39* Degree Outside Temp Warning

whiplash willy

Veteran Member
Joined
Aug 1, 2011
Location
Portland Oregon
TDI
2012 4-Door Golf TDI 6MT w/NAV & Sunroof
Does anyone know how to disable that annoying 39* Degree Outside Temp Warning that automatically comes up when it is below 40* F? (With Vag-Com)

I hate how it always pops up on the MFD screen, and switches the display from whatever it was on.
 

pdt165

Veteran Member
Joined
Jul 28, 2011
Location
Fl
TDI
2011 Jetta 6 speed (Bought Back)
Does anyone know how to disable that annoying 39* Degree Outside Temp Warning that automatically comes up when it is below 40* F? (With Vag-Com)

I hate how it always pops up on the MFD screen, and switches the display from whatever it was on.
What is the purpose of said warning?
 

JSWTDI09

Top Post Dawg
Joined
Jan 31, 2009
Location
Las Vegas, Nevada
TDI
2009 JSW TDI (gone but not forgotten)
What is the purpose of said warning?
It is to warn you of the possibility of "black ice" formation. I have no idea why they chose 39 degrees to be the warning level.

Have Fun!

Don

P.S. I, too, would be interested to know if this can be turned off. I live somewhere 39 degrees is common (in the winter) but freezing is rare.
 

jbright

Veteran Member
Joined
Sep 10, 2009
Location
Indianapolis
TDI
2009 Jetta DSG
Might be alerting us to the possibility of ice formation on bridges and overpasses, etc. which can ice up earlier than regular road surfaces (even if the air temperature is above freezing).
 
Last edited:

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
Might be alerting us to the possibility of ice formation on bridges and overpasses, etc. which can ice up earlier than regular road surfaces (even if the air temperature is above freezing).
If the air temp drops from 45F down to 39F, no ice is going to form anywhere, bridge or otherwise. The bridge superstructure will only be as cold as ambient.

I'm sure someone will chime in with "supercooling", but that's not likely to happen either.
 

Engineers<3Diesel

Veteran Member
Joined
Oct 7, 2011
Location
North Carolina
TDI
2012 VW Jetta TDI
Ok I won't use the term supercooling. Ice can form on bridges even when the outside temp is above 32F. This is due to air flow under the bridge and pressure drops that can occur (change in pressure = change in temperature).

A good example of this is on my 70 air cooled VW beetle intake manifold. Even when it is 80 degrees outside, the pressure drop causes temps to lower and gas to drop out of suspension in the air. Also deemed a "frozen intake" they can get down to 40-50 degrees in the summer which is why tubes were put in later models to pull off exhaust gas and run it through tubes welded to the intake. This helped keep them warm and prevent the gas from "freezing".
 

MN_TDI12

Veteran Member
Joined
Sep 12, 2011
Location
Triad, NC
TDI
2012 Jetta TDI DSG w/Nav
I was thinking about posting this exact same question. What I find annoy the most is that it take over your mini MFD but doesn't reset back to the info position that you had it on so you have to click back thru.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
If the air temp drops from 45F down to 39F, no ice is going to form anywhere, bridge or otherwise. The bridge superstructure will only be as cold as ambient.

I'm sure someone will chime in with "supercooling", but that's not likely to happen either.

Yeah but what about when the temp goes from 0F in the morning to 39F in the afternoon you still think there may be some ice on the roads?
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
Yeah but what about when the temp goes from 0F in the morning to 39F in the afternoon you still think there may be some ice on the roads?
That's a different story. If it's 0F when I wake up tomorrow and warms to the 30s, I'll be expecting ice. Unfortunately the MFA isn't smart enough to know when it makes sense to warn the driver or not. If I wake up tomorrow and it's 39F and stays 39F all day, I'm still not going to worry about ice on any of the many bridges I cross during the day.

I just think the warning is stupid. I don't mind the snow flake so much, but the chime is annoying. VWs chime for everything: low fuel, low windshield washer fluid. I know American society has been dumbed-down overt the last few generations--hence only 1 in 6 Americans being able to drive a manual transmission. Why not chime when humidity rises in the cabin and condensation is likely to form on the inside of the glass? Or when it's hot outside and you shouldn't leave your dog in the car with the windows up?
 
