I started to have these warning lights come on in my truck on a regular basis. For some background my truck has 6400k and is used for driver training so the park brake gets used 50 to 75 times a day. Although the warning lights could be cleared by cycling the ignition for a quick fix the problem remained. After 4 trips to the shop and the dealership replacing the Steering Control Module which requires the pulling of the steering column and a wheel alignment, part of a wiring harness along side of the park brake was found to be worn through. The wiring harness was re-routed and appears to have fixed the problem. I see there has been the occasional post in this regard. I have attached a copy of the work order relating the work done.
I have had that same message and the Service Towing (Trailering?) System at intermittent times as well. Always at startup where I crank her up and it stops cold. I then turn the key again and it starts normally and one of these 2 messages appear. Hasn't happened enough to force me in for warranty work. Thinking these codes don't stick around and if Chevy can't dupe them then why bother?