A/C ON & ECO not selectable when engine is on?

[WRJ11]

Hello!

I have a A4 B9 (2016) and noticed today whilst driving that my AC was stuck in the off position. When I try to click it upwards to ECO or ON they just appear faintly but it doesn’t change. Weirdly this only happens when the engine is on, if I just have the ignition on they are both selectable like normal. Anyone have issues like this?

 

[Sibmets]

Hi, it sounds like You have a problem witch AC and it's not switching on, 'cause it should cycle between modes while eng is on.
Have Your car checked for fault codes, something's is up.

Audi A4 B9 3.0 TDi quattro 200 kw

 

[WRJ11]

Hello! Thanks for your reply! I’ve got a Carista so will plug that in today and see if it brings anything up.
How are you finding your 3.0Tdi 200kw? I have the same engine!

 

[Sibmets]

Love it, so much torque, so smooth, goes like a rocket, sounds okay and has excellent fuel consumption at the end of the day. It
How's Your impression of it?

Audi A4 B9 3.0 TDi quattro 200 kw

 

[WRJ11]

Yeah I love it, heard a remap makes it even smoother, but will wait until I’m out of my approved used warranty for that haha. What does yours idle at usually? Mine loves to idle at just under 1000rpm and it feels like it wants to lurch forward, but then after a while will drop down to ~650rpm and is buttery smooth.

 

[WRJ11]

So I used Carista to have a look for faults. Found quite a few!

Central Electronics -

65685 - Heated seat Backrest, Front right - Open or short to plus
1123601 - Manufacturer specific

Heater & A/C
262914 - Manufacturer specific

Driver assist Front sensor
1123671 - Fog Assist Active
1123600 - Manufacturer specific
1123601 - Manufacturer Specific

Front passenger door
196630 - Manufacturer specific

Infotainment system
03084 - Ignition limitation belt-tensioning passenger side (G552)

Body Convenience system
65642 - Manufacturer specific
65643 - Manufacturer Specific
65644 - Manufacturer specific
65645 - Manufacturer specific
65907 - Manufacturer specific
65906 - Manufacturer specific


Think I’ve opened a can of worms here!

 

[Airfan]

You have no refrigerant. 262914 - Refrigerant Pressure
You have to fill the system with refrigerant and check for leak spots before that.

 

[WRJ11]

Thank you AirFan! Do you know if it’s typically a warranty issue or is it just a normal thing that happens?
Any other codes you see here of great concern?
Thanks

 

[Airfan]

It should be warranty issue. It is not normal to loose it so fast. Many people doesn't know but the A/C compressor should be started at least few times every month even you don't need it, so the oil inside lubricates the sealing and prevents the refrigerant to escape in the air. Usually in the garages they fill the system with mix of oil, refrigerant and fluorescent stuff so next time when you have a leak it will be visible if you light it with UV light.
It is not uncommon to see where the leak was with naked eye because the oil escapes with the refrigerant and it lubricates the surrounding parts.

 

[WRJ11]

Ah perfect! So the car is just over four years old. And I have the A/C on quite regularly even in the winter. I’ve heard stone chips can damage the A/C radiator? Is this true?

 

[cuke2u]

You just have to leave the climate on auto all the time, that's what it's designed for. I don't think the b9 has a particular issue with stone damage to the condenser, certaintyno more than any other vehicle. If you car has never had the air con service then suspect low refrigerant first and foremost. Plus it might have the climate unfriendly R-134a refrigerant, manufacturers have now switched to R-1234yf and will replace the versions our 2016 cars came with. Mine has been done..

 

[Airfan]

I don't think it is common to damage the condenser but it can happen as in any other car.
I don't need the compressor in the winter so I leave it off. It comes back one when I activate air recirculation and I do that at least once in the week due to old diesels so it works at least once a week. Then in the autumn and summer it is almost always on. I don't like the A/C smell even in the brand new car I can scent it so I avoid using the A/C when possible.

 

[Sibmets]

Yeah I love it, heard a remap makes it even smoother, but will wait until I’m out of my approved used warranty for that haha. What does yours idle at usually? Mine loves to idle at just under 1000rpm and it feels like it wants to lurch forward, but then after a while will drop down to ~650rpm and is buttery smooth.

Yap, same for mine - idles cold ~1000, hot ~650. Love that the torque and gearbox combo allows me to drive at 8th gear with 800 rpm at around 70-75 km/h and feel no vibration, my old B7's 3.0 TDI 6-speed manual didn't love rpm below 1100-1200 if I remember correctly. Quite awesome how modern engines are now, don't You think?

Audi A4 B9 3.0 TDi quattro 200 kw

 

[WRJ11]

You just have to leave the climate on auto all the time, that's what it's designed for. I don't think the b9 has a particular issue with stone damage to the condenser, certaintyno more than any other vehicle. If you car has never had the air con service then suspect low refrigerant first and foremost. Plus it might have the climate unfriendly R-134a refrigerant, manufacturers have now switched to R-1234yf and will replace the versions our 2016 cars came with. Mine has been done..

