When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I searched for and did not find a thread that disclosed how often our TPMS updates our tire pressure for each tire on the dash display. I have had a tire pro tell me that our TPMS sensors are more accurate than most of the hand held units that we can purchase.
Other than a slime unit that is fluid filled I used at a track event I can not seem to get my home units synced up with what my C7 is telling me while I am trying to reset pressures after temperature changes or at the track.
Can anyone tell me how you have addressed keeping your pressures where you want them without going back and forth a dozen attempts?
I'm only one data point, but my TPMS sensors display the exact same readings as my high-quality tire-pressure gauge every time I've compared them.
Last night I put a new set of tires on the car, adjusted the pressures to 30 psi w/ my tire gauge, and this morning all 4 were reading 30 psi on the DIC display.
You guys must be at/near sea level. Here, at 6,000 feet the TPMS is off by 3-4 pounds. My monthly Onstar report is ALWAYS complaining that the tires are underinflated, when they're not.
In answer (maybe) to your question as to sample rate, the C6 TPM sensors transmit tire pressure readings once every 60 seconds while the vehicle is being driven and once every 60 minutes when the vehicle is stationary for more than 15 minutes. I could not find anywhere that shows the C7 rate, but I would imagine that it would not have changed much.
It certainly does not sample often enough to use it when filling/deleting air.
You guys must be at/near sea level. Here, at 6,000 feet the TPMS is off by 3-4 pounds. My monthly Onstar report is ALWAYS complaining that the tires are underinflated, when they're not.
I'm near good old mile-high Denver and my '16 Z06 always reads about 3 pounds low compared to my external gauge. My '14 Audi RS7, on the other hand, 'agreed' with my gauge.
My TPMS has pretty much always matched my tire gauge on my air compressor.
I hit a square bar of metal at 90+ mph and instantly got a TPMS error that said the tire had zero pressure so it definitely polls fast when an event happens.
The original message that showed up in the center was large and this was the picture I took while limping to the tire store.
Last edited by Internetguru; Nov 17, 2016 at 09:14 PM.
Well it dipped to the hi 50s last night in south Florida for 10 minutes so the tires red 28lbs. So pumped them all up to 30lbs. Used my $12. Digital gauge and the dash all read 30lbs. Warmed up to 80 by noon all read 32 lbs. All is good for the long cold winter.
The TPMS systems are generally listed for +/- 1psi, though the sensors used within them are better. Expect +/- 0.5psi to +/- 0.1psi for the actual sensor... what gets reported is the +/- 1.
The transmission rate is variable (based upon current mode, manufacturer, etc.), but expect a sample about once every 10 seconds.
They are as accurate as all of the hand held gauges on the market. None of them are calibrated so actual accuracy to a known standard is not really known. Hand held gauges from the pencil sticks to the most expensive fluid filled guages are pretty much the same accuracy. The big difference with them is resolution. A pencil stick may be accurate to +/- 1 lb but you can't read (resolution) it that close. An expensive gauge may have the exact same accuracy but it is much easier to to read and lets you get closer to the actual pressure you are trying to set.
The TPMS systems are generally listed for +/- 1psi, though the sensors used within them are better. Expect +/- 0.5psi to +/- 0.1psi for the actual sensor... what gets reported is the +/- 1.
The transmission rate is variable (based upon current mode, manufacturer, etc.), but expect a sample about once every 10 seconds.
This sounds about exactly right. I've been watching the TPMS display frequently now that we're having cold mornings. I see the inflation readings going up and down about every 10 seconds as they are heating up.
C7 TPMS sampling rate and accuracy
