When you have the data PID that you're interested in, touch the drop down arrow to the parameter name and then select the waveform function. Once you see the waveform, there will be a button saying 'Set Y'. Press this and it will bring up a min and max range window where  you can enter values in. When you touch the text field for 'min' example, a virtual keyboard will pop up for you to enter the value. Same holds true for the 'max' value. Then click on Set or OK. If the virtual keyboard doesn't disappear after entering the values, look down at the bottom of the screen and in the lower left corner, click on the 'down arrow'. I just went out to a car and hooked up the MaxiSys Elite to be sure that it worked and it was fine. Although the MaxiSys Elite comes with a hard copy manual (version 1.0), there is an updated version, (version 2.0) on the website here in a PDF format. This information can be found on pages 44-49 which includes setting min and max points when recording data. Hope that helps!