Jump to content

Recommended Posts

Posted

running a 2020 2500 Duramax LTZ dbl cab pulling a 20foot travel trailer.  Dealer setup TPM with no issues. We are on our first road trip, going to be out for 7 weeks and about 4000 miles.  Truck has 1700 miles and is a dream to travel with. Tried to check the TPM and am getting the message that there is no Trailer Connected. The trailer is connected, trailer lights are working, trailer brakes working. How to resolve?

Posted

Did you happen to hook the trailer up and plug in your 7 way connector when the truck was running?  The best way I have found is to shut off your vehicle when you are hooking up.  Hook up the trailer and chains before plugging in the seven way.  Ideally, plug the seven way in after the truck goes asleep.  Easiest way to tell the truck is asleep is if the light by the onstar symbol is out.  

 

I have also seen after you start the vehicle it may not recognize a trailer is attached until you depress the brake pedal.  

 

Hope one of these help you out.

 

#iworkforGM 

Posted

Hope you have the solution.  I did have the truck running when I hooked it up.  I just went out and unhooked the trailer wiring.  I will rehook in the morning before I start the truck.  I will follow-up tomorrow with the result.  Thank You very much for the quick response. Cheers

Posted

i have several trailers i hook/unhook too and i run into it saying i have no trailer hooked up right after i just hooked up the trailer...i just go to the trailer profiles and select my trailer and all my info is there

Posted

Does the trailer have LED lights? I read in another topic that sometimes there isn't enough load on the lights to sense the trailer. There is an adapter that one can purchase on Amazon. It plugs into the 7 way plus and then you plug your 7 way trailer into it. Puts electrical load on truck to see it there.

https://www.amazon.com/gp/aw/d/B00C4AYR3U?psc=1&ref=ppx_pop_mob_b_asin_title

 

On the plus side, you can run just the adapter without a trailer and when you turn on signals, if you have the 360 cameras- the truck will switch and display that side of truck's blind spot in the radio.

 

  • Like 1
  • 4 weeks later...
Posted

Just returned from a 4 week trip to Texas with the travel trailer and had numerous problems with "no trailer connected" issues.  Truck always recognized trailer connection, lights work, gain and tow mode restored, but often the "no trailer connected" when I check trailer for TPM. Doesn't matter if truck is off when plugging in the trailer. If I stop for fuel and unplug and replug, it might start working.  We do not have LEDs on the exterior trailer lights.  I will take the truck in for its first service once the pandemic passes and hopefully they can figure it out. Of course that will require dragging the trailer along and surely, it will work then. PIA. Also get numerous warnings about a failed blinker which if false of course.

  • 1 year later...
Posted

When I plug my 2019 GMC 1500 Sierra into my travel trailer it shows no signal to my rear facing furion camera on the trailer. I can put a jumper in my seven way plug on the trailer and make the camera show on my plug in monitor. As soon as I plug it into my truck with the lights on and truck running it shows no signal to my camera. My RV supplier told me mine was the third GMC/Chevy 2019/2020 trucks in the last two weeks with this problem. Glich is in the vehicles. What’s the problem. My trailer is presided for the furion camera.

  • 1 month later...
Posted

 The No Trailer Connected issue has gotten more complicated.  I have a car trailer with LED lights and have the same issue. The dealer has been really good about trying to resolve the issue.  They replaced the ECM under the spare tire and the 7 pin connector.  We have the same issue even with the new components. Plus it is now worse, the system loses its memory of the pairing to the TPMS. We just returned from a 8 day trip from Michigan and had multiple issues, had to stop by a Chevrolet dealer midpoint in the trip to relearn the TPMS which they did very promptly.  Local Dealer is working with Chevrolet to come up with a solution. 

