Well I finally got my IAT sensor code cleared so i decided to drive the car around so the o2 sensors would be ready for my inspection test....well after about 30 min of driving around the check engine light comes on(of course) so i plug in my obd II scanner and now I am getting a P1870, Manufacturer controlled transmission. I never had this code before, about a week ago my tranny was leaking fluid so I had the gasket replaced. The mechanic put regular tranny fluid in, someone told me that GM cars require "special GM fluid"? Im not sure how much truth there is to that. Any idea what this could be? Or am i better off taking it to a shop?

Well, here's a link that may explain what happened.

It seems that different spec trans oils may alter the change/slippage characteristics of the trans.

http://www.actron.com/faq_detail.php?pid=16151&id=14

Someone here will come back with a more specific answer, I'm sure.

Alont