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Random “Service Trailer Brake System” warning?

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On 3/23/2023 at 12:20 PM, wildfan said:

I have similar issues with my 2019 LT. Every time I start the truck this past week, with no trailer attached, I get the "service trailer brake system" message. I can dismiss the message and it does not come back during the current drive cycle. If I turn off the vehicle and restart it, the message reappears.  Nothing has been touched or modified from OE. I'm curious if there has been a common repair related to this situation. I talked to the parts counter at a GM dealer, and he indicated they have been replacing a lot of controllers as of late, but didn't know the owner's complaint. Since you can buy a new OE controller for around $10, I'm tempted to throw one in and see what happens prior to paying for diagnostics at the dealer. 

I'd love to know if you find out what caused this? My 2020 Sierra just started the same messages. I'm getting 3 different ones. "Check right trailer turn signal lamp", "Check left turn signal lamp" & "Check trailer brake light".  Truck is stock and I've not had a trailer hooked up for 4 months. 

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