He HVAC temp control isn't working. When in any position other than full cold or full hot, I can hear a slight 'thump' from under the dash. It will permit all hot OR all cold temp but no in between.
Any suggestions?

 

Yep, take it in.

There is a TSP for the blend door failing; TSB 08-23-6
http://www.google.com/url?sa=t&rct=j...YvKUI2d7ZM2k8Q
The above link is from googling "TSB 08-23-6"

Mine was doing the exact same thing. Unfortunately, it wasn't the blend door, mine was the entire HVAC control unit. I was at the very tail end of my warranty so it was covered.

Good luck!

 

^^X2, same thing on my 08, full hot or full cold. Replaced blend door actuator under warranty and all good. Part is cheap, like $25 i think. Can access from behind glove compartment door.

 

Super!! Thank you both. I just bought it and no temp control is really not cool.

 

I have an 07 with this issue that is no longer under warranty. Where can I get further instruction on how to replace the blend door actuator? Sounds like ths isn't too difficult to replace.