I have a 2011 LML which I purchased used last year. The truck currently has 55,000 miles on it. Since owning it, I have had 3 separate issues with the glow plugs. I will get a CEL with the Code "Cylinder X Glow Plug Control Circuit" (X representing whatever cylinder it is). I have had issues with the #8 and #7 glow plug and today I got a code for the #6 one. Looking back at the GM Service Records for my truck, it appears as if the previous owner also had a number of issues with the glow plugs, the first being reported when the truck only had 1,000 miles on it! Every time there is a problem, the dealer just throws glow plugs in it and gives it back. According to the service records, the GP Controller was replaced at one point before I owned the truck. My major concern (aside from it being an inconvenience to keep going back to the dealer) is that my Powertrain Warranty is up in January and what is going to happen when I get stuck footing the bill for this every few months? Is this a known problem with the LML motors? Are there any TSBs out there regarding it? Is it worth my time to try and contact GM and above the dealer level and see if they will do anything? Thanks for the info!