Member

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    TRD Wheels & Tires, Double Cab Fold-down Back Seat mod, LED Interior Lighting, Turned Off Seat Belt Chime, Franken-key (Flip Key), Duraliner Bed Liner, Bed Rails, Hood Wind Deflector, Console Gun Safe, iBoard 5" Running Boards, TRD Sport Bed Vinyl, Fortin Evo One Remote Start with Mycar Cellular Module, Plasti-dipped Badges and Bumper End Caps, Tinted front windows, Extang Solid Fold 2.0, Pop-N-Lock, TUNDRA tailgate inserts, RCI Powder Coated Skid Plate - coming soon - 12” android radio, oemaudio+ Reference 500Q, under dash/seat lighting.
    I tow a 3000# Forest River R-Pod travel trailer with my 2018 Double Cab, manufactured 11/2017, and I use the trailer brakes and have had no issues at all. I've probably put on 1000 miles of towing on since I got my Tundra in June.
     
  14. Aug 21, 2018 at 9:00 PM
    #74
    DvH297

    DvH297 New Member

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    Good news! - tried KeithD's fix, using the 5W load equalizer that WAtundra4x4 suggested. Bingo! no more 'Trailer Disconnected' message and the TBC worked.
    Got these on Amazon. $15.

    Thanks everyone who contributed!
    IMG_3868_5W_load_equalizer.jpg
     
  15. Aug 31, 2018 at 8:13 AM
    #75
    MostlyStock

    MostlyStock New Member

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    Hi everyone. New to the site but have read through the thread.

    Count another 18 Tundra in for having a trash IBC. Manufactured in 11/17, took to dealer where they swapped ECU and trailer brake switch... not fixed. Opened case with Toyota Customer Experience (1-800-331-4331, feel free to open a case if you have the same issue to add some leverage on their engineers to fix the issue). I was informed that my single-axle travel trailer worked with a 2017 Tundra on the lot but didn’t work with 2 other ‘18s. The logic from Toyota was that all of the 18s are operating as intended even though it isn’t in my case. Still have not received an explanation of why exactly it works with a 17 and not with an 18.

    Anyone know how to wire up a tekonsha P3 without voiding a warranty? Sorry if I missed that in the thread somewhere.
     
  16. Sep 1, 2018 at 7:06 AM
    #76
    JoeDenver

    JoeDenver New Member

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    It took 3 months to get mine resolved. Don't spend money on the trailer like I did. Make Toyota fix it, that's the best solution. I finally got mine fixed at Groove Toyota in Denver. Thanks to another guy on the forum that motivated me to bug Toyota.
     
  17. Sep 1, 2018 at 8:17 AM
    #77
    Steve89gt

    Steve89gt New Member

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    I think I read somewhere that it only takes a manufacturer something like 7 hours to build a trailer from the frame up; they’re really just thrown together. Makes me feel “awesome” about my investment in one...o_O
     
  18. Sep 3, 2018 at 9:38 AM
    #78
    JaxSmith

    JaxSmith New Member

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    I've been following this thread, and as a 2018 owner am very interested in the discussion about the harness change from 2017-2018. I'd like to look into getting a P3, but I'm concerned that I won't be able to find the right harness for it!
     
    Last edited: Oct 23, 2018
  19. Sep 3, 2018 at 4:20 PM
    #79
    Takemetoothemoon

    Takemetoothemoon New Member

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    Add another 2018 trd to the list, took my trailer out for the first time this weekend. Trailer kept “disconnecting” and then would reboot, a little scary going down a steep hill with no trailer breaks. Going to contact the dealership hopefully they know how to fix it.
     
    GoCboys likes this.
  20. Sep 4, 2018 at 5:18 AM
    #80
    sprtbkr

    sprtbkr Average Member

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    That second part number is missing a number. Can you repost it? Thanks!
     
  21. Sep 4, 2018 at 7:40 AM
    #81
    jtwags

    jtwags Concrete jungle

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    Have you noticed any heat issues with the load equalizer? About to purchase then and read somewhere, maybe Amazon review, that they can get hot but if wired up in series they stay much cooler if used while under constant load.
     
  22. Sep 4, 2018 at 3:54 PM
    #82
    BWinter

    BWinter New Member

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    The heat is a symptom of the load they are carrying. A 6 ohm resister will carry 2 amps at 12 volts. That would mean the load is dissipating 24 watts. If you put two in series it would cut the wattage to 12 watts per resister. Remember the resisters are used in parallel with the trailer brake magnets. The current in the resister circuit would be cut in half to 1 amp.

