problems w/ 2001 chevy 25hd *Allison trans. HELP

problems w/ 2001 chevy 25hd *Allison trans. HELP
http://cdn5.tribalfusion.com/media/37536.gif (http://a.tribalfusion.com/l.click?clickID=ITCMPKGKDKMLEMNWKLGGNRPUPUEYRQIHRJ NLSOIOVIEMLGLOLDPCLBKQNXCURLPGSRCINP&clickURL=http%3a%2f%2fa%2etribalfusion%2ecom)i HAVE a 2001 chey 25hd crewcab
It has 71000 miles, and just recently began leaking what looks like transmission fluid, It was not shift gears when driving either, and MY
Reduced engine power light and check engine power light are lit.

Please help what could be the problem.
Any suggestions would be great.....
Thanks

Have you checked the Transmission fluid and taken care of the leak? The computer is probably detuning the engine to keep from frying the tranny.