exhaustgases

No bad codes and refrig pressures are okay, pump works.
I think it is the flapper valve or what ever that directs the hot or cold air.
How hard is it to get at? When running the diagnostic I think all worked good. Are there servos that operate the valve? If bad they should throw a code?

Yidney

A bad servo will not throw a code you can read, but MB's SDS can read them.

Scott Simoncic

Grab the low pressure line while running, is it cold? What is your low pressure while running?