Hey guys. I've searched and searched and cannot find a clear answer for my situation. I have a 2014 CLS550. So, my issue is that the dual zone climate control doesn't seem to operate correctly. I noticed it last summer but didn't pay much attention to it. So during the summer time, if I set the controls to both sides 70, the drivers side would blow hotter than the passnger side. The passengers side always felt cooler so I would lower the drivers side even more to match the passenger side. On really hot days, i would set both sides to max lowest temp. But again, the passenger side would always be colder. I thought it was a low freon issue. But, since it was nearing winter time, I decided to ignore it and wait til next summer to fix it. But, now it's cold. And the same issue is now reversed. I set both sides to 80 degrees. The drivers side is hot, the passengers side is cooler. This go around, i do not even use the A/C function so I can't say its a refrigerant issue. To get both sides to feel about the same temp, if I set the drivers side to 80, I have to set the passengers side to 84. It seems that both sides have this 4 degree difference no matter where I place the temp buttons. I'm inclined to say that the drivers side one is the bad one. I say this because of my experience with it in the summer time, it was never really cold. The passengers side blew the really nice cold air. So it seems the drivers side is set 4 degrees warmer than indicated on the knob.

My question is I guess, is there a blend door actuator? My old Cadillac DTS had 2 blend door actuators that controlled the driver side and the passenger side. I pulled a parts diagram and only see one actuator for my car. And it is listed as the recirc/fresh air actuator so I don't think its the part I am looking for. I read about duovalves but it was in the older Benz's. I don't believe this CLS has that. Where are the blend doors and how are they controlled in this car? Or maybe there is a temp sensor issue? I do not have access to a code reader to find codes. And I'm trying to avoid taking it in. I know for my DTS, blend door actuators were really cheap, like $30 each. If there are blend door actuators on my CLS, and they aren't terribly expensive, I don't mind doing a parts throw at it hoping to fix the issue. It may fix it and I avoid a dealer trip. Win for me. But if there is no fixing this at all without a dealer trip, I'd like to know that as well.


Jason

 

Temperature differences between the driver and front passenger side are normal in certain model series and compensated by regulating manually. Reactions to changes in the target temperature on the operating unit may vary considerably from vehicle to vehicle depending on the engine heat output, the ambient conditions and other influencing factors. In each case the control unit selects an optimized control curve to achieve the best possible adaptation.

Having said this best to have someone proactively pull fault codes. There are four temperature sensors: left/right (b10/31-32 as depicted in dashboard attachment) not certain if they can be accessed by simply removing vents, driver & passenger foot well (b10/36) all same part # 2218300872 https://mbworld.org/forums/e-class-w...or-wiring.html

 

Thanks Konig for the information! I was hoping to avoid having the car taken in for code reading. The only reason I was going to get this fixed is because summer is coming and I don't feel like dealing with the not as cold air on the drivers side.. it is consistent in not being cold like the passenger side. It's especially bothersome when it is super hot out. It takes forever to cool the car down because it's not fully cold. I was hoping there was a blend door that either was stuck or had a bad actuator. I was hoping I could replace those in the garage easy peasy. The temp sensors look like I have to remove some stuff but I might be able to swing that.

Konig, do you know if there are blend doors? How does does car maintain different Temps on each side?

 

Concerning AC I would suggest refrigerant.