A/C problem and question on PSI

[X5tmfore]

Hey guys my 2010 X5 has started blowing warm air on the passenger side, driver side is still cold. I know this is typically a sign of low refrigerant (R134a). That being said, I am trying to find out what the spec is for psi in the system. I see under the hood they have 1.54 (+/- 0.02 lbs). Cautiously I am assuming the 1.54 is in bars but then why print the variance in lbs? Can someone tell me what the actual PSI should be in psi. My gauge is reading 22.50 which would indicate that the pressure was correct if my assumption of bars is right. That would lead to my next question, if the pressure is correct, and I am getting cold out of the drivers side (compressor is obviously working) then could it just be a stuck heat flow valve? Any thoughts appreciated, thanks! By the way I have tried adjusting all of the in cab AC controls and the hot/cold settings for each side.