Author Topic: TPMS inaccurate in the cold?  (Read 7023 times)

Offline Mister Tee

  • Full Member
  • ***
  • Posts: 493
  • Country: 00
TPMS inaccurate in the cold?
« on: December 18, 2011, 01:13:22 PM »
Ok so get up at zero dark thirty and it's hella cold out there, and in the garage.  I just returned from six weeks in Southeast Asia so my bike has sat all that time.  Everything looks fine, tires appear hard, and I'm out for a short ride.  Fire up the bike (whew, it still cranks) and take off.  TPMS shows 38 F 41 R.  A tad lower than I want, but fine for now.

The bike just doesn't feel right.  Steering is heavy, it just feels off.  Granted, I've been tooling around on a 125 cc Honda Elite motorbike for the last six weeks, so I chalk it up to that.  Later in the day, when it's warmer and I feel like screwing around in the garage, I fire up the compressor so I can fill all tires that need filling.  My slime gauge reads 32 F 38 R (WTF?)  so I fill it back up to 42/42, which is where I like it.  Get back on the bike.  Rides like it should, feels good again.  TPMS is reading 47/47.

TPMS so far has been fairly accurate, to within a couple pounds of a gauge, but for whatever reason it's really off now.  The only thing that is different between now and six weeks ago is that it was a whole lot warmer outside.  Anyone else notice that?

Offline McJunkie

  • Full Member
  • ***
  • Posts: 143
  • Country: us
Re: TPMS inaccurate in the cold?
« Reply #1 on: December 18, 2011, 02:51:13 PM »
Same thing happened to me. Once it got cold out the TPMS read 3-5 lbs higher than the Accu-Gauge I use. Took the gauge inside for a day to warm it up and now it's back to being only 1 lb off. I attribute it to the gauge being affected by the temp rather than the TPMS. Maybe it's a little of both.

Offline PH14

  • Sr. Member
  • ****
  • Posts: 1254
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #2 on: December 18, 2011, 05:09:25 PM »
I juste went out, it's about 32F out and my TPS is spot on. I have always had no issue with it, it reads the same as the gauge I use no matter the temp.

Offline jjsC6

  • Full Member
  • ***
  • Posts: 592
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #3 on: December 18, 2011, 05:19:57 PM »
I suggest a forum search.  The system compensates for temperature.  Don't ask me to explain it - it's magic.  I'll try to find it.

Here... http://www.zggtr.org/index.php?topic=1248.msg12456#msg12456

BTW, the chart does not jive with what you are seeing, but it's good information anyway.
Jim
2010 Concours - Sold Feb 2013
Current bikes....
2011 Ninja 1000, 2013 BMW 1600 GT, 2012 Ducati Panigale

Offline Mister Tee

  • Full Member
  • ***
  • Posts: 493
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #4 on: December 18, 2011, 05:32:29 PM »
I suggest a forum search.  The system compensates for temperature.  Don't ask me to explain it - it's magic.  I'll try to find it.

Here... http://www.zggtr.org/index.php?topic=1248.msg12456#msg12456

BTW, the chart does not jive with what you are seeing, but it's good information anyway.

Yes, I know about forum searches!  I am familiar with the temperature compensation feature of TPMS.  I am observing what I believe to be an, I need a word.  Anomoly.  I have observed an anomoly.  That is the justification I am using to start a new topic.

Offline jjsC6

  • Full Member
  • ***
  • Posts: 592
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #5 on: December 18, 2011, 07:08:50 PM »
Yes, I know about forum searches!  I am familiar with the temperature compensation feature of TPMS.  I am observing what I believe to be an, I need a word.  Anomoly.  I have observed an anomoly.  That is the justification I am using to start a new topic.

Wow, didn't mean to offend you with my reply  ;)
Jim
2010 Concours - Sold Feb 2013
Current bikes....
2011 Ninja 1000, 2013 BMW 1600 GT, 2012 Ducati Panigale

Offline Mister Tee

  • Full Member
  • ***
  • Posts: 493
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #6 on: December 19, 2011, 11:12:05 AM »
Sorry - I mod on another site and call people out all day long for not doing forum searches.  I was half cranky and half joking!

Offline Rhino

  • Arena
  • Hero Member
  • *****
  • Posts: 3963
  • Country: us
Re: TPMS inaccurate in the cold?
« Reply #7 on: December 19, 2011, 11:38:26 AM »
The accuracy of my TPMS has changed over time. It changed a lot with my last rear tire change. it now reads 3-4 psi low. Whenever I check my tires I always match it to the TPMS so I have an idea of what the actual pressure is.

Offline Tim

  • Full Member
  • ***
  • Posts: 215
  • Country: us
Re: TPMS inaccurate in the cold?
« Reply #8 on: December 19, 2011, 01:53:52 PM »
I bet it was some what warmer 6 weeks ago. 6 weeks ago I would still be riding.   ;)

As the temps go down so does the air pressure in your tires. (cars too) I like to have the proper T/P when I take off but normally once the tires warm up a bit, the sensors get closer to being what I want. I've seen the T/Ps go up and down just by going from warmer outside air to colder outside air or visa versa while out on a ride. 

