Auxiliary heater?

Jibeho · Dec 5, 2008

I know my 2009 has one of these because the other day when it was 42 I got instant warm air just after start. I did notice that my instant mileage readout was taking a hit, so I turned off the heat and it came back up. I think I read somewhere that this heater is 1000 watts. If you do the math that is about 80 amps! I guess that us a sizable pull on the alternator.

mdfirefighter · Dec 5, 2008

awesome, thanks for the update.

hid3 · Dec 5, 2008

I don't get, what's the original question? When you turn your A/C on, that also consumes fuel; that's simple physics - the power neither comes from nowhere neither disappears to nowhere just one sort of power turns into another.

wesk1954 · Dec 5, 2008

I agree the aux heater is a HUGE bonus for those of us living in balmy Cleveland, OH.. Man I'm LOVING IT. And yes, I've taken about a 2 mpg mileage hit so far this winter - it takes 20 minutes for the car to get up to temp and in that time it uses a LOT LOT LOT more fuel... plus as you say, perhaps the heater amp drain reduces the mileage a bit, but besides not being something we can control, it is a HUGE benefit in my opinion. Can't believe the owner's manual doesn't even mention it... to me this is a major selling point in cold climates.

Wes

maloosheck · Dec 5, 2008

Here is your victim:

Connected with two finger-thick wires bolted to it and CAN-BUS:

MBoni · Dec 5, 2008

If you look in your fuse box under the hood, you'll see a huge honkin' 100A fuse for the heater.

But between that and the heated seats, a cold morning commute is much nicer than it might have been.

wesk1954 · Dec 5, 2008

Maloosheck.. thank's so much for the pics... this absoutely CONFIRMS the existence of an aux heater!

Wes

Jibeho · Dec 5, 2008

Thanks also for the Pix. Is 1000 watts correct? I would imagin it would not be much more with that 100a fuse.

wesk1954 · Dec 5, 2008

Watts divided by volts equal amps... so, 1000/12=83.3 amps.... my guess is that 1000 watts is correct.

Wes

hid3 · Dec 5, 2008

maloosheck said:
Here is your victim:

maloosheck, since you have '06, how do you know when the heater is activated? I have selected the bit 0 (aux heat. installed) under Central electronics but can't access the module directly from the main screen (18 Aux. heater). So now I wonder if I have the heater or not. Autoscan shows the heater element and doesn't throw any error codes.

maloosheck · Dec 5, 2008

Because you are trying to reach wrong Aux. Heater. 18 Aux. Heater is Webasto, PTC (the one discussed here) is under different address (7x, do not remember). Check autoscan for the number.

hid3 · Dec 5, 2008

Code:

Address 7D: Aux. Heat
   Part No SW: 1K0 963 235 E    HW: 1K0 963 235 E
   Component: PTC-Element         0404
No fault code found.
End

Ouch, it's 7D. Will try to access it.

redbrick1 · Dec 5, 2008

wesk1954 said:
I agree the aux heater is a HUGE bonus for those of us living in balmy Cleveland, OH.. Man I'm LOVING IT. And yes, I've taken about a 2 mpg mileage hit so far this winter - it takes 20 minutes for the car to get up to temp and in that time it uses a LOT LOT LOT more fuel... plus as you say, perhaps the heater amp drain reduces the mileage a bit, but besides not being something we can control, it is a HUGE benefit in my opinion. Can't believe the owner's manual doesn't even mention it... to me this is a major selling point in cold climates.

Wes

I agree, until the car gets up to full operating temps the mileage is way down. My in town mpg, when cold is low 20s. Once fully warmed up, I can easily go over 30 mpg. These numbers are from the last week when its been between +4 and +20 F in the AM. I'm curious if they'll be lower still if it's below zero.

wesk1954 · Dec 5, 2008

I'm going to guess the lower the temps, the lower the mileage for two reasons... one is the fuel mixture to keep it from gelling... the more #1, the lower the combustion rate, and the other more realistic issue is it will take that much longer for the car to reach normal operating temps.

Wes

Tim Birney · Dec 5, 2008

wesk1954 said:
I'm going to guess the lower the temps, the lower the mileage for two reasons... one is the fuel mixture to keep it from gelling... the more #1, the lower the combustion rate, and the other more realistic issue is it will take that much longer for the car to reach normal operating temps.

Wes

100% correct.
My short daily commute (8 miles) does not allow for full engine warmup.
Yet if I take a highway trip on the Weekend, I will get back to normal Highway MPGs. (or very close to normal...)

