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Air Conditioner is WEAK

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
I can tell that my car is very much improved since i did the Hot climate change. my car also had 1000 miles on it before I owned it so it did get used more than the average ones I have seen posted here.
my car is over 6000 miles now and I havent had any other issues with weak AC since i changed it over.
This is what I really wanted to know. Thanks. I am going to have to cave-in and get a vcds or find a new friend to make that adjustment for me.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
In other news, I did the "hot country" modification with VCDS on the 2015 Golf yesterday, and it does seem to make a difference.

How certain are you that this helped? I would like to know before I start trying to get bucks for a vcds purchase or bother a forum member to help me adjust my wife's and Dad's cars.
 

PaulL

Member
Joined
Feb 8, 2017
Location
Houston, TX
TDI
2015 Golf TDI S
There has been plenty of discussion about inconsistent AC systems over at vwvortex. If you have a VCDS you can check to see if you have "Hot Country" enabled. It seems like there are some cars sold that had it enabled and others that didnt. Reading through the thread below, people have reported getting cold air much faster after making the VCDS tweak.

http://forums.vwvortex.com/showthread.php?7974521-2015-GTI-VCDS-AC-quot-Hot-Country-quot

Instructions from the link above:

1) Open VCDS
2) Go To Select Modules
3) Under the "Installed Modules" window - select number 08 - Auto HVAC
4) After the control loads - select Coding - 07
5) Click the button for "Long Coding Helper"
6) Press Tab or arrow down key until you see "Byte 12" selected
7)Under the drop-down for "Bit 4-7" select "10 Temperature Adjustment: Cold (Hot Countires)"
8) In the top-left corner of the window - select the "Exit" menu item
9) Press the "Do It" button to save the new setting
10) If all goes well - you should see a popup "Coding Accepted"

I haven't done this myself or checked what my setting is since I am happy with how my AC performs. Might check just to see what my settings are just for kicks.
Thanks for sharing. I made the change to HOT COUNTRIES on my 15' TDI S and the difference is very well noticeable in Houston summer.
 

Growler

Got Soot Vendor
Joined
Nov 24, 2003
Location
Millersport, Ohio
TDI
Schmutz, 2015 Golf Sportwagen DSG & Schnurren, 2001 Golf GL 2 door 5M
It is very apparent that the AC when switched over to HOT COUNTRY as above works better to cool the cavernous interior of the GSW with the black leatherette and no tint...

I have however noted about a 2mpg/tank drop since i did the change, but I prefer for my passengers and myself to be comfortable way more than I prefer higher MPG...
 

Bob S.

Top Post Dawg
Joined
Aug 17, 2006
Location
Central MD.
TDI
A B4V, some ALHs & BRMs
How certain are you that this helped? I would like to know before I start trying to get bucks for a vcds purchase or bother a forum member to help me adjust my wife's and Dad's cars.
You will not regret a VCDS purchase. A basic tool for working on these cars that will pay for itself many times over in both out of pocket costs and troubleshooting time. In the interim, hopefully you can find a VCDS equipped owner to assist you now.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Also disable the auto lock on the doors while driving, its just a waste of the motor life!

unless you drive through sketchy areas and worry about car jacking, if that's the case drive a beater and drive the VW in better parts of town.
 

VeeDubTDI

Good Ol' Boy, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
It is very apparent that the AC when switched over to HOT COUNTRY as above works better to cool the cavernous interior of the GSW with the black leatherette and no tint...
I have however noted about a 2mpg/tank drop since i did the change, but I prefer for my passengers and myself to be comfortable way more than I prefer higher MPG...
Good info about the MPG change when switching to hot climate mode.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
Growler, Holy Crow 2 mpgs is a pretty big hit. I agree that it is worth it especially for my 85 yoa Dad but that hurts my feelings.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
You will not regret a VCDS purchase.
I really want one and in honesty the cost isn't that big a deal. The trouble is I feel overwhelmed every time I go to their website I don't know what the heck they are talking about, I don't know which unit I need nor do I understand the difference between them. I went on line in the past to buy one and just gave up several times.

I have watched a couple of people using VCDS and it looked like Egyptian hieroglyphs to me. Then add on the fact that my memory sucks BAD. I will take the time, sweat mental bullets and learn how to use it but I know that next time I use it I will have forgotten how it works again. arrrgh!

And finally I worry that I will break something in the car.

