Aristo

Hi!

I didn't found any introduction thread, so I misuse this thread for a short description about myself.
I'm from Switzerland and one of the people which exported a Mustang to Europe (actually imported it
My Ride: 2010 Mustang GT, 19", manual, black. And I'm very proud of it!

Now to my problem with the TPMS system...

What I did:
I changed my factory rims (19" stock) to polished bullit rims (18"). Before I mounted the winter tires on the bullit's, I removed the old S197-TPMS sensors because I knew, that they won't work on a 2010.

What I expected:
Like the S197, I expected to press the reset button every time I start my car to get rid of the TPMS error message.

What the 2010 does:
Nothing! No light, no message, no sound. It's ok for me because:
- Europe car's don't need to have a TPMS-System
- I don't have to press the reset button every time I start my car

What makes me think of:
It looks like the TPMS system on my 2010 doesn't work at all. I really hope that this malfunction doesn't have any impact on other systems like for instance the stability control.

Now my questions to you: Does anyone of you experienced the same functionality already? Is it a failure? How was the behaviour of your 2010 models after switching to aftermarket wheels without sensors? I really appreciate any hints!

Thank you very much and have a good start into the week.

Regards,
Aristo

karrnutt

When I put on my 20"chrome razors without tps Nothing happened for a few kms but then the tps warning light flashed and the message center read tps error. I pressed reset and that took care of it till the next time I started it up and the sequence began again.

Aristo

Your right! After 300miles, my TPMS system began to blink while cruising on the highway and the tpms error appeared on the message center. Looks like it has some kind of lag...

Thx anyway

Regards
Aristo

Cusp

I think on the 2010s they went to Valve Stem sensors. I bet a tireshop could move them to the 18" wheels for you. I think I would have simply bought a set of sensors for the new wheels.

bob

They did, and its not much of a problem to move them over, IIRC it requires a torx20 or 21 bit and the special valvetstems and unless Ford has changed the way the system operates, sensor position is irrelavent (which is kinda sad because it would be nice to know which tire was going down when they trigger an alert).

The sensors also feature the ability to read air temps inside the tire as well, which is kinda neat if your a racer I guess?

Dixie_Flatline

Hardly just for racers. It's amazing how many people don't know that air pressure changes in an enclosed space (like a sealed tire) when temperature changes.

The tire pressure spec inside the door jamb is a cold rating. It depends on the tire, but generally when the tire is warm the same volume of air changes in density and the air pressure goes up when the tire gets warm. That doesn't mean you should remove air, it's just the air pressure of hot air is higher than the same volume of air when it is cold.

For the 235/55R17 Pirelli Pzero Nero's that came on my '08 Mustang GT, 32 psi cold is about 35 psi after being driven. Of course if you're in a really hot environment, that changes too. Winter vs. summer, et cetera.


Man, that new valve stem sensor system sounds nice, would probably alleviate a lot of rumpled feathers on people who have to pay a lot to change over the banded sensors.

bob

The banded sensors can read temp as well, but you need a TPMS tool to access either I suppose the real reason is to accurately calculate a low pressure condition irregardless of temp. All the same, it would be nice if the TPMS system in the Mustang could give position and relative pressure so that when you filled them no matter what the temp, you could jot down the pressures and add or subtract as needed. That'd be so much better than standing outside on a really cold morning with pen, paper and air guage before you start your day. The only downside would be when you rotate or have new tires installed (the latter isn't a big issue if the tech puts the new tires back in the original position), some sensors need to be calibrated to the new postion while others will auto learn.

Yeah, its a pretty good idea, not only because it eliminates the band clamps but also sensors attatched to the wheel with a nut tend to loosen up over time and occassionaly leak. The rubber stem sensor cures all that.

nonsensez9

with many tire shops and dealers filling with nitrogen now, should one add a couple pounds because nitrogen doesn't expand or contract much?

CO_VaporGT_09

Ideal gas law, p*v = n*R*T.

R nitrogen = 1775, R air = 1716

http://www.engineeringtoolbox.com/in...ant-d_588.html

http://www.science.uwaterloo.ca/~cch.../idealgas.html

So, no, not that big of a difference air to N2.

cdynaco

That's why I always check air pressure before I drive away from the house. But more than that, I have to check before the sun hits the tires. I'm in the forest and so when the sun hits the clear path to the car, one side will have sun and one side is still in shade. Direct sun will add up to 2# higher than the shady side.

bob

Yeah what CO said, the biggest difference between regular ol' air and nitrogen is the lack of moisture when you fill the tire (which may or may not be a problem depending on location and time of year).

CO_VaporGT_09

Yep, water vapor is the culprit. But most air tanks at tire shops have dryers built into them, so shouldn't be too much of a difference air to N2. Your home tank may be different, though, especially in more humid climates (We rarely break 35% humidity here on sunny days).


Gas Individual Gas Constant - R
Imperial Units SI Units Molecular Weight
(ft lb/slug oR) (J/kg K) (kg/kg mole)
Nitrogen, N2 1,775 296.8 28.02
Air 1,716 286.9 28.97
Water vapor 2,760 461.5 18.02



Anybody know if all Fords have gone to the stem sensor? I'm looking into a 2010 SHO, and when I search for winter wheels/tires on TireRack it shows the same bands and puck my Mustang has.

bob

You would be surprised, at near sea level in my AO, we have a compressor with the intake elevated out into cool fresh air (rather than the hot muggy air of the comressor room), auto-drains, splits in the piping to allow water to shear away from the flow of air, air/water seperators at the line ends, and a dryer installed and water still collects in the system occasionally.

CO_VaporGT_09

Man, I have a humidifier installed on my house AC/heater, cause it gets so dry the wood floors contract!