Anyone seeing their tpms being off?

[Catless]

To add to the confusion, you cannot count on your TPMS to show the wheels in correct position. Ignoring that I find ours to be accurate enough +/- 1 PSI or so.

 

[Decay]

Whatever did we do before TPMS!!??
Is there a system for your trailer that links to your phone that shows hub temp as well?

 

[DGatzby]

Whatever did we do before TPMS!!??
Is there a system for your trailer that links to your phone that shows hub temp as well?

Good one. I just don't know how we ever could have successfully done this before. We can now put remote cameras in the back window of the vehicle being towed, we can turn on our reverse camera in the tow vehicle, we have on board computers and items to equalize and level the load, help with sway, we got more navigation computer power than they did going to the flipping moon, just to get to another city!

Like I said previously the TPMS works pretty damn good and I have confirmed it over and over again. I like it.

 

[DRAGRCR]

Anyone seeing their tpms being off? I have two tire gauges which both show 2psi lower than what the on board display will read. Gauges will read 30 and on board will read 32 cold.

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I am very picky, so I am going to throw in my two cents here. First of all, if you are just taking a snap shot of the pressures you are in for a shock. You MUST have the display up and keep an eye on it to understand what is going on. In my experience I have found the TPMS to be very accurate and very reliable as far as the location of which tire is which, being correct. There have been times where I go to Irwindale every week and lower the tires and then raise them back up at the end of the night and they are ALWAYS in the correct placement.

If you look at the pressure when you first turn the car on in the morning you are seeing STALE readings from the last time you drove the car. If they are KNOWN and LEARNED sensors they will update within a mile or two. If they are new to the car it might take 15 or 20 minutes/miles. The car can learn and keep track of two sets of sensors. But if you rotate and do not drive much they can be in the wrong location. If you DRIVE for a little while they will straighten out. If you are driving and they are all set to the same pressure physically then you can get really goofed up because not only is the system reshuffling locations but it may be reporting a stale pressure reading on one and then on another it is giving you an updated correct reading. Most of you are looking at the system once and assuming. I have it up almost the whole time I drive and I can assure you the system is accurate.

So, as you drive the pressures will go up. If you are heading in one direction and the sun is on one side of the car that side will read higher. Depending on if the new drive ambient temp is way higher or way lower and on screen info is stale or current the readings can be very confusing. Best thing to do is look at the system after driving for 15-20 minutes or not at all.

Also the TPMS is very accurate to high pressures. My front MT Sportsman SR is set to 80 PSI, just that one tire takes this high pressure and it is very accurate. 80 COLD and go up to 85 driving around. Totally normal.

I have found the system to be very accurate at low pressures as well 10-15 psi. I watch this screen closely at the track. I also use it to set my pressures when airing up at the end of the night. It's a good idea to have the engine running when using the 12 V air compressor that way you have 14 V alternator voltage. So I watch the dash TPMS reading as I pump up the tires. Sometimes it is a little sluggish but most of the time it's pretty good with a slight lag on actual pressure. 29 PSI is still red and as soon as it sees 30 or higher it pops up Green and I stop. I even air up the tires if I am trailering the car. So I have literally done this HUNDREDS of times. I have NEVER once seen a right tire mixed up with a Left or a Front mixed up with a rear on known learned Sensors.

The only time I have seen readings out of place was in fact resently with my new RedEye. Changed out all 4 wheels/tires with brand new Forgestars and MT Tires with new TPMS. I turned the car on and drove 5 minutes away to shoot photos. So at the point when I turned the car off they had not been learned yet (stale readings from the old tires). I started the car once to turn it around and took more pics. Then I started the car and went for a drive to put on some break in miles. One front and rear were reversed so the pressures were crosseyed. As soon as I drove 10 minutes they went to the proper position/location on the display and it is real obvious because of the 32 Cold VS 80 Cold from front to back. So, just drive the car and give it time.

Also if the car has missing TPMS it will wait quite a while before it raises the red flag. I swapped on 4 wheels/tires that had NO TPMS. When I drove it , the display showed stale readings for at least 15 or possibly 20 minutes of driving before it gave me a warning light and red dashes where all the readings should be. Keep in mind this was not the same as having a low tire. An absent TPMS signal is not the same as a REPORTED low pressure. A reported low pressure will immediately show a warning lamp in the dash.

Also since I am so picky, maybe some of you have not caught onto this. If you lower a big ol drag radial from 32 PSI to 15 and then come back in 10 minutes it will read 15-1/2 PSI. I am thinking it is because of the tire carcus relaxing or tightening. Now that I have a good digital to .1 PSI Gauge this is even more freaky. You literally need to keep the gauge on there for several seconds to let the pressure normalize even when making small final adjustments. So if you set your pressures and then you remember something was not just perfect on one tire and go back and adjust it, that one tire will be .5 psi low. Also the TPMS only reads whole numbers. So some are rounding up and some are rounding down. You guys are noting that they read different??? Well the pressure from right to left or front to back might only be .1 PSI different actual but the system shows one whole PSI. Just give it time because they are ALL constantly changing in PSI. I am anal as hell and on my RedEye many times the readings are perfect and sometimes they are not. I just look down 5 minutes later and they are good.

Hope this helps.