TPS sensors

[opie6051]

My TPS sensors are reading high on my 2010 C14.......2 tire pressure gauges are reading 42 and the TPS's are reading 47......anyone have input on TPS failure patterns?......do they read high?...low?....or just die all of a sudden?....thanks for any help!........Chris

 

[Cap'n Bob]

  I do not remember folks mentioning sensors changing or anything.  IS this both at cold tire pressure, warm or at different times? Normally when they go, they either just stop working, or in my case, the low battery warning would come on at higher and higher ambient temperatures (as the battery got weaker). So no, I do not remember anyone ever saying that the temperature sensor actual readings (in relation to cold tire pressure) had changed it's readings. But that's not saying it couldn't be the first we hear of it.

  For what it's worth to folks new to the bike or researching the bike. IMO the tire pressure sensors (TPS) are nothing more than a tool to let you somewhat monitor tire pressures. Mine were pretty close to accurate and only read slightly high (all the time). As always I recommend using a good quality gauge to set your cold tire pressures. Then immediately riding the bike a check the offset difference of your TPS sensors. That way you will have an idea where your sensors actually are reading in relation to reality.
    For example: With tire gauge cold @ 42PSI, the dash might read 43 or 44. They of course should go up as tires warm up, thus higher readings yet. So once warm the TPS might read 47PSI.
  Myself I only used it as a tool to monitor tire pressures. Obviously they will go up slightly as the tire warms up, and cools when it has been parked for a bit. But the real use is to be able to see the pressure dropping when your riding. I use to always monitor pressures and could see if a problem was developing. But a fast problem will set of the Warning for tire pressures. And that's what it's all about in my opinion.

 

[Brass]

I also have several pressure gauges showing 42 psi with 47 showing for front and rear on the bike

 

[Fred H.]

Is this a digital or an analog gauge you are using to measure with and what is the ambient temp when you are taking the measurement?

 

[OMoaC]

Altitude diff betweeen PSIG and PSIA?

 

[Brass]

Is this a digital or an analog gauge you are using to measure with and what is the ambient temp when you are taking the measurement?

Well i used a high end liquid filled racing guage which is calibrated annually and two cheaper digital gauges and a pencil guage all showing 42 psi copared to the 47 psi on the bike readout

 

[Fred H.]

There are a couple things that could cause this. First off, you have to understand that the TPS system in the Concours is temperature compensated, and the "set point" is calibrated at 68 degrees. So if you check your tires with a manual gauge when the tires are at a higher temperature than 68 degrees, your gauge will read higher, and if you check them at a lower temperature than 68 degrees your gauge will read lower.

Furthermore, the rate of expansion of air versus temperature is not only depended on volume, but also the moisture content of the air. So if you got a lot of water in your tires from your air compressor, this will throw off the temperature compensation values from your TPMS. The drier the air you can use to fill your tires with, the more accurate your TPMS system will be. I use a "desiccant snake" on my air hose when I fill my tires to keep moisture content low in them, and this works well.

The other thing you have to keep in mind is gauge error. Analog pressure gauges are subject to mechanical induced errors and as such are not generally as precise as digital gauges are. I'd suggest buying a digital tire gauge and using it instead of a mechanical one. All of the digital Accutire gauges are very good, even the cheaper models. You can get them on Amazon.com for under $10. I have tested almost a dozen of them, and every one of them gives me identical readings, so they give very repeatable results.

 

[Brass]

There are a couple things that could cause this. First off, you have to understand that the TPS system in the Concours is temperature compensated, and the "set point" is calibrated at 68 degrees. So if you check your tires with a manual gauge when the tires are at a higher temperature than 68 degrees, your gauge will read higher, and if you check them at a lower temperature than 68 degrees your gauge will read lower.

Furthermore, the rate of expansion of air versus temperature is not only depended on volume, but also the moisture content of the air. So if you got a lot of water in your tires from your air compressor, this will throw off the temperature compensation values from your TPMS. The drier the air you can use to fill your tires with, the more accurate your TPMS system will be. I use a "desiccant snake" on my air hose when I fill my tires to keep moisture content low in them, and this works well.

