I know now my '90 DeVille is "coasting down" properly when that "70 mpg" appears (mine currentl doesn't). I also know I need to adjust the voltage to the TPS by overriding the ISC exrension/retraction.
Question: I know how to get into diagnostics to check codes, but what buttons do I push to get to E.5.3, which is the ISC override function?
Thanks, all!!!