Back Seat Freeze or Bake from Climate Control

[xsnrg]

I have an '06 Avy Limited, well beyond warranty. Last year sometime my wife and I noticed that the back seat vents seemed to be either extremely hot or extremely cold, no mix in between. Back seat should get same mix as the passenger up front, correct? The dealer told us there was a motor or flap control deep in the dash that controlled this and it must have gone bad. Gave us a $1200 repair estimate to fix based mostly on labor to completely remove and reinstall the dashboard to get to it. Has anyone else experienced this? Any insights or experience on getting it resolved without such a hefty payout?

[inov8]

Copied from factory manual, page BE-68:

"Air Conditioning ECU has a self-diagnosis function. It stores any operation failures in the air conditioning system memory in the form of DTC (Diagnostic Trouble Code).
There are two methods for reading DTCs. One is to use a hand-held tester, and the other is to read the DTC on the heater control panel switch. DTCs are shown on the center display or multi display of the multi-information display, and on the
hand-held tester."

Did your dealer use his scan tool to read the codes before recommending a $1200 fishing expedition?

[XXagon]

Check to make sure that the left and right underseat vents are not blocked by a carpet or other objects. This may cause the air to back up and be redirected to the Rear Console vents.