The other thing you have to keep in mind is gauge error. Analog pressure gauges are subject to mechanical induced errors and as such are not generally as precise as digital gauges are. I'd suggest buying a digital tire gauge and using it instead of a mechanical one. All of the digital Accutire gauges are very good, even the cheaper models. You can get them on Amazon.com for under $10. I have tested almost a dozen of them, and every one of them gives me identical readings, so they give very repeatable results.

So far the ambient temperature has not seemed to make a difference with the same errors weather it 19F or 60F

I agree with you using dry air but your advice that digital guages are better than analog is just not true.  I have a little bit of knowledge on this subjectbeing i deal with guages day in and day out.

 

[Fred H.]

Go take a look at what kind of tire gauges the guys in NASCAR use. It isn't a mechanical one.

 

[Brass]

Go take a look at what kind of tire gauges the guys in NASCAR use. It isn't a mechanical one.

I'll give you that but it's also not a $10 one.  Digital gauges that are accurate are not cheap

 

[Fred H.]

Go take a look at what kind of tire gauges the guys in NASCAR use. It isn't a mechanical one.

I'll give you that but it's also not a $10 one.  Digital gauges that are accurate are not cheap

Compare two tire pressure gauges in the same price range, one mechanical and one digital. I can buy a $6 Accutire gauge from Amazon that is very accurate. Show me a $6 mechanical gauge that can even come close.

 

[juve]

those digital nascar gauges are great if you're only turning left
)

 

[rmc_ss_ldo]

Chris,

  Can't speculate as to the readings changing as the sensors age, but I can tell you that this time of year (also in the Northeast) they will indicate higher than you would expect.  I say that when they work- getting consistant low battery warnings due to the temp and my bike is a 2009...

  Using two known-good tire gages (one mechanical, one digital) if the temps out are low and I set the pressure on a cold tire at 42, the TPMS sensors will indicate around 47.  When I say cool temps, I am talking low 40's.  In the summer months last year (temps in the 80's) the TPMS sensors tracked more closely with the gages...

  I realize the TPMS compensate for temps- just offering my observations.  I can also say that when it is cold out if I lower the pressures in the tires to ~42 indicated on the TPMS, the bike handles like a pig and does in fact feel like it is on a low tires.  My solution is to check the pressures with a gage on any given day then note the delta on what the TPMS shows while the tires are still cold. 

  I'd also suggest picking up an Accutire digital gage- the MS-4652B is a compact key-chain style gage that is consistently dead-on.  It is perfect to throw in the console storage pooka, it is small enough to easily fit on the tire stem in the wheel and the best part is it has an access to change the batteries.  Best $8 I've spent in a long time...

Allen

 

[opie6051]

Thank you all for a great discussion on a topic I never would have guessed could have so many details!.....always impressed with the cumulative knowledge and willingness to share of COG......Chris

 

[smooth_operator]

In my highly entertaining and easy reading owners manual it states that the sensor pressure on the screen can be different from an actual guage reading and that you shouldn't rely on the screen reading but take acutual guage readings.

 

[rmc_ss_ldo]

In my highly entertaining and easy reading owners manual it states that the sensor pressure on the screen can be different from an actual guage reading and that you shouldn't rely on the screen reading but take acutual guage readings.

:iagree:

Since moving north into colder climates, I have started relying much more on a good gage for my baseline then checking the dash for info only...

I still like the idea of the TPMS for long highway trips if a tire is going down (from a safety perspective) but personally, I can tell if my tires are off by more than 2 PSI just by how the bike feels...

/r

Allen

 

[Bruiser]

Personally, I think the TPS sensors are a PIA.  As the weather is a bit cooler, they tell me a bit more often of low battery.  That disallows me from concentrating on the ride, what with the constant flashing of the deflated tire icon.