Last edited:

elconquistador

Veteran Member
Joined
Mar 29, 2011
Location
St. Peters, MO
TDI
2011 Jetta TDI
I know American society has been dumbed-down overt the last few generations--hence only 1 in 6 Americans being able to drive a manual transmission.
LOL that's kind of a jump there, because most cars driven on the road today are Auto. There is a difference between "dumbed-down" and "ignorant" of something. ;)
 

DuvalSt

Active member
Joined
Aug 20, 2011
Location
Columbus, OH
TDI
2011 Jetta TDI DSG
That's a different story. If it's 0F when I wake up tomorrow and warms to the 30s, I'll be expecting ice. Unfortunately the MFA isn't smart enough to know when it makes sense to warn the driver or not. If I wake up tomorrow and it's 39F and stays 39F all day, I'm still not going to worry about ice on any of the many bridges I cross during the day.

I just think the warning is stupid. I don't mind the snow flake so much, but the chime is annoying. VWs chime for everything: low fuel, low windshield washer fluid. I know American society has been dumbed-down overt the last few generations--hence only 1 in 6 Americans being able to drive a manual transmission. Why not chime when humidity rises in the cabin and condensation is likely to form on the inside of the glass? Or when it's hot outside and you shouldn't leave your dog in the car with the windows up?
I believe historically Volkswagen has sold and is still selling more manual transmissions than automatics. Probably the only manufacture (maybe other than BMW and Porsche) doing so. Of the 13 VW's I've owned, only 2 were automatics and that's because my new wife of 10 years claims she use to drive with 3 on the tree, but can't drive with 4 (or more) on the floor. Go figure. As for leaving the dog in the car when it's hot, break a window out first, then call the police. As for the chime, turn up the radio.
 

pdt165

Veteran Member
Joined
Jul 28, 2011
Location
Fl
TDI
2011 Jetta 6 speed (Bought Back)
I believe historically Volkswagen has sold and is still selling more manual transmissions than automatics. Probably the only manufacture (maybe other than BMW and Porsche) doing so. Of the 13 VW's I've owned, only 2 were automatics and that's because my new wife of 10 years claims she use to drive with 3 on the tree, but can't drive with 4 (or more) on the floor. Go figure. As for leaving the dog in the car when it's hot, break a window out first, then call the police. As for the chime, turn up the radio.
One of my main requirements when buying my new car was a manual trans. I hadnt had one in over 6 years and missed it. Out of VW toyota, honda and nissian it was VW that had more than 1 one the lot, and only honda had base line accords, not worth it at all.
 

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
If the air temp drops from 45F down to 39F, no ice is going to form anywhere, bridge or otherwise. The bridge superstructure will only be as cold as ambient.
This is not true, for a couple of reasons.

1. If it is nighttime, and there is a clear sky, heat will radiate from all surfaces to the sky and cause those surfaces to drop below ambient temperature. This is the manner in which frost (ice) forms on ALL surfaces when it is just above freezing overnight. Frost will form preferentially on surfaces that have direct exposure to the night sky.

2. The air temperature that the vehicle's ambient temperature sensor is seeing, isn't necessarily the same as the instantaneous outside temperature. If you drive into a valley in early morning, and it has been a still, cloudless night, it is very common for that valley to be several degrees colder than the surrounding higher ground.
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
This question comes up every fall. I'm going to give up beating this dead horse. I won't worry about ice forming when it's 39f tomorrow.
 
Last edited:

JSWTDI09

Top Post Dawg
Joined
Jan 31, 2009
Location
Las Vegas, Nevada
TDI
2009 JSW TDI (gone but not forgotten)
Since this thread seems to have drifted into a discussion of whether or not ice can form at 39 degrees F, instead of whether or not this warning can be disabled, I will assume that nobody knows the answer to the OP's actual question. Therefore, my suggestion would be to ask the original question again in the OBDII forum where the Ross-Tech guys are more likely to see it and reply. I personally do not care why VW chose the 39 degree point to give us this warning, but I would love to turn it off.

