HVAC PROBLEM

[Steptronic]

Hello,
Sorry for my bad language. Recently noticed that the air conditioner has gone faulty, it's blowing half hot and half cold when A/C is set to Cold. I have 4 zone climate control.
Hot: Passenger Side Vent & Passenger Center, & Drivers Side Vent, & Rear Center Vent.
Cold: Only Drivers Center
Adding photo with explanation : https://imgur.com/a/XF4RrWr

I connected (VCDS - VAG COM) diagnostic software. But HVAC has no faults. Tried to read some adv. meas values. Adding photo https://imgur.com/a/Yrbzero
In my opinion compressor is working, because refrigerant pressure is raising to 13-14 bar and compressor torque to 16.6055 nm. Maybe refrigerant pressure is to low, and sensor of pressure is lying ?

Has anyone else experienced a similar problem?
Thanks in advance.

[Ellandauer]

I have an issue right now with my HVAC system. Thought it was the AC pressure sensor switch as that was shown faulty on VCDS but still no cold air. Taking it to an AC repair shop on Wednesday to diagnose and see if something else is the issue. I may have leak and not realize it. Will update again after diagnosis on wednesday.

[WatchMeSpend]

Had this happen on my C6 A6. This was the culprit:

A/C HVAC Heater Control Valve 4F1959617B 4F1959617A 4F1959617 For Audi A6 / S6 / A6 Quattro 2005 2006 2007 2008 2009 2010 2011

[Steptronic]

Had this happen on my C6 A6. This was the culprit:

A/C HVAC Heater Control Valve 4F1959617B 4F1959617A 4F1959617 For Audi A6 / S6 / A6 Quattro 2005 2006 2007 2008 2009 2010 2011

Thanks for reply. Do you know where i can find this "heater control valve" on C7. Because on C6 is under plastic from the back of the engine. But on C7 no information where is can be.

[3g_bishi]

Thanks for reply. Do you know where i can find this "heater control valve" on C7. Because on C6 is under plastic from the back of the engine. But on C7 no information where is can be.

On the c7 it’s under the plastic behind the engine as well easy to get to.

You have many ways of diagnosing, repairing and even bypassing this.
If you want to diagnose it, you need to put gauges on and make sure you are full on Freon, if you are and the pressures are good you have a blend door or heater valve issue.

In that case you can either bypass both completely (will leave your without heat but your ac will
Work)
Or you can replace. The heater valve is easy to replace. The blend door actuator although unlikely is the issue is very hard to do.


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[Steptronic]

On the c7 it’s under the plastic behind the engine as well easy to get to.

You have many ways of diagnosing, repairing and even bypassing this.
If you want to diagnose it, you need to put gauges on and make sure you are full on Freon, if you are and the pressures are good you have a blend door or heater valve issue.

In that case you can either bypass both completely (will leave your without heat but your ac will
Work)
Or you can replace. The heater valve is easy to replace. The blend door actuator although unlikely is the issue is very hard to do.


Sent from my iPhone using Audizine

Thanks for reply. Next week i registered for refrigerant refill. Although Vcds showing that refrigerant pressure is growing to 14 bar. Can you show me photo of "heater control valve" because under plastic in center i see only two hoses https://imgur.com/a/npJ57Dp

[3g_bishi]

Thanks for reply. Next week i registered for refrigerant refill. Although Vcds showing that refrigerant pressure is growing to 14 bar. Can you show me photo of "heater control valve" because under plastic in center i see only two hoses https://imgur.com/a/npJ57Dp

All the way In the corner on right side(facing the radiator) passenger side in USA. It has a electrical connector and 2 hoses.


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[Steptronic]

Changhed A/C pressure switch, and refilled new refrigerant. Now everything working fine.

[MattyG07]

I have an issue right now with my HVAC system. Thought it was the AC pressure sensor switch as that was shown faulty on VCDS but still no cold air. Taking it to an AC repair shop on Wednesday to diagnose and see if something else is the issue. I may have leak and not realize it. Will update again after diagnosis on wednesday.

Hi, Can you confirm diagnosis from repair shop? I have same issue on my 2017 A6 and replaced pressure sensor but no fix. Thanks