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View Full Version : No tire pressure monitoring when it's (very) hot.



cdysthe
06-28-2013, 12:32 PM
Hi,

I noticed a week or so ago when I started my 500 that tire pressure monitoring wasn't working. It told me it wasn't available and was flashing. The next morning I took it in to the dealer who told me it worked fine, but that they had reprogrammed it (whatever that means). That same day around 3 pm I was going for a drive and I got the same error message from tired pressure monitoring. But that same night when I went for a driver no error. I have been watching this for a few days and it turns out this has to do with outside temperature. Every time I've gotten the error the temperature has been 100F+. Have anyone else noticed problem with tire pressure monitoring in (very) hot weather?

Fiat500USA
06-28-2013, 12:38 PM
Hi,

I noticed a week or so ago when I started my 500 that tire pressure monitoring wasn't working. It told me it wasn't available and was flashing. The next morning I took it in to the dealer who told me it worked fine, but that they had reprogrammed it (whatever that means). That same day around 3 pm I was going for a drive and I got the same error message from tired pressure monitoring. But that same night when I went for a driver no error. I have been watching this for a few days and it turns out this has to do with outside temperature. Every time I've gotten the error the temperature has been 100F+. Have anyone else noticed problem with tire pressure monitoring in (very) hot weather?


I have aftermarket wheels from TireRack and I occasionally get that, too. It is annoying. Another Government mandated system to drive consumers mad. I don't know but maybe getting your tires filled with nitrogen may help? I've heard that it prolongs the life of the TPMS.

cdysthe
06-29-2013, 02:53 PM
I have aftermarket wheels from TireRack and I occasionally get that, too. It is annoying. Another Government mandated system to drive consumers mad. I don't know but maybe getting your tires filled with nitrogen may help? I've heard that it prolongs the life of the TPMS.

I'm under warranty with stock (Continental) tires, the car only has 400 miles on it. I just want it to work at all times. The problem is that when I take it in to the dealer it works since it's in the morning. It never happens until it gets hot during the day. I think I need to set up an appointment in the early afternoon when it's most likely not to work. I wonder why TPMS is affected by the outside temperature though?

Abarth Phreak
06-29-2013, 08:35 PM
What PSI are you running? Too low from the start could affect the TPMS when the tires get to a hotter temperature, such as simply driving or on hot days when the asphalt superheats the inner air of the tire. This would make sense as to why the tires act up during the day and not at night. I run 40 psi on mine just for reference. The TPMS on this car is the same Hz system used on many cars...so it is unlikely a "Heat" problem, however I am not ruling that out. Try inflating them a few PSI and see what happens. Also, let us know of any thing you do find out. Good luck!

Felnus
06-29-2013, 08:42 PM
If the pressure was too low, the hotter temperatures would cause the air to expand, increasing the pressure within the tire, not the opposite. I wonder if there is a loose connection on one of the sensors that picks up the signals from the units inside the wheels. It may be mounted to a thin piece of metal and as that expands at high temperatures, it loses connection and then regains connection when it cools down?

cdysthe
06-29-2013, 09:04 PM
What PSI are you running? Too low from the start could affect the TPMS when the tires get to a hotter temperature, such as simply driving or on hot days when the asphalt superheats the inner air of the tire. This would make sense as to why the tires act up during the day and not at night. I run 40 psi on mine just for reference. The TPMS on this car is the same Hz system used on many cars...so it is unlikely a "Heat" problem, however I am not ruling that out. Try inflating them a few PSI and see what happens. Also, let us know of any thing you do find out. Good luck!

Thanks! I'm running what it says on the door frame label: 33 front and 30 back. Much lower than you. Funnily enough the car had 40 psi front and back when the car was delivered but I lowered to 33/30 since that it what it says. Are you suggesting I try increasing it to 40 to see if it helps?

cdysthe
06-29-2013, 09:09 PM
If the pressure was too low, the hotter temperatures would cause the air to expand, increasing the pressure within the tire, not the opposite. I wonder if there is a loose connection on one of the sensors that picks up the signals from the units inside the wheels. It may be mounted to a thin piece of metal and as that expands at high temperatures, it loses connection and then regains connection when it cools down?

If there's a loose connection the dealership must have missed it when they had the car in. They told me they calibrated TPMS but didn't find any problems. I guess I need to run down to the dealer next time it happens making sure it's bad when I arrive. Shouldn't bee to hard since it happens several times a day. Thanks!

Abarth Phreak
06-30-2013, 12:55 AM
If the pressure was too low, the hotter temperatures would cause the air to expand, increasing the pressure within the tire, not the opposite. I wonder if there is a loose connection on one of the sensors that picks up the signals from the units inside the wheels. It may be mounted to a thin piece of metal and as that expands at high temperatures, it loses connection and then regains connection when it cools down?

You are correct...I do not know how I got that backwards, but thanks! I still run my tires at 40 PSI cold for fuel efficiency and HOT check them occasionally at about 41-42 PSI. The connection theory is potentially valid too. I would still take it back to the dealer when the light is actually on if possible. The TPMS sensors are battery powered, and the batteries are sealed. There is a chance that one of them is also not communicating very well in that regard also.