Have Fun!

Don
 

EnigmaMan

Well-known member
Joined
Oct 8, 2011
Location
West Palm Beach, FL
TDI
2011 Jetta
Even when it is 80 degrees outside, the pressure drop causes temps to lower and gas to drop out of suspension in the air. Also deemed a "frozen intake" they can get down to 40-50 degrees in the summer which is why tubes were put in later models to pull off exhaust gas and run it through tubes welded to the intake. This helped keep them warm and prevent the gas from "freezing".
Tell me more about this, I would like to do this on my 7.5L 468ci Big block. I would love to super cool the air going into the intake with out using a 225+ shot of NOx.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Tell me more about this, I would like to do this on my 7.5L 468ci Big block. I would love to super cool the air going into the intake with out using a 225+ shot of NOx.

comparing the air intake of a 1600CC air cooled flat 4 to a 7.5L V8 isn't quite the same ball park.
 

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
I didn't see anything in the long coding in VAG-COM on the temperature warning, but I wasn't really looking for it, either. I will check next time I'm in there.

Regarding manual versus automatics, VW, I'm sure, like everyone else, sells many more automatic transmission cars than manuals. Just walk around a dealer lot and see how few cars are there with manual transmissions. I was at a local dealer recently and there were 6 TDIs on the lot, all DSG. This is typical. And 5 new Passats (gas and diesel) no manual.

Outside people in this community I know very few adults that can drive manual transmission cars. And I've had kids in my car that don't even know what the clutch pedal is. They're amused by that until distracted by the crank windows. That's a real oddity these days.
 

> Luke <

Veteran Member
Joined
Jun 16, 2011
Location
West Los Angeles
TDI
Golf 2011 TDi DSG
What I find annoy the most is that it take over your mini MFD but doesn't reset back to the info position that you had it on so you have to click back thru.
After about 10>20 seconds, mine does reset to original screen.....
 

JSWTDI09

Top Post Dawg
Joined
Jan 31, 2009
Location
Las Vegas, Nevada
TDI
2009 JSW TDI (gone but not forgotten)
After about 10>20 seconds, mine does reset to original screen.....
I believe that it will reset immediately if (when) you acknowledge it by pressing the OK button on your steering wheel or stalk. However, I would still like to see it gone completely.

Have Fun!

Don
 

dweisel

Top Post Dawg
Joined
Jul 28, 2006
Location
Wheeling, West Virginia
TDI
dweisel isn't diesel anymore!
I personally do not care why VW chose the 39 degree point to give us this warning, but I would love to turn it off.

Have Fun!

Don
Because if the warning went off at 32 degree's it would be too late. I would agree though that almost everyone hates it.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
True, but the physics should be the same... More air = more cooling power :D

but the size of the intakes for the 1.6L vs 7.5L have got to be different, smaller the intake with a higher velocity the greater the differential pressure. The 7.5 intake's probably huge because it needs flows more so the velocity is probably at lot less.
 

TDI-Photog

Veteran Member
Joined
Aug 21, 2011
Location
Minneapolis
TDI
2011 Jetta TDI 6m
It is to warn you of the possibility of "black ice" formation. I have no idea why they chose 39 degrees to be the warning level.

Have Fun!

Don

P.S. I, too, would be interested to know if this can be turned off. I live somewhere 39 degrees is common (in the winter) but freezing is rare.
I think it is set to 39F because in the morning, the air temp can be that warm but the road surface can still be at or below freezing.
 

TDI-Photog

Veteran Member
Joined
Aug 21, 2011
Location
Minneapolis
TDI
2011 Jetta TDI 6m
If the air temp drops from 45F down to 39F, no ice is going to form anywhere, bridge or otherwise. The bridge superstructure will only be as cold as ambient.

I'm sure someone will chime in with "supercooling", but that's not likely to happen either.
I think it has more to do with the air temp rising faster than road temp (like in the morning after a freeze).
 
Top