I don't think it is common to damage the condenser but it can happen as in any other car.
I don't need the compressor in the winter so I leave it off. It comes back one when I activate air recirculation and I do that at least once in the week due to old diesels so it works at least once a week. Then in the autumn and summer it is almost always on. I don't like the A/C smell even in the brand new car I can scent it so I avoid using the A/C when possible.

Thank you both for your replies! Got it booked into the dealer for them to have a look! Weirdly on a 4 hour drive today it seemed to come back on and function properly so I have no idea what is going on haha!

Yap, same for mine - idles cold ~1000, hot ~650. Love that the torque and gearbox combo allows me to drive at 8th gear with 800 rpm at around 70-75 km/h and feel no vibration, my old B7's 3.0 TDI 6-speed manual didn't love rpm below 1100-1200 if I remember correctly. Quite awesome how modern engines are now, don't You think?

Audi A4 B9 3.0 TDi quattro 200 kw

Ah that’s good to hear it’s normal! Yeah love how smooth it is on the motorway!

 

[cuke2u]

I don't think it is common to damage the condenser but it can happen as in any other car.
I don't need the compressor in the winter so I leave it off. It comes back one when I activate air recirculation and I do that at least once in the week due to old diesels so it works at least once a week. Then in the autumn and summer it is almost always on. I don't like the A/C smell even in the brand new car I can scent it so I avoid using the A/C when possible.

The compressor is low torque, I think that's what it's called, has a clutch and will not be on below a certain temperature. It is the compressor seals and bearings that can fail if not used frequently but the choice is yours if you nose is so sensitive. Can't say I can smell anything in the winter. Any smells tend to be from a unlooked after system allowing bacteria to buildup...

Edit: ignore me, just remembered that even though the system is turned off I don't believe it it actually fully off.

 

[Sibmets]

I also don't smell anything on my B9 and I leave AC on "AC eco" all the time.
I've also heard that the smell is due to bacteria which build up when system is not in use.

And a little rant from me on the age old question - AC On or OFF:
For me, the only reason to then to turn it off would be the fuel savings, but after some experimenting after driving home from night shifts (around 6 am, the same route, traffic lights, trafic, outside temperature, driving style) I noticed that there's no noticable difference in fuel consumption, it's less than 0.3 l/100km in my case. It didn't matter the AC is off or ECO, the fuel consumption would be 5.1-5.3 l/100km during 4 nights in a row (I drovein super ECO lazy mode and there was literally no other cars, didn't have red lights also).
This, mind You, is for B9 3.0 TDi 200kw sedan, O guess it's due to its efficient compressor and ECO mode operation. For my previous car (B7 3.0 TDi quattro sedan) it was a different case, with AC ON the range would drop around 10% and I would notice increase in fuel consumption in the same driving conditions in daily commute.

Audi A4 B9 3.0 TDi quattro 200 kw

 

[Airfan]

I know what the smell of bacteria in A/C is. But I always can scent when A/C is working and it is different than the mold smell. It changes the air. The B9 I have has 22 000 km on the clock and the previous one I bought (Toyota) was 7 km on the clock and still I can scent it. Probably it is I that is deviant having sensible nose

 

[cuke2u]

I also don't smell anything on my B9 and I leave AC on "AC eco" all the time.
I've also heard that the smell is due to bacteria which build up when system is not in use.

And a little rant from me on the age old question - AC On or OFF:
For me, the only reason to then to turn it off would be the fuel savings, but after some experimenting after driving home from night shifts (around 6 am, the same route, traffic lights, trafic, outside temperature, driving style) I noticed that there's no noticable difference in fuel consumption, it's less than 0.3 l/100km in my case. It didn't matter the AC is off or ECO, the fuel consumption would be 5.1-5.3 l/100km during 4 nights in a row (I drovein super ECO lazy mode and there was literally no other cars, didn't have red lights also).
This, mind You, is for B9 3.0 TDi 200kw sedan, O guess it's due to its efficient compressor and ECO mode operation. For my previous car (B7 3.0 TDi quattro sedan) it was a different case, with AC ON the range would drop around 10% and I would notice increase in fuel consumption in the same driving conditions in daily commute.

Audi A4 B9 3.0 TDi quattro 200 kw

It's doubtful that there would be any fuel savings when the climate is turned off as, from past posts, it was discovered that off is still on...

 

[Watson10k]

Thank you both for your replies! Got it booked into the dealer for them to have a look! Weirdly on a 4 hour drive today it seemed to come back on and function properly so I have no idea what is going on haha!



Ah that’s good to hear it’s normal! Yeah love how smooth it is on the motorway!

I can see this post is from some time back, but did you find out what caused this AC issue?