The ELM 323 and 327 (ELM 5) support the GM enhanced, you just need to write the software in a way that it can retrieve the parameters. Of course, I can't guarantee anything until I try it.
ELM, Automotive Tools, Car & Truck Parts & Accessories, All matching items for sale.
They dropped in price, you can Buy It Now for under $25 and bid for under $20. But realize these are knock off's of the good quality ELM scanners, but who knows.....