What causes the passenger air to blow warm when the drivers side is cold? on 2006 Buick Lucerne

The temp is set the same on both sides, but hot air comes out of the passenger vents.

Asked by for the 2006 Buick Lucerne
blend door motor. you need a shop with a scan tool that can operate the doors to test them.

Thank you sir. I know a shop with a Scan tool.