[takpak]

We just had the "engine warning" light come on recently on our 2015 GMC. It's 4 years old with 28,000 miles on it. As to the first part about new and being filled, probably not. The dealership we bought from claimed to have filled it.....NOT. The dealership I use for service (very good one) had to fill it shortly after purchased, and it took almost 5 gallons. I recently got the recall notice on the tank sensor. Sure enough, not long after the warning came on. The dealer reset, and said try for a bit. A week later it was back. So, sensor was replaced under warranty. Now, one thing the service manager said, was to stay away from the Blue DEF. He said they've had a lot of trouble with store bought Blue DEF causing failures. Coincidentally, I had just had to put 2 gallons of Blue DEF in, as I was on the road and it was getting very low. Shortly after that, I had the warning activate. Coincidence, or???? GM uses a kind of "amber" colored DEF, and that's what they recommend. I will have to say that almost 4 years of dealer installed DEF, no problems. I put a bit of Blue DEF in, and the problem occurs. For me, I'll let the dealer fill it now. Then I know I have full warranty coverage!