    I would respectfully consider higher wattage units. They may get warm but if you bolt them down to some metal it could act as a heat sink to dissipate the heat from the resister. Perhaps these would work. I don't know as I have never used them. Keeping in mind they would not carry this amount of current unless at "full braking" and not for very long.

    https://www.amazon.com/Resistors-Si...654&sr=8-4&keywords=turn+signal+load+resistor

    Merely a suggestion. Your truck your call.
     
  23. Sep 13, 2018 at 6:45 PM
    #83
    GoCboys

    GoCboys New Member

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    Just had this issue recently, kinda scary driving down the road with the RV and getting the message.
    Took it to dealer, supposedly they could not duplicate the issue (Um, no - not without the RV). Stated that there are “no known” issues. Basically told me the problem is with my RV. Grr!

    Referred to this forum and several other similar issues. They did offer to check with a Toyota Engineer visiting the dealership the following day. Called today saying that the engineer has not heard of IBC issues and change in production mid-year (BTW, mine is 10/17). Again tried to tell me it was the RV. Guess I will continue to try and convince them - or switch dealerships until resolved. :facepalm:
     
  24. Sep 17, 2018 at 4:13 PM
    #84
    BossHogg

    BossHogg New Member

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    Add another "Trailer Disconnected" warning to the list. I've got two trips to the dealership so far. After reading this thread I called ahead to the service manager at my dealership and explained the situation. At my first appointment they told me that they had ordered the wrong part. The second appointment the part was replaced but did not resolve the issue. I've got another message in with the service manager and opened a case with Toyota corporate.
     
  25. Sep 18, 2018 at 4:21 AM
    #85
    Volchek

    Volchek New Member

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    When I was looking to trade in my Taco on a Tundra I read about issues with the IBC. One thing I read was it was it being cause by a firmware bug. 2 different Toyota dealership service depts here in Atlanta confirmed this.

    I believe my Tundra was built in late April/early May of this year. Prior to picking it up from the dealership I made them apply all outstanding firmware updates. I've towed our trailer over 200 miles over 2 trips and the IBC has worked fine, no faults or issues.
     
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  26. Sep 18, 2018 at 7:11 AM
    #86
    BossHogg

    BossHogg New Member

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    @Volchek Thank you for the firmware insight. I'm going to check with the dealership to see if they did this.
     
  27. Sep 18, 2018 at 11:28 AM
    #87
    sbxx312

    sbxx312 New Member

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    Thanks for this. I pick up my 2018 SR5 tomorrow and after seeing your post, just called and asked the dealer to update the firmware.
     
  28. Sep 24, 2018 at 3:39 PM
    #88
    BossHogg

    BossHogg New Member

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    Just picked up my truck from the dealer and no more "Trailer Disconnected" warning. 3rd time is a charm! The paper work says they replaced the trailer brake switch and the brake control relay. I am super happy with the result and give the dealership on thumbs up on owning it.
     
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  29. Oct 9, 2018 at 6:14 PM
    #89
    RaycoJayco

    RaycoJayco New Member

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    And, yes, add another to the "Trailer Disconnected" list. I just upgraded from the 2017 4.6l to the 2018 5.7l for a better towing experience and as many of you reported, I'm also getting the Trailer Disconnected warning. What is really frustrating is that I saved my P3 from my 2017 and with the recent changes that Toyota made, there is no obvious way to install the P3. The new integrated brake controller only has control wires with no power or brake wires. What worked on my 2017 4.6l no longer works on the 2018. I have an appointment with the dealer next Monday but I expect they will try to blame the trailer and tell me nothing is wrong with it.

    Has anyone figured out how to install the P3 on the 2018 model? If there is a way to disable the error codes, I will hard wire it. Thanks in advance for any help.
     
  30. Oct 15, 2018 at 6:16 AM
    #90
    97_Toy_Tiger

    97_Toy_Tiger New Member

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    First post but have benefitted from this forum for a while. Typing this while sitting at the dealership for third time with the dreaded "trailer disconnected" issue. "Service Advisor" refuses to acknowledge information posted on this forum so I am waiting around until Southeastern Toyota "opens" so he can give them a call. I do not expect satisfactory results from this visit and will post the outcome either way.

    *UPDATE*
    After 3.5 hours, left dealership without resolution. Tech performed firmware update. "Service Advisor" says EBC was replaced with another and trailer was checked with another vehicle - same results, no issues. I left without saying a word and got the service managers appear-to-be-dissatisfied-customer follow-up call.

    How have you guys forced the dealership to replace the module when according to them, there are no issues. Irony of using quotations around "Service Advisor" are intentional. This is my 5th Toyota truck purchase and the only one I have actually regretted and for that reason, I cannot recommend Toyota of Greer in SC.
     
    Last edited: Oct 15, 2018

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