Speed adjustment

[Rawze]

This leads to an even bigger question ...

If the rear axle ratio is incorrect in the truck, you need to find out why.

Did someone physically change the rear axles out with a different ratio at some point?. - The data plate on the truck should show the correct rear axle ratio that was in it back when the truck was new.

Or did some complete idiot copy the program from another truck into yours at some point, attempting to delete it or for some other reason, and you just now noticed that some of the data does not match up?. -= Copying programs off one truck to another is a no-no that leads to efficiency losses, incorrect cylinder balancing, etc. even if the hardware is exactly the same. This is because the ecm only does some of this type of stuffs to match itself up with the engine right after a clean, factory program is installed, and does not bother to do it again after that.


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and yeah .. setting the rear axle ratio and the tire size adjustment as well is how you make it match up.