2023 Chevy 2500 Trailer Lights not working

[Cjdalbey]

Lights work fine when i pull my horse trailer with my 2015 Chevy 2500.  Bought $15 Curt 7 pin plug tester and it works fine with my 2015 Chevy 2500.  Horse trailer lights and the 7 pin tester do not work with my new 2023 Chevy 2500.  Dealer is telling me "some trailers with LED lights do not draw enough current for trailer lighting to operate properly" and suggests I add "load resistors" to all my trailers that have LED lights.  See page 2/6 of the attachment below. He said my 2023 Chevy 2500 trailer plug passes all the tests on their $8k machine and there is no problem with my new truck and the problem must be with my horse trailer lights and the Curt 7 pin tester.  I disagree since the horse trailer lights and Curt 7 pin tester works with my 2015 Chevy 2500.  Most all newer trailers have led lights and the lights should work with a brand new truck designed to pull trailers.  Anyone experiencing the same thing?

trailer light issue with 2023 silverado - page 1-2.pdf

Edited March 2, 2023 by Cjdalbey
correcting

[Jsdirt]

That's horseshit. The dealer is LYING. I've run a Dively flatbed with LED lights from the factory since 2009 with my 2007 Silverado. There's always the possibility that GM screwed with the system and made it suck on the newer models, but I can't see any logical reason why low-current LEDs would cause zero output from the trailer plug.

 

Sounds like yet another GM dealer attempt at weaseling out of the warranty. If they won't fix it, take it to another dealer that will, or call GM corporate and tell them you are NOT happy.

[64BAwagon]

The dealer is correct, the module requires a certain amount of resistance from the trailer in order to enable the trailer circuits on the truck. Its been a common issue with the newer, more electronically sophisticated trucks. I believe GM just issued a bulletin about it but I cant recall for sure what the fix was, it may have been a new style module but dont quote me. 

[Jsdirt]

GM screwed up the system. Shocker, lol. Not surprised one bit!

 

Thanks for the info.

[64BAwagon]

The problem is partly due to the fact that most trucks use modern electronics to enable all the sophisticated stuff to work. While trailers are typically wired the same way they were 40 yrs ago. Its like linking an abacas to your PC. The engineers dropped the ball on not recognizing this would be an issue.  

 

The 2007 truck has an entirely different electrical architecture vs the newer trucks. 

Edited March 3, 2023 by 64BAwagon

[Jsdirt]

Yep, well aware of that. 

 

Like I always say, electronics are great for desktop computers and smartphones. They have no business in an automobile, IMHO. Part of the reason I just quit the auto industry for good just 3 weeks ago. Sick of the infuriating engineering, endless costs for tooling and constant updates, rust from the shitty, low-bidder chinese metals they use, and complexity that makes pattern failures a thing of the past when it comes to vehicle electronics. 

 

I was mostly working on '04-'18 as of late - I can only imagine what demons are in store for the '22-up models. Glad I'm not a new young tech starting out with this bullshit. Took on a new job as a maintenance tech for a giant corporation in the city. Never been so happy to go to work in my life, lol.

[2023GMCSierra]

I have the same issue with our 2023 GMC Sierra 2500HD. We had a 2018 Chevy LTZ and our 2020 trailers worked just fine but now with the new 2023 GMC,our trailer lights don't work.  

 

Does anyone have a recommendation on what load resister to purchase?

[Gene Souza]

...

Edited June 20, 2023 by Gene Souza
new post

[Gene Souza]

I have the same issue.  I have a 2016 Chevy 2500 HD and 2023 Trailer with all LED lights.  No issue.  Just picked up a 2023 Chevy 2500 HD and the trailer lights don't work.  Dealer says nothing wrong with the truck.  Very frustrating as my 2016 is in WV, my trailer is in KS, and I live in OR.  Can't find the adapter to get my new truck and trailer home.  Looks like GM and Chevy have known about this since 2020 and have done NOTHING about it.

[64BAwagon]

I have heard (but have no documented proof) that sometimes wiring a resistor in the parking lamp circuit on the trailer will help to wake the module up on the truck. 

My 2024 when hooked up to my Reflection 337RLS (my 2021 did not have the trailering app and the 2024 is an entirely different electrical architecture) shows the left and right brake light error message although all of the lamps function properly. Since the trailer is entirely LED the truck sees very little resistance and shows an error even though the system still functions. I have some resistors on hand and I may wire one across the connection for the park lamps at the umbilical connection on the trailer. This would create a little resistance and hopefully satisfy the truck. 

I am told that the trailer MUST have a good ground and any minor wiring issues will cause faults. 

Keep in mind that the dealers have access to technical help on this issue but many dont want to spend the effort because it doesnt pay any repair time to solve the issue. 

Edited June 20, 2023 by 64BAwagon

[Dabney]

I'm the one that originally posted this.  I originally said my 2015 duramax works fine with my trailer with LED lights but my 2023 duramax does not.  I had my local mom/pop shop look at my trailer and make sure all the grounds were solid.  They said they found one that was a little loose and fixed it.  Since then, my trailer is working fine with my 2023 Duramax with no adapters.  My conclusion is that the design of the older truck was just more forgiving for a not so perfect ground, and the newer trucks need the ground to be perfect.  (hopefully that makes sense).

[Jsdirt]

Par for the course. From what I saw over my 14 years turning wrenches, the newer the vehicle (REGARDLESS of brand), the more corners were cut at the factory. Everything is cheaply made, yet the engineering is overly complicated. A recipe for constant problems. Wiring gets thinner, copper content goes down / less quality, so what would've been a non-issue just a few years ago, becomes an issue.

 

I can't wait to see how this new crop is holding up in 10 years ... 

[emptech]

From what I've read, the newer "smart" vehicles "test" the trailer lamps.  They want the trailer lights to draw at least 80 milliamps.  At 12 volts, thats about 200 ohms.  I have the same problem, what worked on my 2009 Suburban will not work on my 2024.  I'm going to add some 180 ohm resisters across the LED lights to see if it makes a difference.  There is probably a relay under the hood that supplies power to the trailer circuits, IF it thinks you have a trailer.  If I knew which relay it is, I'd try bypassing it.   Jim   [email protected]