Could be the battery in your fob is getting weak.
I don't always ride a street bike. But when I do, it's a Concours. Ride safely my friend.

Offline jjsC6

  • Full Member
  • ***
  • Posts: 592
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #9 on: December 19, 2011, 02:37:11 PM »
Sorry - I mod on another site and call people out all day long for not doing forum searches.  I was half cranky and half joking!

I wasn't cranky, but I was only half joking as well (hence the  ;)). 
Jim
2010 Concours - Sold Feb 2013
Current bikes....
2011 Ninja 1000, 2013 BMW 1600 GT, 2012 Ducati Panigale

Offline VirginiaJim

  • Administrator
  • Elite Member
  • *****
  • Posts: 11333
  • Country: england
  • I've forgotten more than I'll ever know...
    • Kawasaki 1400GTR
Re: TPMS inaccurate in the cold?
« Reply #10 on: December 19, 2011, 03:12:31 PM »
Mine seem more 'off' with the cold as well...  I don't worry about it.  I check with the gage before starting out.  I only use the TPMS for wild swings down.  I wouldn't trust it for anything else.
"LOCTITE®"  The original thread locker...  #11  2020 Indian Roadmaster, ABS, Cruise control, heated grips and seats/w/AC 46 Monitoring with cutting edge technology U.N.I.T is Back! Member in good standing with the Knights of MEH.

Offline rcannon409

  • Full Member
  • ***
  • Posts: 619
Re: TPMS inaccurate in the cold?
« Reply #11 on: December 19, 2011, 05:12:33 PM »
Mine read low in warm (85 degree plus) temps.  In the 30-50 range its accurate.  I have a decent Factory KTM gauge and the TPS is always 3-4 psi lower than it is. I did notice at 12 degrees my front tps gave me a low battery warning.


Offline PH14

  • Sr. Member
  • ****
  • Posts: 1254
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #12 on: December 19, 2011, 06:19:39 PM »
I only use the TPMS for wild swings down. 

+1

Offline Curt

  • Arena
  • Newbie
  • *
  • Posts: 19
Re: TPMS inaccurate in the cold?
« Reply #13 on: December 20, 2011, 09:05:38 AM »
the TPMS on my '08 has been inaccurate from day one. however, it is consistantly inaccurate. TPMS actually reads 4 pounds higher than any of my gauges. It is not a feature that I will spend any money to fix when the warranty expires.

Offline B.D.F.

  • Hero Member
  • *****
  • Posts: 4955
  • Country: 00
  • It's only really cold if you fall down in it.
    • C-14 farkles you almost cannot ride without.
Re: TPMS inaccurate in the cold?
« Reply #14 on: December 20, 2011, 12:47:44 PM »
The tire pressure sensors are temperature compensated and will not read the same as a normal (not temperature compensated) tire pressure gauge. If the tires were pressurized to 42 PSI at 70 degrees F for example, when the temp. drops to 40 F the pressure will drop to something like 39 PSI, which an external gauge will show. The TPS sensors will continue to show the pressure is something like 42 PSI at the lower temp. So if you inflate the tires to the higher pressure at a lower temperature, the TPS will show a higher reading because of the low temperature.

The reason the sensors are temperature compensating is so that the pressures do not read very high when riding the bike- it would tend to put the owner off and would probably lead to him / her stopping and reducing the tire's pressure while hot (which is not the right thing to do). Compensating for temperature is a judgment call that the chip manufacturer made when designing the controller.

Brian



Ok so get up at zero dark thirty and it's hella cold out there, and in the garage.  I just returned from six weeks in Southeast Asia so my bike has sat all that time.  Everything looks fine, tires appear hard, and I'm out for a short ride.  Fire up the bike (whew, it still cranks) and take off.  TPMS shows 38 F 41 R.  A tad lower than I want, but fine for now.

The bike just doesn't feel right.  Steering is heavy, it just feels off.  Granted, I've been tooling around on a 125 cc Honda Elite motorbike for the last six weeks, so I chalk it up to that.  Later in the day, when it's warmer and I feel like screwing around in the garage, I fire up the compressor so I can fill all tires that need filling.  My slime gauge reads 32 F 38 R (WTF?)  so I fill it back up to 42/42, which is where I like it.  Get back on the bike.  Rides like it should, feels good again.  TPMS is reading 47/47.

TPMS so far has been fairly accurate, to within a couple pounds of a gauge, but for whatever reason it's really off now.  The only thing that is different between now and six weeks ago is that it was a whole lot warmer outside.  Anyone else notice that?
Homo Sapiens Sapiens and just a tad of Neanderthal but it usually does not show....  My Private mail is blocked; it is not you, it is me, just like that dating partner said all those years ago. Please send an e-mail if you want to contact me privately.

