2006 3500 4x4 auto Big Horn Edition. MIL light stayed turned on after the diesel started. I tried to cycle the key to get a code, but failed to get anything. The truck has 2700 miles on it and the dealers are all closed until Monday. Any thoughts? Thanks cdru.

 

Some say you can and some say you can't get the codes on a 2006. In any case did you cycle the key:
on/off/on/off/on and leave it on?

You might also try an Autozone or the like. They will read codes for free.

Anything change recently that would cause a code?

 

Yes, I cycled the key and left it on for a short time. How long should it be left on? I did add an aftermarket alarm system about a month ago that reads a voltage drop when doors are opened and the interior lights come on. Yesterday when I was washing the truck and under the wheel wells, the alarm kept going on and off by itself. I must have gotten some water on it. Don't know it that would cause a problem. The alarm is wired directly to the first battery with a fuse. cdru

 

after reading more sites, I realized that I had to cycle the key "quickly". The code system worked, but it shows no codes, just "........" and then "done". What ever is causing the light to be on is not showing anything on the code system. Any ideas? cdru

 

Some codes won't be shown by the key trick. You'll have to get them read by a scanner.

Just to confirm....does the light that is illuminated look like an engine?

 

Yes, it does look like an engine. In the owners manual it is referred to as the "Malfunction Indicater Light". cdru