I recently bought a 2011 siverado 1500 LTZ and have put around 10K miles on it. I have had an issue with the 4x4 not working.the dealership reprogrammed the transmission and so far the 4x4 hasn't acyed up. I also haven't had to use it. I also had a probel with my speeedometer not working along with turn sighnals, gear indicator, and mileage read out.They couldn't replicate the speedometer issue and told me that sometime connection is lost around the fuse box . Has anyone had an issue like this?