When you say you cant pull any codes did the scanner come on and communicate with the eng PCM ? Even if in the theft mode the scanner should still go into the PCM. Also you said it wont crank and I dont think the 2001 Neon theft could control the starter as I dont think the starter circuit was wired through the PCM on that year Neon. In the security theft mode it should still crank and start but then the eng will die right away. Did the scanner go into the PCM and read no codes or did the scanner not communicate with the PCM ? Ron