Heat does not come out on passenger side or rear out lets. To get it reasonably warm throughout I shut the Passenger side vents off yo keep the cold air to a minimum. Driver side heat works great!!!

Try a system relearn.
The module needs to learn the full open and full close positions of the doors.
AC reset
Turn the system on full cold Max AC.
Radio OFF.
Turn ignition OFF.
Pull the HVAC (AC) fuse(*) from interior fuse box. Leave out for 1 minute and replace.
Turn key to run/on position....NOT start.
Do not touch any controls. You'll hear the doors (actuators) being opened and closed. The HVAC module is learning the full open and full close positions. Wait until the system is completely done with the learning process. Less than a minute.
Start and test the system.

I will give that a try later today, I asked the local fixit shop they asked if I heard clicking at any point, The answer was "yes" about a month back it was quite noisy one moning I did not pay much attention as it stopped. They said the actuator is the likely problem, will let you know.
Phil

When it goes through the learning process you will be listening for the actuators to move the doors you will know if an actuator is bad as it will click quickly. Thus the reason for having the radio and stuff off so you can hear it.

Did not get to do it today will try for tomorrow.

Do we have heat?

Sorry did not get to it, my neighbor had a problem, I just ot back in the house chilled to the bone. Hopefully tomorrow!
Oldphil

No clicks No heat on her side, called dealer he said could be $600! I have tape and plastic to cover her vents. When it is real cold will fire up the Sub it has great heat.
Phil

Yeah, even for little stuff, if the repair gets into a couple of hours of labor then you could easily end up there.

Kind of lost interest, but the chill is coming back. No one wanted to tackle the job, I took it to Buick they asked what mode; does it have a console etc. Well the stunning answer was $1,700 due to the removal of both the dash and console. He gave me an idea, he said pull the cabin filter then cover it with tape and put it back. That will block off the outside air, I did it time will tell!