newmoon

Ok, so the dealer fixed mine under warranty. Took about 45 minutes. This is what the repair order says:

Internal malfunction of AC pressure switch G395
1) GFF DTC #265/AC switch/Malf. in 08 and 09 group
2) Replace AC pressure sensor G395 as per attached TSB# 2020124/12

4H0-959-126-A PRESSSENS
7H0-820-896 SEAL RING
ZVP-000-134 R134

dwboston

I've had some weird behavior with the A/C and 4-zone climate control in my 2012 A6 as well, most notably: different fan speeds and different temps blowing from the driver and passenger side vents (driver's side always feels warmer), despite the same temp set on both sides and SYNC being selected. This issue happens often.

The most unusual issue occurred over the winter - I was driving home from dinner with my wife and had the heat set to 72* on a cold night. After the car warmed up, the air blowing from the vents was noticeably hot. I changed the temp setting up and down, but it had no effect and kept blowing hot air. I shut the climate control system off, then turned it back on, but it still blew hot air no matter the temp setting. It wasn't until I pulled over and shut the car off and restarted it that the temperature normalized, and it hasn't happened again.

I'm bringing the car in tomorrow for the 45K service and have asked them to take a look at it. Hopefully it's something as simple as the A/C pressure switch.

newmoon

When I was researching my issue of having no A/C at all, I did come across some stuff about having different temps coming out of each side. They are for the C6 A6, but maybe it's worth investigating anyway:

https://www.audiworld.com/forums/a6-...vents-2756309/

DB22

The 4 zone reminds me of the Tesla, a great car but they screwed up on something others mastered years ago.

irenesbob

After reading these posts I took a stern look at what my '13 A6 has been doing for over a year now and decided not to live with it any more. It is going in to the dealer Thursday. Sometimes I tend to live with things if they do not interfere with a car's basic "drive me to point X" function, but these posts pushed me to be a more demanding consumer I guess.

WJohn

Just got back from the dealer after AC went dead over the weekend; and as stated in this and other threads it is a known problem for these models. The service advisor was not surprised and even stated that there is a campaign (nice word for silent recall) out for the pressure sensor.

Quoting the service sheet: "Please perform Campaign 87D9 AC/Pressure Temperature Sensor
Cause: Campaign 87D9"

My A6 is still under warranty, unsure if there would be a charge if it were not...but this being a known problem, I would hope that Audi does the right thing for those with expired warranties.

AC is working perfectly now in the 93 degree heat in the south. Took less than an hour to fix...unfortunately it's almost a 2 hour drive to the dealer.

DB22

The direction, temperature and fan speed is dependent on the weather in Ingolstadt, the phase of the moon in China and the number of dead chickens on the roads in Sarawak. Coincidently, those conditions are occasionally met here in the US and it works fine but I would not put the Audi designers in charge of a global warming solution.

irenesbob

I had the car in to the dealer yesterday. It is an 86 mile drive, and after 15 minutes or so of cool air from the passenger side vents it was hot air only and constantly from that side all the way down. After less than an hour the car was ready and they said everything was OK. The work order said “checked basic settings on AC, found no stored faults in system. Found operating to Audi specs at this time.” The service guy said they had put in the “latest sensor” in summer of 2014 – something I had not been told before. I was skeptical and assumed that after a half hour or so of driving the heat would start blasting out again. I then drove back home and took a detour, meaning the car was running non-stop about one and a half hours and then several quick runs of startup, shut off, restart, etc. At no point did it start spewing hot air from the passenger side – everything was “normal”, as was the case this morning.
I am suspicious. It has been screwing up for months, was screwing up on the way down to the dealer. They looked at it, they did nothing and now it seems fixed.
Is it possible that they left something unconnected or awry after the install of the new sensor last summer (it was about that time I started noticing the issue), did they not really do it last August and actually did it yesterday, or is it just luck?

Update:
I checked the paper work and sure enough, in August '14 they did the following: "AC Pressure/Temperature Sensor (NVLW) Perform 87D9 RVU Pressure Switch Remove+Reinstall." It is funny was right after this that I first noticed the right side blowing hot air for prolonged periods when the left was blowing cold - hmmm

jonet

I have noticed problems with the AC at only one occasion. My passenger turned up the heat but she was not happy and turned it higher. I turned it down on my side to compensate. After a while we found out the she got cold air and I got hot as if the right side **** controlled the left side and the left side **** was controlling the right side. After a stop the HVAC worked as normal.
After this I try to have the HVAC in "sync" at all times.
I have always suspected that this was a software bug, I don't have an error message for the AC pressure sensor.
I mentioned it to the dealer but they never update any software unless AUDI Germany tells them to or if you pay them. And he had never heard of this problem.
I don't know but could it be that you get the latest software also for the HVAC if you pay for a map upgrade?

DB22

No, only if you get a tire rotation