Traction Control and Loss of power

I've owned this Impala for a few years, and it's
been very faithful. Recently it started activating
the TCS at low RPM, on any surface, and lost all
power in 3rd. No lights on in the dash, except
when the TCS kicks on. It does have a long shift
code in the trans that isn't lighting up the dash,
but to fix it I've been told I have to replace the valve
body. I do know the 2005 model is notorious for
transmission problems, I'm just hoping there is a
fix without ripping my front end all to pieces.