 

Posted

Having an issue with mine lately.  Trailer will be fine, then driving along will pop up no trailer detected.  Just this morning, my lights were on and brakes were working, then halfway to where I was going everything quit working and message popped up no trailer detected.  I pulled over and unplugged the 7 way plug and plugged it back in, still would not work.  Luckily, was just a short trip with my 22 ft equipment trailer and some oak logs.  

 

My electronics seem to be having some gremlins, having other non trailer related screwy issues as well.  Another complaint for the dealer.  

  • 10 months later...
Posted (edited)

Has anyone found a fix for these gremlins? I’ve got 27,000 miles on my 2019 Silverado and the “no trailer connected” issue just started with a snowmobile trailer I’ve towed many thousands of miles and had no problem. It has LED lights and everything functions normally when connected to other vehicles. I have other trailers with both incandescent and LED lights and those trailers all work fine. 

Edited by Fast325it
Posted
On 8/8/2022 at 10:34 AM, Fast325it said:

Has anyone found a fix for these gremlins? I’ve got 27,000 miles on my 2019 Silverado and the “no trailer connected” issue just started with a snowmobile trailer I’ve towed many thousands of miles and had no problem. It has LED lights and everything functions normally when connected to other vehicles. I have other trailers with both incandescent and LED lights and those trailers all work fine. 

This is certainly not what we like to hear, Fast325it.  Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2019 Silverado. To do so, please send an email to [email protected] with ATTN: Fast325it/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s privacy policy, please visit https://www.gm.com/privacy-statement.html.
 
Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com
 

  • 4 months later...
Posted

2020 Sierra AT4, throwing no trailer detected, randomly. Lights not responding, no trailer brakes luckily it’s only a single axle, I have ruled out the wiring on the trailer. What can I do seems the truck has issues somewhere? 

  • 2 weeks later...
Posted
On 12/29/2022 at 6:07 PM, JakeJ said:

2020 Sierra AT4, throwing no trailer detected, randomly. Lights not responding, no trailer brakes luckily it’s only a single axle, I have ruled out the wiring on the trailer. What can I do seems the truck has issues somewhere? 

This is certainly not what we like to hear, JakeJ.  Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2020 GMC Sierra AT4. To do so, please send an email to [email protected] with ATTN: JakeJ/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s Privacy Policy, please visit https://www.gm.com/privacy-statement.html. The information you provide may be monitored and recorded and is subject to the GM Privacy Statement.
 
Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com
 

Posted

Just ran into same thing with trailer lights. 2013 suburban trailer lights work on 4 place snowmobile trailer. When I try it with my 2020 GMC 2500HD AT4 I get no trailer connected. Brake controller works but no trailer lights on trailer work. This is the first trailer I have had an issue with on the GMC. I purchased truck used in May 2021 and it just turned over 30,000 miles, 36 month warranty just ended in Sept. The dealer is going to try a new light module except it will take a week and I wanted to pull the snowmobile trailer this weekend. No quick fix. Going to try either putting in LED lights and or unplugging some of the marker lights to get trailer draw down to work some of the lights. 

Posted

Just ran into same thing with trailer lights. 2013 suburban trailer lights work on 4 place snowmobile trailer. When I try it with my 2020 GMC 2500HD AT4 I get no trailer connected. Brake controller works but no trailer lights on trailer work. This is the first trailer I have had an issue with on the GMC. I purchased truck used in May 2021 and it just turned over 30,000 miles, 36 month warranty just ended in Sept. The dealer is going to try a new light module except it will take a week and I wanted to pull the snowmobile trailer this weekend. No quick fix. Going to try either putting in LED lights and or unplugging some of the marker lights to get trailer draw down to work some of the lights. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.5k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,914
    Total Members
    8,960
    Most Online
    AidenVorpagel
    Newest Member
    AidenVorpagel
    Joined
  • Who's Online   1 Member, 0 Anonymous, 1,118 Guests (See full list)

