My 2015 Sierra Denali has what I thought was a dead battery. tonight in a driving rain storm. I had to get it jump started. When I got it jump started the service theft deterrent system light came on. I drove about 20 minutes, went into Autozone with the truck running and bought a new $200 battery and went back to my gig. When I came out the second time. Same thing happened, the truck wouldn’t start ( just clicks) ( both times I had the truck locked with the key fob and horn honked to set the alarm.)I had to have it jumped again. I. Drove 40 minutes home . In garage. I shut it off, and then Truck started up and the theft dt light went off. Weird. Battery might not be the issue after all?? Hopefully. I can return it.
