Help Help Help transmision porblem

Hallo Group

I have 2001 Chevy Tahoe LT 4X4 actualy i have two of them,
one feels it has no 1st gear not too pwerfull,and no overdrive i cant spped up more than 100 miles rpm hits 3000 as if i have it on low gear,i do have check engine light on i scanned it
and its transmision code,i was told its transmision module electric part,the question is i do not wana rebuilt the whole transmision if its an electric part only,or should i rebuilt it all,it shifts smooth,can u plz help
thanks

Fred

The shift solenoids can be changed w/out removing the transmission or even the valve body, so if you feel you don't need a complete rebuild at this time, then save yourself some cash and just change the defective part.