MK7 HVAC Aux heater

GreenLantern_TDI

Veteran Member
Joined
Feb 27, 2014
Location
Iowa
TDI
2015 GOLF SEL
I wonder if it would be possible to add an aux heater in the hvac similar to what the MK5s had. This would aid to defrost windows faster and get cabin heat faster in the winter. Thoughts?
 

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
I think it does?

I disabled it in vcds and it makes a huge difference.

Someone mentioned that's why our cars have a decent alternator is because of the aux heating grid...


Coolant has to be cool, heat maxed, and assuming a certain outdoor temp...

Conditions right i do hear a relay, lights dim, and ecm touches the rpm a bit, probably to help alternator move air over itself.


Sent from my 2PS64 using Tapatalk
 
Last edited:

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
I was curious of it's impact on performance.

Quite an impact. To be honest my experiment with it off, the engine actually took longer to heat up. I honestly think it helps the engine heat up more then the cabin with recirculation turned on!

I then checked the little box and reapplied.

It works.

You can enable and disable alot with vcds.

I want the diesel fired heater like the European cars.

Sent from my 2PS64 using Tapatalk
 
Last edited:

GreenLantern_TDI

Veteran Member
Joined
Feb 27, 2014
Location
Iowa
TDI
2015 GOLF SEL
Yes i want that diesel fired heater too. Like a webasto. All tdis should have this stock for colder climates anything from missouri north.
 

GreenLantern_TDI

Veteran Member
Joined
Feb 27, 2014
Location
Iowa
TDI
2015 GOLF SEL
I think it does?

I disabled it in vcds and it makes a huge difference.

Someone mentioned that's why our cars have a decent alternator is because of the aux heating grid...


Coolant has to be cool, heat maxed, and assuming a certain outdoor temp...

Conditions right i do hear a relay, lights dim, and ecm touches the rpm a bit, probably to help alternator move air over itself.


Sent from my 2PS64 using Tapatalk
Whats it called in VCDS?
 

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
Not sure.

It's a hassle to hook up laptop too. Screen gone all floppy and battery doesn't charge.

There's 2? options in the hvac long coding.

Should be on by default from factory.

One is the grid heater. The other is the wabeaxo tjinger. One should be enabled, other not.



Sent from my 2PS64 using Tapatalk
 

The Tortoise

Veteran Member
Joined
Apr 24, 2017
Location
Ottawa
TDI
2015 GSW Trendline - White
Same. (Canadian model)

That said, I have been impressed with how quickly my TDI makes heat. It's usually making decent heat in less than 5 minutes, and that's down to temps as low as -30C.
 

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
Very odd the northern cars do not have the aux heater. Pull a kick panel on drivers side, should see a serious copper lead going to the heater sandwiched to the heater core....

Sent from my 2PS64 using Tapatalk
 

The Tortoise

Veteran Member
Joined
Apr 24, 2017
Location
Ottawa
TDI
2015 GSW Trendline - White
I also have two 40 amp fuses next to each other in the fuse box. So, maybe I do have the heater? I just know that when I looked up the VIN there was no mention of it.

At least the Canadian cars get the coolant heater.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
2010 mk5 heater/relay had 100amp I think (100x12 = 1200w) you could also hear the chunky relay cycling at idle. Our '15 Passat has no audible relay clicking.

Also I have no idea why the would split the relay as 2x40A, that is just backwards.
 

GreenLantern_TDI

Veteran Member
Joined
Feb 27, 2014
Location
Iowa
TDI
2015 GOLF SEL
2010 mk5 heater/relay had 100amp I think (100x12 = 1200w) you could also hear the chunky relay cycling at idle. Our '15 Passat has no audible relay clicking.

Also I have no idea why the would split the relay as 2x40A, that is just backwards.
It could be a dual element. But either way i doubt the mk7s have them guess one of us should look and see...
 

Matt927

Veteran Member
Joined
Dec 29, 2013
Location
Northeast
TDI
several
They do not have them, at least the cars designated for the USA. It was deemed unnecessary with the different cooling system architecture. Essentially a micro circuit around the cylinder head to help bring the water temp up as quickly as possible for cabin heat. I specifically remember checking for this when I took delivery of a new 2015 Golf TDI in May 2015.

The Mk6 Golf TDIs make a distinctive click sound then their aux cabin heater energizes and I believe certain criteria has to be met: temperature control on high, fan on speed 2 or greater, coolant temperature threshold as well as system load.

It does seem the European Mk7 cars had the electric aux heater installed, or at least some of them.

