5d mk iii is shooting under exposed.

[SPell]

Are there fixes that I can do without sending it in to Canon? 

[jrhoffman75]

What shooting conditions?

Reset all camera settings and shoot in Program mode and see what happens.

[SPell]

I was shooting during the day.  Shoot some images side by side with my 7d and the 7d images were exposed correctly.  I didn't have the issue with my first 5d mk iii.  I've read on a couple of different sites and it seems to be a somewhat common issue. I reset all setting to factory and will go from there. 

[ebiggs1]

"... reset all setting to factory and will go from there. "

This will fix it. You have a setting jacked up which is adding exposure.