Fumes · Dec 7, 2008

Boy it sure would be nice if there was a retrofit for Mk4s. But would be quite involved with that high of a draw.

barshnik · Dec 16, 2008

maloosheck said:
Here is your victim:

Connected with two finger-thick wires bolted to it and CAN-BUS:

Where is this located, exactly? Thanks,

John F

TDIMOFO · Dec 16, 2008

Just to be absolutely clear.
My car when cold will produce HOT air through the use of an electrical heater?
Is this correct?
Is this stock?
I have a new 2009 Jetta TDI.
I suspect that auto manufactures would like to go to an all electric system for both heat and air conditioning.
They have made the power steering electric... what is next?
Thank you.
TDIMOFO

Lightflyer1 · Dec 16, 2008

Check post 12 for how to check for heater. If you have it, it will produce some heat (not blazing hot) early on until the car warms up. I presume they all come stock with one.

jvance · Dec 16, 2008

TDIMOFO said:
Just to be absolutely clear.
My car when cold will produce HOT air through the use of an electrical heater?
Is this correct?
Is this stock?
I have a new 2009 Jetta TDI.
I suspect that auto manufactures would like to go to an all electric system for both heat and air conditioning.
They have made the power steering electric... what is next?
Thank you.
TDIMOFO

Yep. Warm air within seconds.

maloosheck · Dec 16, 2008

barshnik said:
Where is this located, exactly?

Inside the airbox, in front of the heater core. I will try to take some more pictures of this thing inside the car, I still have some of my interior trim panels off.

TDIMOFO · Dec 16, 2008

jvance said:
Yep. Warm air within seconds.

Thank you.
Very cool feature. I have never heard of this and it really is an obvious advanvement....
TDIMOFO

r322tdi · Dec 16, 2008

Is there any special way to turn this on or is it automatic?

I don't feel the heat

such as
heat dial maxed
fan set at x

2footbraker · Dec 16, 2008

On package 0 2006 you just turn the temp dial up and turn off economy mode.

jvance · Dec 16, 2008

r322tdi said:
Is there any special way to turn this on or is it automatic?

I don't feel the heat

such as
heat dial maxed
fan set at x

On mine, not really.

You should hear a relay clicking on and off somewhere in the left dash.

darrenf · Dec 17, 2008

jvance said:
You should hear a relay clicking on and off somewhere in the left dash.

This relay seems to turn on the heat only when the engine RPMs are sufficient to generate the needed current.

r322tdi, set the heat on full, the fan on 2 (or whatever) and then get on the road. As soon as the engine RPMs bump up from idle it will turn the heater on. If it's sitting in your driveway then it probably won't switch on.

-darren

abarns · Dec 17, 2008

It's worth noting that the air from the aux heater will be warmer than the air in the car, but going as far as to say that it is 'hot' or even 'warm' may be going too far... it's enough to take the edge off but it's not anywhere close to the heat you'll get once your engine warms up. Definately a worthwhile addition to the car, though.

maloosheck · Dec 17, 2008

I was checking out measuring blocks on PTC and it is not ON/OFF. On idle output was about 500W and it was higher while driving. But it all depends on the temp requested and temp of the air.

Bear in mind that the PTC is controlled over CAN-BUS and it interprets requests from Climatic/Climatronic.

Just set the temp to MAX and vent speed to medium and check if the heat is there. If not, use vag-com to check out PTC measuring blocks. There is a bit in CECM that enables/disables PTC and maybe it is not enabled.

airwolf · Dec 17, 2008

maloosheck said:
I was checking out measuring blocks on PTC and it is not ON/OFF. On idle output was about 500W and it was higher while driving. But it all depends on the temp requested and temp of the air.

Bear in mind that the PTC is controlled over CAN-BUS and it interprets requests from Climatic/Climatronic.

Just set the temp to MAX and vent speed to medium and check if the heat is there. If not, use vag-com to check out PTC measuring blocks. There is a bit in CECM that enables/disables PTC and maybe it is not enabled.

Where in VCDS where you to look at this info? I found it once, but cannot seem to locate it again.

maloosheck · Dec 17, 2008

For output info: 7D Aux. Heater -> Measuring blocks
For enabling bit: 09 Cent. Elec. -> Coding -> Long Coding -> Byte 4 Bit 0 or 1 (I believe 0 is for Webasto, 1 is for PTC, but do not quote me on that).

There is one more misleading info: there are bits in CECM that suggest that they need to be enabled in order to make some device work while in fact they do not have to. I have to double check but my Aux Heating bit was cleared and I still have instant heat. Same with e.g. memory seats (byte 4 bit 3): I was told by Sebastian (Ross-Tech) that this bit is completely ignored.

Auxiliary heater?

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