Edit: Going back a few years, I found this from a previous thread on the topic. This was from the build sheet on my Mk7 Golf TDI:

7E0: W/o heat accumulator/auxiliary heating

Also of note, 9M0: Without auxiliary/parking heater
 
Last edited:

The Tortoise

Veteran Member
Joined
Apr 24, 2017
Location
Ottawa
TDI
2015 GSW Trendline - White
Mine is 7AU = Anti-theft alarm system, passenger compartment control, backup horn and towing protection
 

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
Hm. Mine has it. 2015 wagon. Under the certain conditions I can watch generator load ramp up tremendously. Fan speed set to 3, and maxing/not maxing the heat setting will trip the system and I can watch generator load on vcds spike up and down.

Tonight I'll try and get some screen shots of the bit code that enables and disables it. I got busy Lastnight.



Sent from my 2PS64 using Tapatalk
 
Last edited:

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
If it's like previous generations, the HVAC system will need the outside temps bellow a certain threshold, 50-55F I think before the grid heater kicked on.
 

tanker

Member
Joined
Mar 19, 2001
Location
Appleton, ON, Canada
TDI
2015 GSW TrendLine
Here's what my European copy of the manual says. I haven't checked my 15 to see if I have Module J604. It suggests an 80A heater vice the 100A in the Mk5.
4.13 Auxiliary Heater Heating Element - Z35-
with Auxiliary Air Heater Control Module
-J604- , Checking
Test Conditions
• The intake temperature is below 19 °C (66.2 °F)
• The coolant temperature is below 80 °C (176 °F)
• The passenger compartment temperature is approximately 20
°C (68 °F)
• Battery voltage greater than 11 V
• Alternator load not greater than 50% (terminal DF)
• Engine RPM higher than 450
• Turn the interior temperature control to maximum heating. (For
vehicles with Climatronic select the high setting).
Test Sequence
– Remove the left footwell center console trim.
measure the current draw on the Ground (GND) cable from
Auxiliary Heater Heating Element - Z35-
Slight heating output ≈ 30A
Medium heating output ≈ 60A
Large heating output ≈ 80A
 
Last edited:

PHAT-DUB

Vendor
Joined
Apr 30, 2006
Location
Markham
Has it been confirmed that US/Canada mk7s do not have a aux heater?

Sent from my ONEPLUS A6013 using Tapatalk
 

petee_c

Veteran Member
Joined
Jun 2, 2014
Location
Heidelberg, Ontario, Canada
TDI
15 Golf TDI, was 06 Jetta TDI, 15 q7 tdi, was 11 Q7 TDI
Has it been confirmed that US/Canada mk7s do not have a aux heater?

Sent from my ONEPLUS A6013 using Tapatalk
according to the VIN scan, my vcds scan, my 2015 Cdn Golf TDI did not come with the heater.... I am contemplating getting a used one, and installing it for next winter...

took about 7-9 minutes for the coolant temperature gauge to move in my car this morning when driving 80kph with ambient temperature at -16C... it was garaged and read -6C when I 1st started the car...
 

The Tortoise

Veteran Member
Joined
Apr 24, 2017
Location
Ottawa
TDI
2015 GSW Trendline - White
Has it been confirmed that US/Canada mk7s do not have a aux heater?
I'm now convinced mine does. Trendline GSW.

With the heat cranked it's blowing warm air about a minute. And looking up the VIN mine had the 7E6 listed.
 

pedroYUL

Veteran Member
Joined
Sep 8, 2011
Location
MI, USA
TDI
2015 Passat CVCA; 2015 GSW CRUA; 2012 wagon CJAA; 2004 wagon BEW
Reviving this old thread, so maybe I can contribute a little to this excellent site.

I started this week thinking my wife's mk7 GSW didn't have the electric aux heater installed, but I finally had a look where the heater goes and bingo, there is one there.

Then, I wanted to output test it like the heater in an mk5 jetta we used to own, and I couldn't make sense on where to look in VCDS.

Turns out, this electric heater is called PTC heater, and it does not have a controller (address) in VCDS, not an independent module, but a bit in address 08 (Auto HVAC) which determines if the heater is there and can be made to function:


I could only make sure the bit was correct in the coding of module 08, but there is no way to output test this heater. References to Aux Heater address 18 are actually for webasto heaters.
 
