When I reached 20000 miles on my truck, took it in to dealership and they did an oil change and there was a computer update at that time. After they updated computer, I started having problems with the engine. The engine fan would constantly come on and the engine would get hot. I noticed it more when I was pulling a cargo trailer. I recently bought a pontoon boat and it does the same thing with it. Now, the engine fan comes on if I'm pulling or not. Took it into dealership last Wednesday because the engine fan came on after the temperature was over 240 and temperature kept rising and the engine overheated and the red lights came on and after a few seconds, the lights went off but the engine fan continued to stay on. Normally when you stopped at a stop light or sign, the motor would come to a stop. It stays on all the time now. It seems like no one knows how to work on these trucks. What do you do? Who do you take it to? I need help. This is my second eco diesel. The first one was perfect!