KiPass keeping you up at night? Fuel gauge warning burning your retinas? Get unlimited peace and harmony here: www.incontrolne.com

Offline Mister Tee

  • Full Member
  • ***
  • Posts: 493
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #15 on: December 20, 2011, 03:00:11 PM »
The tire pressure sensors are temperature compensated and will not read the same as a normal (not temperature compensated) tire pressure gauge. If the tires were pressurized to 42 PSI at 70 degrees F for example, when the temp. drops to 40 F the pressure will drop to something like 39 PSI, which an external gauge will show. The TPS sensors will continue to show the pressure is something like 42 PSI at the lower temp. So if you inflate the tires to the higher pressure at a lower temperature, the TPS will show a higher reading because of the low temperature.

The reason the sensors are temperature compensating is so that the pressures do not read very high when riding the bike- it would tend to put the owner off and would probably lead to him / her stopping and reducing the tire's pressure while hot (which is not the right thing to do). Compensating for temperature is a judgment call that the chip manufacturer made when designing the controller.

Brian

Okay, I didn't quite understand temperature compensation.  I previously thought it was just for device error compensation but what you are saying is that it normalizes the pressure to a standard temperature.  I suppose I get the logic of it but I'm not sure I like that.  If it gets cold, the pressure drops, and I want to put more air in to it to restore the lost pressure.  And vice versa.

Offline B.D.F.

  • Hero Member
  • *****
  • Posts: 4955
  • Country: 00
  • It's only really cold if you fall down in it.
    • C-14 farkles you almost cannot ride without.
Re: TPMS inaccurate in the cold?
« Reply #16 on: December 20, 2011, 03:07:35 PM »
Yep, that is why I mentioned it being a judgment call- there is no 'right' way to do it but many choices.

My opinion is that if the pressure indicated were not temperature corrected, a lot of people would be going nuts wondering and worrying about the fluctuating pressure as they rode. Some would try to adjust the pressure so it was the 'right' reading as the tires heated and cooled resulting in severely under inflated tires when running on the highway on a warm day. And most of the above would result in a lot of cranky calls to dealers and the mfg. regarding the fluctuating readings. Like Jack Nicholson said....' You can't handle the truth!'  or something similar.  :-)

Brian

Okay, I didn't quite understand temperature compensation.  I previously thought it was just for device error compensation but what you are saying is that it normalizes the pressure to a standard temperature.  I suppose I get the logic of it but I'm not sure I like that.  If it gets cold, the pressure drops, and I want to put more air in to it to restore the lost pressure.  And vice versa.
Homo Sapiens Sapiens and just a tad of Neanderthal but it usually does not show....  My Private mail is blocked; it is not you, it is me, just like that dating partner said all those years ago. Please send an e-mail if you want to contact me privately.

KiPass keeping you up at night? Fuel gauge warning burning your retinas? Get unlimited peace and harmony here: www.incontrolne.com

Offline lt1

  • Full Member
  • ***
  • Posts: 489
  • Country: us
  • 2008 C14
Re: TPMS inaccurate in the cold?
« Reply #17 on: December 20, 2011, 08:17:10 PM »
<snip>
Like Jack Nicholson said....' You can't handle the truth!'  or something similar.  :-)
Brian

Perfect summation of the vast majority of the TPMS threads.  :thumbs:
Eyes, Brain, Hands.  Repeat.

Offline marku8a

  • Full Member
  • ***
  • Posts: 199
  • Country: 00
Re: TPMS inaccurate in the cold?
« Reply #18 on: December 20, 2011, 08:49:03 PM »
Yep, that is why I mentioned it being a judgment call- there is no 'right' way to do it but many choices.

My opinion is that if the pressure indicated were not temperature corrected, a lot of people would be going nuts wondering and worrying about the fluctuating pressure as they rode. Some would try to adjust the pressure so it was the 'right' reading as the tires heated and cooled resulting in severely under inflated tires when running on the highway on a warm day. And most of the above would result in a lot of cranky calls to dealers and the mfg. regarding the fluctuating readings. Like Jack Nicholson said....' You can't handle the truth!'  or something similar.  :-)

Brian


Actually it was making me nuts wondering why pressure reading didn't change with changing conditions. I didn't know about the compensation feature. I always adjust my pressures just like the load rating molded onto the sidewall of the tire recommends... "cold".

Mark
2009 C14 Red
Fly_ectomy, K&N Filter, Oxford Heated Grips, PC V, Full Area P Exhaust
How far can a person run into a forest?

Offline stewart

  • Full Member
  • ***
  • Posts: 296
Re: TPMS inaccurate in the cold?
« Reply #19 on: December 21, 2011, 06:04:49 AM »
Was it this forum or another that discussed how the Temo gauge in a car always shows the same Temp until something is really wrong. The explanation I heard was if the guage showed the true temp, and people saw the fluctuations ie sitting still at the lights, then they would think there is a problem. So they design it to be steady eddie (technical term) to keep everyone calm.

So relax, be happy.
Stewart
2010 Concours14
COG 9380