06 only shifting in manual

[Tleesmith14]

Hello got an 06 1500 z71 5.3 roughly 175k on it.  All the sudden it will not shift out of first if I put it in the D position.  However if I place it into 1 I can then shift to 2 then 3 and so forth any ideas?

thanks 

[sefiroxx]

Once on 2nd, if you put it in D, will it shift up? If yes, 1-2 accumulator is shot. If not, oil pump may be failing requiring higher rpms to shift. Try a WOT test.

Also, if one of the engine sensors (ie tps), this could be giving bad data to the computer preventing it from calculating shift points.

[davester]

read codes from the tcm.  you need to use a more advanced code reader than the basic, cheap ones.  some parts stores will have one that will do the job, but I would suggest phoning ahead and checking...