I've recently bought a 95 GMC Yukon with a BJYL PCM $0D bin and I've been doing a bit of driving and data logging.
One of the annoying charaterristics the truck has is to hold onto 4th gear as I moderatly accelerate from 40 MPH to 60 MPH up an onramp. The engine is lugging and goes better if I manually change from "D" to "3" as it goes up the onramp, is there something I can change in TunerPro that will make the trans downshift from 4th to 3rd sooner as the MAP and throttle position go up?