I bought a 13 GMC Sierra 1500 a few months ago, love the truck. Pulling out of the dealer the service stabilitrak and traction control light came on. Turn around and they fix it, said it was a bad switch. Barely a 150 miles later its back on, they replace the switch again. Same thing, couple hundred miles later the light is back on, take it to a different dealer, they replace body roll module. 50 miles later the light is back on. This time I file "final attempt to repair" with GM under the lemon law. They instruct me to take it back to the dealer I purchased it from for repair. They say there is a TSB about a connector, they replace it.
So its been a couple weeks and around 500 miles, the light hasn't come back on but I have this feeling deep in my gut that it wasn't repaired, they just manipulated it some how to keep it off. Something with the truck doesn't feel right, I don't know how to explain it. I've learned to listen to these gut feelings because I never get them but when I do they're usually dead on. I've said nothing to my wife about this and kept it to myself.
That brings me to today. My wife drives the truck probably more than I do, she called today and said the "grade braking" light came on. I ask her if she had it on tow mode by accident and she said no. I asked if she was going down a hill when it came on and she said no, it was the road we live off of which is pretty flat. She then went on to tell me that she had a feeling something with the truck just isn't right but she couldn't tell you what, it was just a feeling. So we both feel that way.
So, is there a way to manipulate the light to stay off and whatever the real problem is is starting to show?
The stabilitrac light and some other warning came on in my 2007 Tahoe a while back. After some internet searching I found the cause would be either a bad sensor or the transfer case was shot. I also found that you could turn the key off and on about 10 times and the light would go off and stay off for about 50 miles. Of course I did the logical thing and traded it in.
The dealership can most likely plug a computer in and shut off any options they want. They probably shut it off all together. I would just keep taking it back to the dealership to they either fix it right or give you a new truck. Its a shame how a lot of these dealerships always try to "band aid" fix problems while its under warranty.
If the light is not coming back on then its probably fixed. I don't know what to say about the "grade braking" its my understanding that the feature is passive, maybe she was coasting for long enough to trigger the feature IDK. I highly doubt any dealer would sabotage or disable the system, especially considering the safety factor in doing so. There would be a tremendous safety and liability issue involved if they did something like that. The fact that it took a few visits to fix was probably because the factory (GM) finally recognized the known issue and came out with a TSB for the correct repair. Not that this is your fault but when you go to different dealers for the same problem it kind of makes it a new problem, meaning that if you returned to the same one they might be more aware of the repair history and went to step 2 on the repair instead of starting over like the other dealer probably had to do.
The thing about dealers is they can fix the problem but sometimes the problems need to addressed at the factory level. That's why you have things like recalls, TSB's, updated or revised parts, software calibrations etc. With every new model there comes new problems, bugs, software issues and so on. On top of all that normal parts can fail, normal systems might have glitches, assembly line errors, its goes on an on.