I tried using my GM OBD II Enhanced tool but almost all of the parameters fell out of the list after I connected to the vehicle. Why arent they supported?
The exact vehicle that you are trying to connect to with GM OBD II Enhanced tool must be vehicle selected when you try to connect the software. Check the VIN of the vehicle you are trying to read data from and select the appropriate vehicle (year, make, model, and engine size) from the Select New Vehicle screen. If the incorrect vehicle is selected, all but the generic parameters will fall out of the list. When the correct vehicle is selected, the parameters stay in the list. The vehicle does not support the way the scan tool requests the information. If you have Professional version 1.0.7.62 or later, or Personal version 1.0.7.65, then under the Options menu on the parameter grid screen, select Fast Data Packets so that the check box is no longer on and then reset the tool. The parameters should now stay in the list.