[marty1]

There is a software update to help address this on '07 and '08 models. See TSB 07-062 attached.

 

[marty1]

You can try replacing the compressor relay (it's in the fuse box by the battery). It's not very expensive.
More than likely you've run up against the nagging problem that plagues this generation. Compressor clutch failure.
It cannot be diagnosed until it fails. Your symptoms match exactly what a failing clutch does.
The dealer will fix for about $700.00, local A/C show for probably half that or if you're mechanically inclined you can do it for 100+.

TSB 12-072 (link below) details the clutch replacement. The '07 to '11 models had bad clutches. Unfortunately the 7 year warranty extension has run out.

https://static.nhtsa.gov/odi/tsbs/2014/MC-10129324-9999.pdf