Just had the low pressure line replaced and a/c serviced. What I have noticed is the air on the driver's side is warmer than the passenger side. I checked the ACC codes - reads 0, no codes. If I understand correctly when you check for codes - it also re-calibrates the stepper motors? Have checked this multiple times.
Yesterday I had to make about a 30 minute trip out of town. Driving out the passenger side was 30+ degrees below outside air temp - awesome, drivers side was 20 degrees below OAT . On the drive back the passenger side was only 20 degrees below OAT - drivers side maybe 10 degrees below OAT. After I got into town and slowed down, something changed and it got cooler, 30 & 20 degrees below OAT. Is there one door that has some control on both sides? I didn't reach around and feel the back air. The entire time I had left the system on AUTO.
On a side note - the HVAC has always had a humming noise at certain fan speeds - doesn't sound like a motor noise, always felt it was like a control door not closing and vibrating.