My check engine and emissions light came on at the end of December. My first mistake was to take it to an AutoNation Chevrolet dealership. The Duramax had just under 50,000 miles and is covered under their powertrain warranty. They were nice and told me to drive on the highway for 30 minutes to re-generate the exhaust filter, so I drive and the lights don't go off. Then I bring it back to the dealership so that they can run diagnostics on it. I wait a couple of days for the part to come in and then drop off my truck. It was supposed to be a 3 hour fix to replace the DEF heater pump. Seven plus hours later they give me my truck and inform me that they replaced the pump but can not get the check engine and emissions light off. Once these lights are on, the computer warns you that after so many miles, it will start to power the truck down till it is inoperable. I complain to General Motors and they inform me to take it to another dealer. After I make arrangements for transportation, I take it to another Chevrolet dealer. One that at least sells diesel pickups. They had the truck for 5 days. They were awesome. They didn't charge me anything and explained the work that they did. They uninstalled the DEF pump and re-installed it correctly. Then they drove it for around 100 miles which I agreed to. Everything was good for a week until I tried to go to Tennessee from Orlando. In Georgia, the check engine and emissions lights come on again and the truck starts to power down by reducing your speed. I again call General Motors and they are a little more helpful. I take it to another Chevrolet dealer in South Georgia. Those guys were amazing. They immediately took my 2016 DuraMax in and started working on it. They had to pick up another DEF heater pump from another dealership. These guys stayed late just to try to get my truck back on the road. I can't tell you how much I appreciated the effort. Unfortunately, 20 miles up the interstate, the check engine and emissions light come back on, and the truck starts it's procedure for reducing speed and powering down the truck. I turn around and head back and get a hotel room. I am back at the dealership bright and early. I spend 13 1/2 hours at this dealership in 2 days. There diesel technician was incredible. He was one of those guys that just wouldn't give up. He found a shorted wire that seem to be the cure. I finally leave only to head back to Florida. Let's just say that the truck is parked and isn't moving until I can get serious direction from GM. Taking it to a 4th dealer in as many weeks isn't acceptable. GM makes such a great truck in the DuraMax. This is my second one but I can't stand these DEF issues. What rights do consumers have in a situation like this.