Silly questions re TPMS

tranquility · 11-13-2020, 09:14 AM

I never bothered asking, but how does ours work and where are they located? Do the shops changing my tires know to put them back when fitting new tires? Is it possible for them to forget to put back the relevant parts and if so will the system give a warning that the parts are missing and can no longer compute tire pressure? Tx.

KennyP · 11-13-2020, 10:18 AM

There are no sensors in the wheels. Flat tire is confirmed by measuring the rolling diameter of the wheel.

Quote:

. The Flat Tire Monitor (FTM) system uses the ABS to measure each tire's rolling radius changes and with it, the rotational speed of the wheels. Changes are detected and signaled as a flat tire.

It should work with any wheel set. Just have to reset them on idrive menu.

paris1 · 11-13-2020, 11:04 AM

Whoa, whoa, whoa! Back the truck up KennyP! Where did you get that? BMW uses wheel sensors in most (if not all) of their vehicles and certainly in the E89 (unless they did something different on EU cars). All you have to do is look at the valve stem to see the lock nut on the outside that secures the metal sensor to the rim. The type of TPMS system you're referring to (commonly used by Mazda until recently) uses a conventional rubber valve stem and rotational sensors located behind each wheel. As for the OP's question about a tire shop not knowing how to handle these components when changing tires, not likely!

tranquility · 11-13-2020, 11:41 AM

Ok, so the shops should know what they're doing. What does the locking nut look like? I haven't really taken a look at them vs a reg valve stem. Also, if they were removed, my system would tell me there's an error, right? Tx.

paris1 · 11-13-2020, 03:08 PM

Yes, of course the system would signal a missing sensor. You may be overthinking this! Just look at the valve stem on one of the wheels. It will look like this:

tranquility · 11-14-2020, 02:23 PM

Quote:

Originally Posted by paris1

Yes, of course the system would signal a missing sensor. You may be overthinking this! Just look at the valve stem on one of the wheels. It will look like this:

Ok, I'm confused cuz I think we have the same car, below is 2 of my summers and 2 winters (pls excuse the dirtiness). There is no nut there just a smooth rubber stem...the shops wouldn't steal them would they? I didn't get any error msgs so no idea. A few years ago it did work as I had a flat and the car alerted me but dunno if anything changed afterwards. Could it be another tpms type? Tbh, I don't remember what my stems look like when I first got my car if they had that nut thing there or not.

Another silly question, so since are attached to the valve stem, only 1 set of tires (either summer or winter) will be equipped w tpms then and the other not? If that's the case, shouldn't my car be ringing a warning when I switched to the other set? Or maybe when I bought my original winter tire pkg at the dealership they were already equipped with its dedicated tpms, in addition to the one that came w the car?

paris1 · 11-14-2020, 03:51 PM

OK, according to this thread
https://www.2addicts.com/forums/show....php?t=1130800
all (some?) Canadian market Z4s have an FTM (flat tire monitor) system rather than TMPS as on US cars. That would explain your rubber valve stems.

tranquility · 11-14-2020, 04:16 PM

Quote:

Originally Posted by paris1

OK, according to this thread
https://www.2addicts.com/forums/show....php?t=1130800
all (some?) Canadian market Z4s have an FTM (flat tire monitor) system rather than TMPS as on US cars. That would explain your rubber valve stems.

TX for clarification and peace of mind! So my next questions are which is better, why the different sys and what does BMW use now?

KennyP · 11-15-2020, 11:01 AM

Quote:

Originally Posted by paris1

Whoa, whoa, whoa! Back the truck up KennyP! Where did you get that? BMW uses wheel sensors in most (if not all) of their vehicles and certainly in the E89 (unless they did something different on EU cars). All you have to do is look at the valve stem to see the lock nut on the outside that secures the metal sensor to the rim. The type of TPMS system you're referring to (commonly used by Mazda until recently) uses a conventional rubber valve stem and rotational sensors located behind each wheel. As for the OP's question about a tire shop not knowing how to handle these components when changing tires, not likely!

