I am working on a 2005 Kodiac 4500. We are trying to correct the speedometer for tires that measure 41.25 from the top of the tire to the ground. In the engine tune we can change H0101, but it does not correct the speedometer. So next we went into the TCM and we see H0101speed sensor pulses per mile, H0103 final drive ratio, H0104 trans output shaft revs/mile, H0136 tire revolutions per mile. I matched up H0101 in the TCM to the same number in the ECM (100328 ). Next I changed the H0103 from 4.10 to the actual 5.13. (We tried it both with 4.10 and the 5.13.) Then I try to change the H0104 to what the calculator tells me it should be (2508 ). I can put the number in but every time I arrow down to the next box or try to save it will automatically change the value back to 1024. I tried the calculator Apply and everything else I could think of. When we drive the truck with what does save it will not shift out of first.

We could not correct the speedometer with engine tune changes alone.

Thanks for your ideas.

Mark