Last edited:

pedroYUL

Veteran Member
Joined
Sep 8, 2011
Location
MI, USA
TDI
2015 Passat CVCA; 2015 GSW CRUA; 2012 wagon CJAA; 2004 wagon BEW
These threads pointed me in the right direction, after reading quite a bit on Aux Heater address 18 and some other address which are both not applicable to our cars:


 

Cuzoe

Veteran Member
Joined
May 24, 2017
Location
Los Angeles
TDI
MK7 Golf S
For what it's worth, the build sheet for my Golf S has PR 7E6 - Electric Auxiliary Air Heater. Car is a Golf S, which also has PR 8Z6 - Hot Country and 0Y4 - Cold and Tropical Climatic Zones (US).
 

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
Canadian GSW (SEL/Highline) here. No extra heater listed . Oddly enough, even though the car has a factory-installed block heater, I don't see it in the PR-code list (unless it's included as part of "BOE = Component parts set complying with vehicle type for Canada various parts").
 
Last edited:

Cuzoe

Veteran Member
Joined
May 24, 2017
Location
Los Angeles
TDI
MK7 Golf S
They do not have them, at least the cars designated for the USA. It was deemed unnecessary with the different cooling system architecture. Essentially a micro circuit around the cylinder head to help bring the water temp up as quickly as possible for cabin heat. I specifically remember checking for this when I took delivery of a new 2015 Golf TDI in May 2015.

Edit: Going back a few years, I found this from a previous thread on the topic. This was from the build sheet on my Mk7 Golf TDI:

7E0: W/o heat accumulator/auxiliary heating

Also of note, 9M0: Without auxiliary/parking heater
My 2015 Golf S has the heater. Finally confirmed (with my eyes) 18 months after the last activity in this thread, haha. Anyway, previously I mentioned that my Golf has the following PR Codes, of interest here...

OY4 - Cold and Tropical Climatic Zones (US)
7E6 - Electric Auxiliary Air Heater
8Z6 - Hot Country
9M0 - Without Electric Auxiliary Heater / Fuel-fired Parking Heater
This is the interesting one, but maybe this is on the build sheet if either of these is not installed. Kind of silly, and I certainly don't have the fuel-fired webasto. The fuel-fired parking heater is PR code 9M1, or code 9M9 with remote control (this would be the retrofit to do, if you were doing it).
NY0 - Standard Battery/Alternator Capacity
It seems that whatever the current (as of 2015) standard capacity was, it was enough for cars equipped with Aux Heater
And for the curious, the other possibilities here... NY1 - Increased Battery/Alternator, NY2 - Increased Battery, NY3 - Increased Alternator, NY4 - AGM and Increased Alternator, NY5 - AGM and Standard Alternator

In fact, I was only verifying the Aux Heater in order to convince myself not to retrofit the webasto. I live in SoCal and do not have any real intention of moving anywhere colder. Being able to get warm air quickly in the cabin (from this Aux heater) would have been an easy retrofit to sell myself on but I don't need to pre-warm my coolant. At least not a cost of about $1,000 which is about what the webasto retrofit will cost (most of that is needing to import a diesel-using webasto unit). The ones for gassers are quite common, and can be had for under $250 while I can't find a diesel one for less than $800.

Anyway, my original HVAC unit, like @pedroYUL's was coded for the heater. I carried over that coding to my replacement HVAC when I added heated seats to the car. I'm soon to replace the HVAC panel again and figured I should know for sure whether that coding is right. As previously mentioned this Aux Heater (unlike the fuel-fired webasto) has no discrete control unit so I'm not sure you would get a fault by having it coded (and not installed). Possibly HVAC would throw a fault, which is an easy thing to check, that I probably won't be bothered to check.

A question for @Nuje and others (with block heater). When you use the block heater is it a correct assumption that you get warm air in the cabin pretty quickly once you're on the road? Could that be reason your (Nuje's) car does not have the auxiliary heater? Not that it couldn't have both, but VW (like most companies) is not going to spend money they feel can be saved on overlapping function. My un-substantiated guess is the webasto is more expensive (overall) than the block heater which is why we don't have it at all.

Oh yea, pictures...
https://flic.kr/p/2p2invL https://flic.kr/p/2p2invF
Also very unrelated but something I noticed looking at my build sheet... PR Code GM1 - Standard Electronic Engine Sound
Anybody know what this might be?
 

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
Well, I won't be of much help as I have yet to make use of the block heater. West coast doesn't get "real" winter (brutal cold here is -10°C....and that's maybe two nights per year). Between heated seats, heated steering wheel, and the (troublesome for some) shroud over the water pump that limits circulation when cold, I've found even near freezing temps, I have heat* within a couple km so don't really feel the need.
(*Heat = warmer than ambient air; within 7km when I get to the freeway, it's definitely legit comfy/warm.)
 
Top