Air Conditioning blows hot?

[andyroxs]

My 2012 A4 has a broken AC (only blows hot air), and I am wondering if anyone has any tips for how to trouble shoot. Took it to two shops and they both said to go to the dealership.

- Compressor kicks in
- r134/freeon is not leaking
- No visible wire damage.

Have heard people saying G395 sensor and some saying the hot/cold air flap, I am just unsure how to proceed with diagnosis. Plugged it into carista and got a bunch of codes.


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[Iridium.]

Did the two shops you took it to, evacuate the system and weigh the amount of refrigerant in there?

Edit: There has also been an update to the G395 Sensor. You may need to update to the newest one and the temperature flap my be a sympathetic symptom in relation to the failed sensor.

Edit: Edit: If it is indeed related to the temperature flap, you may be able to run basic settings with VAG-Com on the Flap Motor Module.

[andyroxs]

Did the two shops you took it to, evacuate the system and weigh the amount of refrigerant in there?

Edit: There has also been an update to the G395 Sensor. You may need to update to the newest one and the temperature flap my be a sympathetic symptom in relation to the failed sensor.

Edit: Edit: If it is indeed related to the temperature flap, you may be able to run basic settings with VAG-Com on the Flap Motor Module.

thanks for the reply. does the G395 also apply to the 2012s? is that a TSB?

[Iridium.]

There is a bulletin for the sensor. See below for more info.

[andyroxs]

oh nice, thanks! how do TSBs work? do I have to be in warranty for the item to be replaced free of charge? Eg for the PCV TSB, I have to be in warranty for that as well?


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[Iridium.]

oh nice, thanks! how do TSBs work? do I have to be in warranty for the item to be replaced free of charge? Eg for the PCV TSB, I have to be in warranty for that as well?


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Generally, once you're out of warranty bulletin's are informational only. Provided you got all, and I mean all of your servicing done at an Audi dealership, there's a slim chance Audi of America would goodwill the service.

Did you purchase the car new or CPO'd?

[andyroxs]

Generally, once you're out of warranty bulletin's are informational only. Provided you got all, and I mean all of your servicing done at an Audi dealership, there's a slim chance Audi of America would goodwill the service.

Did you purchase the car new or CPO'd?

bought it new. guess I'm SOL, good thing that sensor isn't too expensive. hope that solves it


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[blbroo]

MY A/C started blowing warm, then would kick back off instantly after I pushed the button. I replaced the sensor (4H0959126a) on Friday, hoping that was the answer, but no luck. Added some 134A Sunday and I had cold AC again, for a day. Now it is back to blowing warm. The sensor takes 15 minutes to swap and is under the plastic cover that you can remove to access the area behind the grille / in front of the radiator.

I'm suspecting a leak somewhere, so I'll use some of the UV dye and a light to try to find where I am losing refrigerant.

[andyroxs]

can't you check the pressure quickly under the hood and see if you're leaking first?


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[blbroo]

can't you check the pressure quickly under the hood and see if you're leaking first?


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Yeah. I did that and the pressure has dropped.

[andyroxs]

was that sensor the 395 sensor or are there other ones!


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[buelldozer]

When this happened to me my compressor wouldn't engage. When I dropped the belly pan it turned out a mouse ate the control wires to the compressor!