zmnypit

I'm still fighting this issue. Today was 73* and dash display was saying -6*. Not sure what else to do other than take it to the dealership.

So for the last two months I have been all over this forum, Duramax forum as well as Google searching for an answer for the service trailer brake error on my 15 Sierra 2500 Denali. I have a 2017 24' all led tilt trailer that was purchased new and its never worked on my truck. I also get the service trailer brake system with no brakes or lights when I use it. When I hook it up to my buddies 09 Duramax all lights, brakes etc work fine. 2nd trailer is a 2010 18" car trailer, non led, with brakes. When I pull it I get "check trailer wiring" then shortly after get the "service trailer brake system" I've replaced both plugs with the Pollack plug with same result. Traced and re traced both truck and trailer wiring with no luck. Added grounds, wiggled the connector, cleaned all the contacts etc, nothing seemed to work. While sitting there this afternoon I took a flat headscrew driver and bent each pin outward a fuz until it was really tight when plugged in and just like all the lights and brakes work with no issues on both trailers. Two months of researching and It was so simple. I'm posting this for the next person that comes along with the same issue. I never saw anyone mention adjusting the prongs of the truck connector so hopefully this helps someone.

PM or email me. [email protected] Thanks!

If you're referring to the intellibeam thats correct, it doesn't work with this conversion as its PCM controlled. Just the adapters needed is all I carry. I used to have the lights as well but the cost is too high to sit on them.

No worries. Yep you don't have them

located in central Alabama.

Just removed the factory summit white wheel well moldings and replaced with the standard black mouldings. Looking to sell as I have no use for them. It's dark now so in the morning once I get them cleaned up I will get detailed pics of all of them. I do know the passenger rear has a small area where it meets the bed that appears to have chipped or been hit with something. $100 plus shipping located in central Alabama.

I put 35x12.50 MT's on my factory 20" wheels with 7 turns on the stock keys and shock extenders with no rubbing and no issues.

Thanks! Im working with a guy right now that converted his Silverado 2500 front end to Denali 2500 front end using the 1500 lights. He replaced all the wiring from the fuse box to the lights etc and the DRL isnt working. He texted me last week the dealer could possibly reflash the BCM with a sierra calibration and they may possibly work but I havent hear back yet. If interested his Instagram is dmaxbjay

PM me

Is the dash display still reading correctly now? Im too in Alabama and my 15 2500 denali will read normal for a min then once driving it will count down to around 25-35*. I've replaced both the mirror sensor and the sensor behind the grill with same result. Like you said its mid 90s here and the dash display will say "ice conditions drive with care" lol. I've yet to figure it out and the dealer told me the same thing, just drive it for 5-10min. Mine seems to be opposite, you drive it and the temp goes down and the AC gets confused.

FWIW this is the 2500 section. Theres a thread in the 1500 section as the vibration is known issue with 1500's. No one know the cause but several have claimed to remedy it. https://www.gm-trucks.com/forums/topic/153186-shake-or-vibration-issues/?page=802

May need a capacitor on the low beams. Does the high beams still work when they lights are not working?

So I need to have it re calibrated?

Nope. Drove maybe 30min today on lunch and temp would never get about 62* on the dash while its 97* outside.