I'm probably wrong in what I think, It's just my idea, but I would try and see if manually selecting a Chevrolet Silverado might be a workaround,, if not try to get a hold an old DS708, or a Snap On scanner for the old car models . I seem to remember my old DS708 worked better on those old cars than my Maxi Sys Elite . When New model software first releases ( most cars are still under new warranty at dealer) I think software version will work as good as it ever will , then after a few years OE copyright challenges creates layer upon layer of system software optimizations listed as accommodating some new feature or adding a new language or other fluff ,and naturally some things get tweaked in order to avoid OE copyright infringement lawsuits, and over time some of the work around tweaks work ok, and some don't always work , and the software of older vehicles eventually gets compromised from all the optimizing, and either gets removed or has to be licensed for use if a suitable software workaround can't be found by a certain date . The older the vehicles get, the unresolved software challenges gradually move through the courts and because more and more OE companies build cars in China now there's more legal pressure that cause Optimizing updates to be more common than before, it's kind of a fine juggling act on a tightrope . things, break , have to disappear, fixed , then reappear later, who knows , but it's got to be frustrating challenge to be a software engineer if something is working just fine as is and suddenly some bureaucrat says to change it to satisfy another bureaucrat.