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Discussion Starter #1
Maybe it's just my car, but when I get a TPMS warning, even after I correct the inflation pressures to equalize all four tires, it typically takes 2-3 days and over 100 miles minimum of driving for the warning lights to go out. This seems an absurdly long time, and I was wondering if it is typical to other owners experiences. I did have early TPMS problems when the car was nearly new that required a replacement of the BCM (body control module) which reads the radio signals that the TPMS sensors send out, and was wondering if it is going bad again. I even occasionally get the warning on two tires being low even though the indicated pressures are the same on all 4 tires. Weird! Anyone else experiencing this?
 

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It should take more then putting on a 1-2 miles for them to reset. But I'm talking about a ICE vehicle, not a EV.
 

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IF THE LIGHT STARTS FLASHING INDICATING A LOW TIRE PRESSURE, ADJUST THE AIR PRESSURE IN THE LOW TIRE TO THE AIR PRESSURE SHOWN ON THE VEHICLE PLACARD OR TIRE INFLATION PRESSURE LABEL LOCATED ON THE DRIVER'S DOOR.
Note:AFTER INFLATION, THE VEHICLE MAY NEED TO BE DRIVEN FOR UP TO 20 MINUTES BEFORE THE FLASHING LIGHT WILL GO OFF.
 

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I got new tires a couple weeks ago; 2 of the 4 TPMS reset within a couple minutes, 1 took 5-20 minutes and 3 or 4 start ups, the forth took 2 days, over 100 miles and 3+ hours of driving time...it's that Italian efficiency ;)
 

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Discussion Starter #8
The strange thing is that I tried adding air to all 4 tires to a very accurate gage-verified, higher setting, hoping to clear the warning, and the display does immediately show the new pressures, all at the same pressure, but the front two tires are shown highlighted as being "low" and the warning light remains on, even after 2 days and 90 miles of driving. Time for a dealer visit I guess.....
 

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I recently had a low tire warning light and it went away in less than a few hundred feet of driving. The 2015 lcd display also updates the on screen tire pressure numbers a few seconds after adding air if you do not have a guage handy.
 

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The strange thing is that I tried adding air to all 4 tires to a very accurate gage-verified, higher setting, hoping to clear the warning, and the display does immediately show the new pressures, all at the same pressure, but the front two tires are shown highlighted as being "low" and the warning light remains on, even after 2 days and 90 miles of driving. Time for a dealer visit I guess.....
You might have a bad sensor. My right front sensor battery went dead. Had to be replaced. It did indicate at start up which sensor was bad. Only first thing in the morning. The tire monitor lamp stayed on, after that.They can run a code, to see if you have a bad one. I bet that's you problem.
 

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Discussion Starter #12
Update...as you might recall, both my front tires were throwing an low pressure alarm, even though the indicated pressures were reading identical on all 4 tires, and verified with a manual gauge. I even aired all 4 up to a higher pressure, the indicated pressure on all 4 tires indeed did go up to the new pressure, but the warning stayed on. finally, after about 1 week and 200+ miles, the warning lights went out. I don't believe it was sensor batteries going low, because there was still an accurate pressure readout on the cluster. I recently did have some unrelated software upgrades done to the car, maybe it's a unexpected bug related to that, or a funk BCM module. At least the **** light in now out (for now at least).
 

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Update...as you might recall, both my front tires were throwing an low pressure alarm, even though the indicated pressures were reading identical on all 4 tires, and verified with a manual gauge. I even aired all 4 up to a higher pressure, the indicated pressure on all 4 tires indeed did go up to the new pressure, but the warning stayed on. finally, after about 1 week and 200+ miles, the warning lights went out. I don't believe it was sensor batteries going low, because there was still an accurate pressure readout on the cluster. I recently did have some unrelated software upgrades done to the car, maybe it's a unexpected bug related to that, or a funk BCM module. At least the **** light in now out (for now at least).
Glad things finally panned out, def took a bit though!
 

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That's strange. When the weather got cooler and I needed to add air to mine, I went to a gas station and left he car running. All of my tires were low, in the high 20's and low 30's. After I filled up and got in the car, the pressure was corrected on the gauges before I even drove the car off. No rotational speed required. I know there are a few different types of gauges and how they read. Nissan uses one similar because the new Altima honks the horn while you are filling up the tires to tell you when to stop adding air.
 

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...the new Altima honks the horn while you are filling up the tires to tell you when to stop adding air.
A little barbaric, but I love the concept! I don't understand why manufacturers are just now coming around to give us cool tech in cars. And why there are these features that only some have and others don't. Roll them all into one and we might have a really fun car!


-motofabio
 

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Discussion Starter #16
There are two styles of TPMS in use today.

The best design in my opinion, and this is what Fiat uses, is an actual air sensor located inside each tire that transmits the tire pressure information via radio signal to a centralized sensor, which the car computer evaluates for two things, relative pressure comparison between all 4 tires, which will trigger an alert. There is also a minimum pressure threshold I looks for, so if all 4 tires are the same pressure, but too low, it will trigger an alert.

The other design relies on the readings from the ABS sensor located at each wheel. Those sensors gather each wheels RMP, and if there is a tire with low pressure, it will rotate at a slightly lower RPM than the others, and the car will trigger an alert.
 

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First cold rainy day in LA, I got the air pressure warning. Front left @ 27.5 psi, I think. Airing up in the morning and will report back on how long it takes to clear.


-motofabio
 

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Yesterday I was getting a warning light from the LF at 34.8lbs :-/ seriously, two tenths under and the light wouldn't go off...
 

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Oh, is 35 psi the recommended pressure? I run my Suzuki Samurai, which is about 2000 lbs, at 25 psi. I thought the Fiat at 2500 lbs would want less, but more than 32 psi seems excessive.


-motofabio
 
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