After all this whine I have to admit I am going to pull the trigger this summer. I am retired now and I have the time (after the kitchen remodel, etc etc).

Thanks Bob, I think you have given me that final push I am gonna get one!!;)
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
Yeah I am trying to relax also. I don't even keep track of my mpg much anymore. I don't think I ever failed to compute the mpg in my MKIV by hand in nearly 300,000 miles of driving. Now I just drive and maybe every other tank I do the math. The read out is close enough.
 

Ted Hurst

Veteran Member
Joined
Jul 15, 2007
Location
44224
TDI
2015 GSW
Update: Dealer is replacing the whole compressor. Will report back.
Update: Dealer ordered the whole compressor but just replaced the N280 valve and sent the unit back. Air blows cold consistently and the lowest temp I could see with my mini thermometer is about 45 degrees F. This is with outside temps around 67 deg F. I'm wondering if how outside temps regulate AC operation? I will report back when we get a nice hot humid day.
 

Growler

Got Soot Vendor
Joined
Nov 24, 2003
Location
Millersport, Ohio
TDI
Schmutz, 2015 Golf Sportwagen DSG & Schnurren, 2001 Golf GL 2 door 5M
Growler, Holy Crow 2 mpgs is a pretty big hit. I agree that it is worth it especially for my 85 yoa Dad but that hurts my feelings.

Remember that I am not the only driver of my car and my wife, god love her, does not drive the car for MPGs... so YMMV.

For me and my car the Fuelly/math MPGs/tank have gone down since I did the mod, but for me its still above 40mpg so I am happy.

The biggest thing that bothers me after having MK4s for so long is the tank size in these GSWs is so small that I have to fill the car up every week now instead of every other like I could in the mk4. its amazing how much a tank size change will affect things.

of course the MFA is still saying something like 45mpg average/tank so I still have to figure out how to get that be more accurate.. gonna be exercising the VCDS again I am sure for that one.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
If you lived nearby I would ask you for help on my Dad's (and my wife's) car to make the Hot Climate adjustment.

It is a shame they didn't make the GSW tank bigger. I've been really happy with the range on my Passat however.

Stay cool!
 

Ted Hurst

Veteran Member
Joined
Jul 15, 2007
Location
44224
TDI
2015 GSW
Update: Dealer ordered the whole compressor but just replaced the N280 valve and sent the unit back. Air blows cold consistently and the lowest temp I could see with my mini thermometer is about 45 degrees F. This is with outside temps around 67 deg F. I'm wondering if how outside temps regulate AC operation? I will report back when we get a nice hot humid day.
Update: With outside temps hovering around 87 the lowest temp I could read coming out of the vent is around 44 deg F. when moving and 50 deg F. when stopped at a light or traffic.
 

VeeDubTDI

Good Ol' Boy, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
So here is a thought of mine. Based on several reports here, the normal climate mode seems to set a supply air temperature of 45F, while the hot climate mode sets a supply air temperature of 35F. The lower the supply temperature, the more energy the system requires due to differential pressures between the evaporator and the condenser.

Now for a little tinfoil hat chat: I wonder if VW is setting the normal climate mode when they "fix" the emissions programming in order to maximize fuel economy. As Growler noticed, switching to hot climate mode results in a noticeable fuel economy penalty (2 MPG according to his initial testing).
 

2015vwgolfdiesel

Top Post Dawg
Joined
Jan 1, 2016
Location
Oklahoma
TDI
2015 VW Golf S DSG Silver
So here is a thought of mine. Based on several reports here, the normal climate mode seems to set a supply air temperature of 45F, while the hot climate mode sets a supply air temperature of 35F. The lower the supply temperature, the more energy the system requires due to differential pressures between the evaporator and the condenser.

Now for a little tinfoil hat chat: I wonder if VW is setting the normal climate mode when they "fix" the emissions programming in order to maximize fuel economy. As Growler noticed, switching to hot climate mode results in a noticeable fuel economy penalty (2 MPG according to his initial testing).
Bet you're right.

At least my car is cold for me. (now) Too cold really. I have to set the thermometer less than full cold. And the fan speed on low.

Will be watching the situation, after doing the fix
 

VeeDubTDI

Good Ol' Boy, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Bet you're right.

At least my car is cold for me. (now) Too cold really. I have to set the thermometer less than full cold. And the fan speed on low.

