No trailer attached but still getting trailer light errors

[gemarsh]

2022 GMC 1500 AT4 x I had the same issues above, tried fuses and even a new trailer control module, nothing worked until I took apart the wiring harness going into the trailer control module and found a shorted and corroded wire. The copper had disintegrated. Spiced and used waterproof butt connectors and now working again without error. View attachment 26271

Welcome.

Good find!

 

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[Eighty4]

Hey fellas. Just had this happen to me. Hooked up a utility trailer (3 years old) to my 2024 AT4 and a couple of miles down the road started getting the check left trailer light wiring. Disconnected and dropped the trailer where I'm going to need it tomorrow but now my truck still thinks the trailer is hooked up and giving me trailer light warnings along with the double time blinkers and trailer turning cameras. All of the lights were working fine on the trailer when it was connected. Checked all of the fuses that were mentioned above plus a few more and they're all good. I pulled a bass boat almost 2000 miles last summer and never an issue. Truck is still under warranty. Is it time to make an appointment with the shop?

 

[gemarsh]

Hey fellas. Just had this happen to me. Hooked up a utility trailer (3 years old) to my 2024 AT4 and a couple of miles down the road started getting the check left trailer light wiring. Disconnected and dropped the trailer where I'm going to need it tomorrow but now my truck still thinks the trailer is hooked up and giving me trailer light warnings along with the double time blinkers and trailer turning cameras. All of the lights were working fine on the trailer when it was connected. Checked all of the fuses that were mentioned above plus a few more and they're all good. I pulled a bass boat almost 2000 miles last summer and never an issue. Truck is still under warranty. Is it time to make an appointment with the shop?

Welcome.

 

[Eighty4]

Update: Was ready to try the battery disconnect this morning if my truck was still stuck in the stupid trailer light warning mode but it was fine. Evidently it cleared itself with enough power down hours overnight. Hooked up to the same utility trailer that caused the warnings yesterday and no problems towing it for a couple of hours. Yesterdays hookup was in the rain which may have caused a questionable connection on the trailer but who knows?

 

[pinebaron]

Update: Was ready to try the battery disconnect this morning if my truck was still stuck in the stupid trailer light warning mode but it was fine. Evidently it cleared itself with enough power down hours overnight. Hooked up to the same utility trailer that caused the warnings yesterday and no problems towing it for a couple of hours. Yesterdays hookup was in the rain which may have caused a questionable connection on the trailer but who knows?

 

[Ejays]

Update: Was ready to try the battery disconnect this morning if my truck was still stuck in the stupid trailer light warning mode but it was fine. Evidently it cleared itself with enough power down hours overnight. Hooked up to the same utility trailer that caused the warnings yesterday and no problems towing it for a couple of hours. Yesterdays hookup was in the rain which may have caused a questionable connection on the trailer but who knows?

Glad it worked out. The other thing I have noticed is do not have the truck running when you connect. I had minor issues when I first got mine and connected with the truck running.