I have a 2008 3500 with a standard transmission. I changed the wheels and tires to 35 1250 20. I went to the dealer to have the computer adjusted for tire size and to have the fast idle enabled and the said that they can not find any PTO setting or fast idle, they also said that they can not adjust the program to allow for a tire that big. Anybody know what i should tell them to look for.

 

Take a look at this thread

https://www.dieseltruckresource.com/...nual+high+idle


I dont think you can adjust to that large of tires with the starscan. You may have to find some other means of doing it.

 

Thanks Blake I did ground the little green wire but it still does not work do you think now that i have it grounded that the dealer will see this on there programer

 

Once that wire is grounded they should be able to activte it. It's just a simple walk around of the clutch bypass switch.