I was not aware of any differences between regions. My 09 has rubber stems and no TPMS. Only FTM as i described above. Maybe TPMS is mandatory in the states?Maybe the system was changed on later cars like 2013 etc(with LCI) ? When i got the car i at first thought it had sensors in the wheels aswell, but was quickly educated on the matter by shop technicians.
TPMS is better, if you can see your pressures inside a car, for sure. FTM needs a large pressure drop to start notifying about flat tire. I have had it happen once and my tire was around 1 bar less than it should have been. When going from 2.9bar to 2.4bar in the rear tires i get no warning and have to manually check. I have Michelin electronic pressure gauge for that in the glovebox.

paris1 · 11-15-2020, 11:34 AM

Quote:

Originally Posted by KennyP

I was not aware of any differences between regions. My 09 has rubber stems and no TPMS. Only FTM as i described above. Maybe TPMS is mandatory in the states?Maybe the system was changed on later cars like 2013 etc(with LCI) ? When i got the car i at first thought it had sensors in the wheels aswell, but was quickly educated on the matter by shop technicians.
TPMS is better, if you can see your pressures inside a car, for sure. FTM needs a large pressure drop to start notifying about flat tire. I have had it happen once and my tire was around 1 bar less than it should have been. When going from 2.9bar to 2.4bar in the rear tires i get no warning and have to manually check. I have Michelin electronic pressure gauge for that in the glovebox.

In the US, manufacturers generally don't differentiate between TPMS and FTM style systems. They're all called TPMS. I suspect the reasons they use one or the other in different markets has to do with local regulations and/or cost. We all learned something today!

tranquility · 11-15-2020, 12:27 PM

Tx guys for the info. My memory's bad but I now kinda remember BMW allegedly didn't want to get blamed(potentially sued?) if the tpms gave out inaccurate readings so they supposedly wimped out and went w this simpler but less detailed FTM sys...who knows the real reason? I dunno what's the status quo now.

11-13-2020, 09:14 AM	#1
tranquility sportscars only 3236 Rep 3,193 Posts Drives: 2011 Z4 sDrive 35i Join Date: Aug 2007 Location: Montréal iTrader: (0)	Silly questions re TPMS I never bothered asking, but how does ours work and where are they located? Do the shops changing my tires know to put them back when fitting new tires? Is it possible for them to forget to put back the relevant parts and if so will the system give a warning that the parts are missing and can no longer compute tire pressure? Tx.
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11-13-2020, 11:04 AM	#3
paris1 Captain 90 Rep 745 Posts Drives: 2013 35i Space Grey over Coral Join Date: Oct 2014 Location: Northern Calif. iTrader: (0)	Whoa, whoa, whoa! Back the truck up KennyP! Where did you get that? BMW uses wheel sensors in most (if not all) of their vehicles and certainly in the E89 (unless they did something different on EU cars). All you have to do is look at the valve stem to see the lock nut on the outside that secures the metal sensor to the rim. The type of TPMS system you're referring to (commonly used by Mazda until recently) uses a conventional rubber valve stem and rotational sensors located behind each wheel. As for the OP's question about a tire shop not knowing how to handle these components when changing tires, not likely!
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11-13-2020, 11:41 AM	#4
tranquility sportscars only 3236 Rep 3,193 Posts Drives: 2011 Z4 sDrive 35i Join Date: Aug 2007 Location: Montréal iTrader: (0)	Ok, so the shops should know what they're doing. What does the locking nut look like? I haven't really taken a look at them vs a reg valve stem. Also, if they were removed, my system would tell me there's an error, right? Tx.
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11-13-2020, 03:08 PM	#5
paris1 Captain 90 Rep 745 Posts Drives: 2013 35i Space Grey over Coral Join Date: Oct 2014 Location: Northern Calif. iTrader: (0)	Yes, of course the system would signal a missing sensor. You may be overthinking this! Just look at the valve stem on one of the wheels. It will look like this: Attached Images
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11-14-2020, 03:51 PM	#7
paris1 Captain 90 Rep 745 Posts Drives: 2013 35i Space Grey over Coral Join Date: Oct 2014 Location: Northern Calif. iTrader: (0)	OK, according to this thread https://www.2addicts.com/forums/show....php?t=1130800 all (some?) Canadian market Z4s have an FTM (flat tire monitor) system rather than TMPS as on US cars. That would explain your rubber valve stems.
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11-15-2020, 12:27 PM	#11
tranquility sportscars only 3236 Rep 3,193 Posts Drives: 2011 Z4 sDrive 35i Join Date: Aug 2007 Location: Montréal iTrader: (0)	Tx guys for the info. My memory's bad but I now kinda remember BMW allegedly didn't want to get blamed(potentially sued?) if the tpms gave out inaccurate readings so they supposedly wimped out and went w this simpler but less detailed FTM sys...who knows the real reason? I dunno what's the status quo now.
	Appreciate 0 Quote