Will be watching the situation, after doing the fix
Keep in mind that the temperature controls for the HVAC are like a house thermostat. They control the cabin temperature set point. Setting it for maximum cold will generally result in you getting too cold. If you set it for 1/4 of the way up, you'll probably be more comfortable.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Is temperature in these cars regulated by the compressor cycling or mixing warm and cold air? If it's the former than I wouldn't think the hot weather setting would have a big impact on FE unless you're using the coldest temp all the time.
 

2015vwgolfdiesel

Top Post Dawg
Joined
Jan 1, 2016
Location
Oklahoma
TDI
2015 VW Golf S DSG Silver
Keep in mind that the temperature controls for the HVAC are like a house thermostat. They control the cabin temperature set point. Setting it for maximum cold will generally result in you getting too cold. If you set it for 1/4 of the way up, you'll probably be more comfortable.
Good advise - thanks
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
Is temperature in these cars regulated by the compressor cycling or mixing warm and cold air? If it's the former than I wouldn't think the hot weather setting would have a big impact on FE unless you're using the coldest temp all the time.
An earlier post said that the climatronic (or whatever) systems regulate the compressor cycling while the non-climatronic ones mix in warm air. I think in either case the high climate setting could make the system colder by lowering the set-point of the compressor in the non-climatronics and lowering the maximum set-point in the others. In my ignorant opinion
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
Now for a little tinfoil hat chat: I wonder if VW is setting the normal climate mode when they "fix" the emissions programming in order to maximize fuel economy. As Growler noticed, switching to hot climate mode results in a noticeable fuel economy penalty (2 MPG according to his initial testing).
Clever my friend VERY clever. I find your hypothesis plausible
 

VeeDubTDI

Good Ol' Boy, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Is temperature in these cars regulated by the compressor cycling or mixing warm and cold air? If it's the former than I wouldn't think the hot weather setting would have a big impact on FE unless you're using the coldest temp all the time.
On Climatronic, it's regulated mostly by compressor duty cycle. Once you get to the point that the system isn't cooling, it will start to add heat. Not having a car with Climatic, I can't say with authority, but I think it's similar.

Climatronic will really only mix warm and cold air if you're using the windshield defrost button, which will command 100% compressor duty cycle and add heat to maintain the cabin temperature setpoint. This trades efficiency for maximum dehumidification.
 
Last edited:

Bob S.

Top Post Dawg
Joined
Aug 17, 2006
Location
Central MD.
TDI
A B4V, some ALHs & BRMs
On Climatronic, it's regulated mostly by compressor duty cycle. Once you get to the point that the system isn't cooling, it will start to add heat. Not having a car with Climatic, I can't say with authority, but I think it's similar.

Climatronic will really only mix warm and cold air if you're using the windshield defrost button, which will command 100% compressor duty cycle and add heat to maintain the cabin temperature setpoint. This trades efficiency for maximum dehumidification.
Smart thinking on the emission base setting for efficiency.

Relative humidity often influences hot hot, or cold someone "feels".

In reading this thread, it makes me wonder if the comfort module is also taking in other atmospheric information, i.e.. the ambient outside humidity (often one of the MAF sensor data points) and using that in the programing of the compressor duty cycle?

If so, it could help explain some of the varied responses on how the system output is perceived.
 

VeeDubTDI

Good Ol' Boy, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Smart thinking on the emission base setting for efficiency.
Relative humidity often influences hot hot, or cold someone "feels".
In reading this thread, it makes me wonder if the comfort module is also taking in other atmospheric information, i.e.. the ambient outside humidity (often one of the MAF sensor data points) and using that in the programing of the compressor duty cycle?
If so, it could help explain some of the varied responses on how the system output is perceived.
That's certainly possible. My Fiat has an interior humidity sensor to maximize system efficiency without sacrificing passenger comfort and windshield visibility.

In my experience with the Passat and the Touareg, I don't think Volkwagen takes humidity into account as much as they could.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
Relative humidity often influences hot hot, or cold someone "feels".

If so, it could help explain some of the varied responses on how the system output is perceived.
Part of the cooling of the A/C is the dehumidification of the air. I think that if you are in hot HUMID place the A/C could feel extra cool since you are feeling relief from the humidity and getting say 45 degree air. If you are in a dry place like I am you would only feel the 45 degree air and no humidity relief. So that is another possible reason why people are perceiving different coolness of the A/C. I wonder though if the "cool" cars have not been emission fixed yet?
 
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