When connecting our ECMLink cable to the laptop, the FTDI driver used by our cable wants to assign different COM ports to each cable. This is not practical for a laptop used by a shop or general tuner when connecting cables from multiple customer cars. To correct this, you can tell the FTDI driver to use a fixed COM port for the USB port you plan to use. This will force the driver to always use COM3 for one of your USB ports, for example, regardless of whose ECMLink cable you connect to that port.

To tell the FTDI driver to always assign the same COM port to a physical USB port, you have to edit the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\FTDIBUS\Parameters\LocIds

In this key, you will specify the location IDs of those two USB ports. To obtain the location IDs of those two ports, you will use the USBView application provided on the ECMTuning installation CD. Go into the USBView directory and run the usbview.exe application. You will be presented with a screen as shown below. Of course, the PC on which you are running this application will have a different configuration.