Well, that surprised me. The TS and GR are definitely stored in your "customized" tune file. This leaves only ONE possibility, you are not loading them into the PCM.
So, do it again, for whatever tune you want to use. Scroll to "Load Previous Settings". Check the TS and GR if you'd like, hitting [Enter] after viewing each setting, then scroll to "Done" and hit [Enter]. At this point, you should see the usual progress display telling you that the PCM is being programmed. At the end of this, there should be a "click" under the dash and a "programming complete" message (as I recall).
A TS of 2905 should make your Gryphon and dash speedo read MUCH faster than the GPS. I would think that would show a +9 mph error at a true speed of 70.
And, if you've followed my directions exactly and still have the same problem, I'm out of ideas - except
what year is your truck? I've been working on the assumption it is an 04-08 model. Is it possibly a pre 99 model? If so, you cannot adjust the speed with a programmer. You will need to change the VSS on the rear axle if you mount non OEM tires. Edit: Nevermind - I see from your
User Profile that you have a 2007 truck.
- Jack