  • Latest Articles

  • Posts

    • Thanks newdude!  By the time manual selection is needed, I'm probably too much of a control-freak to depend on the transmission sensing braking to activate automatic downshifting.  I would be anticipating the situation and already be manually downshifting.   This truck replaced a 2004.5 LLY diesel with the Allison 5-speed.  Putting it in T/H made noticeable differences (when the torque converter locked, upshift points, downshift behavior).  On this 2024 gasser with the 10L1000 I haven't been able to detect much, if any, difference.  Ok, I can never tell now when the torque converter locks up.  But I also don't notice differences in shifting.  For downhills, I've probably already manually downshifted by then anyway.  Since it's also more awkward (than the 2004.5) to engage/disengage I don't even bother.  Or maybe it doesn't really matter with just a 3k lb. camper in the bed?   Thanks also for the list of reasons the charging system might select various voltages.  However, what I am seeing doesn't fall into any of those categories.  It very definitely, and very consistently, rises after coasting/braking.  Maybe not immediately, but not very long after coasting/braking.  Very consistently drops voltage when no longer coasting/braking.  It might also be interacting with the camper battery charging (I might disconnect the camper and see if it changes the charging behavior).  I also need to recheck turning on headlights for when I want to force it to charge the camper.   Another JR, in June I converted the camper to LiFePO4.  Since it's not a good idea to try to charge lithiums directly using truck, I installed a Victron Orion XS DC-DC charger (which BTW is AMAZING!!).  Being cheap, I only had to buy that one item (besides the battery, of course) to do the conversion.  The camper OEM 120v battery charger (only 19 years old and works perfectly) and the truck feed the input to the DC-DC charger (not at the same time).  But I didn't want the camper charger feeding back to the truck so I kept the old separator.  I considered replacing the separator with a 30amp diode but that means more work and might add another 1/2 volt drop.  One thing that surprised me was the voltage drop over the long 10awg wire run, so I can only charge smoothly at 8 amps (because the DC-DC charger is completely configurable).  Another reason I don't want an added voltage drop with the diode.  I might also be a little lazy but all this work is being done under the sink with a small cabinet opening.    
    • apparently CA smog is (or at least was)  checking that the vehicle is using the oem and/or a ca smog approved tune, so I expect you'll fail inspection doing it.
    • yes, leaking exhaust will mess up o2 sensor readings, which in turn messes up fuel trims.
    • 286,740 Mile Services   8/6/2026   New AC Compressor. Refrigerant oil and dye, evacuate and charge system.  New exhaust system from cat back.  New Iridium plugs plus replace #3 coil Repair/rewire headlamp wiring (passenger side) and replace all forward bulbs. Polish lenses of both assemblies.  Pull rear rotors, clean and adjust parking assembly. Inspect, clean and grease front calipers. Check pads and shoes.  4 wheel power bleed of brake system. Dot 4 Reset idle speed 50 rpm higher New Serpentine belt.    Will need new pads in the rear in about 5K more miles.    Tax Title and License out the door just short of a grand.    AC clutch had bitten the dust. 1 year warranty on the pick and save replacement. Thing will make a Polar Bear cry Uncle.  He spent quite some time on the wiring. It was in the harness and he does nothing half. I got off cheap. I have considerable more light down the road. Sylvania Silver Star replacements.  Gas seal between the porcelain and shell of plug #3 was blown, cooked the coil. That was the cold miss.  Love the new exhaust. I can sneak into the neighborhood again.  Nice to have a working parking brake again. Belle Tire never got it done. That was disappointing.    This was one of her bigger bills and still way cheaper than a payment even given the oil consumption. This thing cost me under a hundred a month in repairs and normal routine costs. What is my incentive to replace it? 🤔           
    • hello I recently bought a 2012 gmc 1500 with a 5.3 and have a AFM disabler on it I'm interested in doing a cam but I'm worried if I remove the AFM system I will fail smog does anyone have info if they are able to detect that or a work around to it (not talking about hot smogging) please let me know thank you  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...