Tpms

bradrhale · 11-30-2008, 01:21 PM

how does the computer know when the wheels have been rotated if the sensor is part of the valve stem?? it has to know somehow since i have rotated them and it still reads accurate.

leolkfrm · 11-30-2008, 01:27 PM

last time i asked at the tire dealer they told me it was pressure only on most vehicles, they have to rebuild and reset them when changing tires. I'm glad i don't have them

bradrhale · 11-30-2008, 02:26 PM

thats fine about reseting them and all but how does it know when i put move a rear tire up front?? somehow it knows since it reads correct when a tire is a little low. and i mean that literally as the beeper comes on when a tire has 26 psi in it. very sensitive.

gmctrucks · 11-30-2008, 02:44 PM

I don't know. But my buddy next door was working on a Mercedes well the drivers window switch went out so he removed the one from the passenger door and placed it on the drivers door well the passenger window would open up even if it was connected to the drivers window wiring harness.

mudseeker · 11-30-2008, 02:50 PM

maybe it's like a wireless wheel speed sensor. the valve stem could just be one half of the sensor. there may be another part of the sensor mounted on the hub. i'll ask my instructor tomorrow for you.

FaselZ71 · 11-30-2008, 05:47 PM

Maybe it's something simple like magnetic signatures and magnetic recepters in the hubs... or something crazy like that...

gmctrucks · 11-30-2008, 06:38 PM

Each tire & wheel well has a sensor so when changed it re-sets them. It's kinda like the FLUX CAPACITOR that's on the back to the future car. For real.

87c10slammer · 11-30-2008, 07:46 PM

i think it reads it from the direction its coming from.. like there is a sender inside the rim and a reciever inside that wheelwell... they all should be on the same frequancy so you could mount them upsidedown and backwards and it would still tell you the right from the left

mudseeker · 11-30-2008, 08:06 PM

apparently there are 2 types of monitoring systems.

from WIKI:

In order to transfer data from a rotating wheel, Direct Sensor TPMS may use a Radio Frequency (RF) communication channel or an electromagnetic coupling means to overcome the tire/chassis rotational boundary.

Indirect TPMS are realized in software in combination with wheel speed sensors for anti-lock braking systems, and electronic stability control systems. A disadvantage of indirect TPMS is that the driver must calibrate the system by pushing a reset button on the dashboard or through the on-board computer and if this is performed when any tire is in an underinflated condition then the system will not report correctly.

87c10slammer · 11-30-2008, 08:11 PM

i like the first better... basically it has a set inflation pressure so you cant have 4 different tires of different pressures and think that there all normal

11-30-2008, 01:21 PM	#1
bradrhale Senior Moderator Join Date: Apr 2006 Location: Texas Posts: 9,547	Tpms how does the computer know when the wheels have been rotated if the sensor is part of the valve stem?? it has to know somehow since i have rotated them and it still reads accurate.

11-30-2008, 01:27 PM	#2
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,931	last time i asked at the tire dealer they told me it was pressure only on most vehicles, they have to rebuild and reset them when changing tires. I'm glad i don't have them __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

11-30-2008, 05:47 PM	#6
FaselZ71 Senior Member Join Date: Oct 2008 Location: Northern Michigan Posts: 1,177	Maybe it's something simple like magnetic signatures and magnetic recepters in the hubs... or something crazy like that... __________________ IT'S PEANUT BUTTER JELLY TIME!!! http://www.youtube.com/watch?v=s8MDNFaGfT4

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11-30-2008, 02:26 PM	#3
bradrhale Senior Moderator Join Date: Apr 2006 Location: Texas Posts: 9,547	thats fine about reseting them and all but how does it know when i put move a rear tire up front?? somehow it knows since it reads correct when a tire is a little low. and i mean that literally as the beeper comes on when a tire has 26 psi in it. very sensitive.

11-30-2008, 02:44 PM	#4
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 4,645	I don't know. But my buddy next door was working on a Mercedes well the drivers window switch went out so he removed the one from the passenger door and placed it on the drivers door well the passenger window would open up even if it was connected to the drivers window wiring harness.

11-30-2008, 02:50 PM	#5
mudseeker Senior Moderator Join Date: Feb 2006 Location: michigan Posts: 7,155	maybe it's like a wireless wheel speed sensor. the valve stem could just be one half of the sensor. there may be another part of the sensor mounted on the hub. i'll ask my instructor tomorrow for you.

11-30-2008, 06:38 PM	#7
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 4,645	Each tire & wheel well has a sensor so when changed it re-sets them. It's kinda like the FLUX CAPACITOR that's on the back to the future car. For real.

11-30-2008, 07:46 PM	#8
87c10slammer Banned Join Date: Mar 2008 Location: levittown pa Posts: 2,197	i think it reads it from the direction its coming from.. like there is a sender inside the rim and a reciever inside that wheelwell... they all should be on the same frequancy so you could mount them upsidedown and backwards and it would still tell you the right from the left

11-30-2008, 08:06 PM	#9
mudseeker Senior Moderator Join Date: Feb 2006 Location: michigan Posts: 7,155	apparently there are 2 types of monitoring systems. from WIKI: In order to transfer data from a rotating wheel, Direct Sensor TPMS may use a Radio Frequency (RF) communication channel or an electromagnetic coupling means to overcome the tire/chassis rotational boundary. Indirect TPMS are realized in software in combination with wheel speed sensors for anti-lock braking systems, and electronic stability control systems. A disadvantage of indirect TPMS is that the driver must calibrate the system by pushing a reset button on the dashboard or through the on-board computer and if this is performed when any tire is in an underinflated condition then the system will not report correctly.

11-30-2008, 08:11 PM	#10
87c10slammer Banned Join Date: Mar 2008 Location: levittown pa Posts: 2,197	i like the first better... basically it has a set inflation pressure so you cant have 4 different tires of different pressures and think that there all normal