i have a 05 chevy avalanche yesterday i started my truck and the check engine light came on no 2nd gear all i have is first and third . codes are po758,po740,po753,po785,p26761 i heard about a ignition switch issue need help please

 

We are having the same problem with our 04 Avalanche . . . no second gear and no overdrive. Have heard about the ignition switch problem but didn't seem like it could affect the shifting ? ? ?