I have a 2004 avalanche 1500 5.3. Sometimes the trans works fine, then i stop, engine off. then start an it acts weird. It seems like it only has 2an 3 forward an it wont downshift or upshift on its own.The fluid an filter are fresh an the trans is a M30 deep dish 4L60 , with 60,000. The codes are PO740,PO753,Po758,PO785,P2761. I sure could use some help. thanks P.S. I hope i am in the right section