Autofix range of what? The max/min value used to make the graph? The max/min value displayed on the graph? The "width" or number of records represented by each bar?
You will likely have better luck with Proc SGplot or SGPanel and that histogram plot than Proc Univariate. The graphs in Univariate are intended for data exploration and do not have all the options for controlling appearance.
You might get univariate to come closer to what you want by restructuring your data so that you have a single variable with values and make your current variable name another value to use on a BY statement. Maybe. Your data just may not allow univariate to behave as you want.