You can try this: Pull the ECU fuse, turn the key on several times to discharge any capacitors in the ECU. Wait about 5min. Put the ECU fuse back in, turn the key to on, and WAIT for about 15sec. THEN plug up your cable and initialize a file transfer. I got that once after trying to download a tune in a carwash entrance. Care moved out in front of me and I clicked "stop" since there were cars behind me and there was 0 progress made on downloading. A good 30min of cursing myself later, I tried the above. Worked. Make sure you give the ECU 5-10 sec to actually boot up before trying to connect to it btw.