C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

Climate control blows either too hot or too cold

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Old Dec 27, 2019 | 03:46 AM
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W203 m271
Climate control blows either too hot or too cold

Hi guys
Im having a problem with the cabin temperature. It blows either too hot or cold. The problem persist
Even ac is on or off
Even with AUTO on or off.
Reset function didnt solve the problem.
I have a delphi diagnostic and what i have see is that the temperature controller change the footwell flaps position (i can understand thats what controls heat/cold right?) only in the very hot or very cold. When i go back from the "click position" the flap position goes to the oposite side,it doesnt take me middle values.
And the most strange. The flaps take every middle value is set when the windows comes down.
Here are some photos from the sensor values. What i havent find is the value of the temp sensor in the panel that controls the pano roof (there exist a sensor,right?) And i cant find any data in the delphi for this unit. Maybe because they are just switches?The rear sam has to do with this unit? I have some error codes also.Also what is the dewpoint temperature?

PS. One thought is that the problem happen when i use a vacum cleaner and put it in the grill of the ac controller. Or it was coincidence

Here are some photos from the diagnostic reader





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Old Jan 2, 2020 | 01:45 PM
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W203 m271
Happy new year!
Any suggestions?
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Old Jan 6, 2020 | 10:44 AM
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W203 m271
I started disconnecting sensors and check how ac blows air. I started with evaporator temp sensor and then air humidity sensor. Works the same. Then i disconnect the OCP and (i think after ac reset) it started blowing air in the correct set temperature! Didn't test auto function. Then i disassembly the OCP and saw that the temp sensor has one leg cut. The wire was fragile and cutted by touch three more times, but i manage to solder what has left. After the soldering i check with multimeter and i saw the ohms changes when you heat it.i also put the board as it is to verify ac still works, before reassembly. Ac blows the air that is set and auto function works again!






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Old Sep 4, 2024 | 05:24 AM
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w203 mercedes benz c200 2001
where is this board located? i think i have similar problem
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