Evelyn Salt
06-30-2013, 11:49 AM
Thanks! I'm running what it says on the door frame label: 33 front and 30 back. Much lower than you. Funnily enough the car had 40 psi front and back when the car was delivered but I lowered to 33/30 since that it what it says. Are you suggesting I try increasing it to 40 to see if it helps?
You need to put at least 35 front and rear for better daily performance and mileage.
My tpms doesn't work when I first start , but is all right as I drive a few 10th's of a Mile.

cdysthe
06-30-2013, 12:03 PM
You need to put at least 35 front and rear for better daily performance and mileage.
My tpms doesn't work when I first start , but is all right as I drive a few 10th's of a Mile.

Okay, I will put 40 front, 38 rear to see how that works. I get a specific error message telling me the TPMS isn't available, the TPMS warning light keeps flashing for a while and then turns off. Does that mean it suddenly starts working again for some reason?

Felnus
06-30-2013, 12:45 PM
Okay, I will put 40 front, 38 rear to see how that works. I get a specific error message telling me the TPMS isn't available, the TPMS warning light keeps flashing for a while and then turns off. Does that mean it suddenly starts working again for some reason?

Someone correct me if I'm wrong but if the warning light stops flashing, the system should be working correctly.

Abarth Phreak
06-30-2013, 02:00 PM
Someone correct me if I'm wrong but if the warning light stops flashing, the system should be working correctly.

That is my understanding also, it is apparently programmed to signal when an error is actually occurring. Hence the need to take it to the dealer when actually lit.

cdysthe
06-30-2013, 02:25 PM
That is my understanding also, it is apparently programmed to signal when an error is actually occurring. Hench the need to take it to the dealer when actually lit.

If that's the case it's going to be hard to show it to the dealer since it only happens when I start the car after it has been standing for at least an hour. Then it happens once and sometimes twice, but the flashing light always goes out after a minute or so. I would have to take it to the dealer, have them leave the car for a couple of hours and then try and start it. That would be the only way for me to "prove my point". I wish there was some kind of log of events like this so I didn't have to go through all that. The alternative is to ignore it, but I do not like to have to look at an error message on new car almost every time I start it.

I did raise the pressure to 40/38. No error message so far today, but it's much cooler outside and it never happens unless it's over 100F.

pastor passum
06-30-2013, 07:03 PM
While I'm not sure if increasing your air pressure will fix your TPMS issues, I'm certain your fuel economy will improve and your 500 will handle better. Good luck.

Abarth Phreak
07-01-2013, 12:37 AM
If that's the case it's going to be hard to show it to the dealer since it only happens when I start the car after it has been standing for at least an hour. Then it happens once and sometimes twice, but the flashing light always goes out after a minute or so. I would have to take it to the dealer, have them leave the car for a couple of hours and then try and start it. That would be the only way for me to "prove my point". I wish there was some kind of log of events like this so I didn't have to go through all that. The alternative is to ignore it, but I do not like to have to look at an error message on new car almost every time I start it.

I did raise the pressure to 40/38. No error message so far today, but it's much cooler outside and it never happens unless it's over 100F.

I think I misread or misunderstood this issue. The light goes out shortly after starting the car correct? If so, the system is working properly. The "Tire !" symbol (telltale) will stay on if the sensor detects under-inflated tires while the TPMS light is the systems status check. It will go through a communication mode during start-up, possibly a quick second and as much as a few minutes depending on speed of signal strength, then turn off after the system checks-out okay. If it stays lit you have an issue. If it is going off after starting, you are fine. I meant in my earlier post that if it stays lit to go see the dealer because there is a problem. You can also refer to your manual for more info on how the TPMS system works. I am not sure if the Abarth manual reads verbatim to the standard 500s so I opted not to include it directly here. I hope this helps more.

Evelyn Salt
07-01-2013, 09:48 AM
Okay, I will put 40 front, 38 rear to see how that works. I get a specific error message telling me the TPMS isn't available, the TPMS warning light keeps flashing for a while and then turns off. Does that mean it suddenly starts working again for some reason?
Evidently. As long as the light goes out ,I'm sure it's working , and am not going to
Worry about it, just check tire pressure regularly

ciddyguy
07-01-2013, 08:32 PM
Another thing, pretty much all cars since the days of the idiot light (former term for such lights), all had a bulb check routine to ensure nothing's burned out, and they do this by lighting all lamps and you see, and note which ones light, or don't, and thus if a crucial bulb is out, say the malfunction engine light (MEL, formerly known as the Check Engine Light [CEL]), then you need to get it to someone who can replace the bulb for you.

This is normal, it's when the light comes on, stays on, or flickers, such as the oil light on some very old cars at idle, it's an indication you have low oil pressure. Now, most cars most cars today rely on an oil light, and battery light, but give you a temp gauge, and the gas gauge, but the "idiot" light is now much more sophisticated than it ever had been, thanks to displays, such as the EVIC to tell you exactly what's wrong.

But since you say it's going out after a short period, and stays out, then your system is more or less functioning properly.

Good luck.

cdysthe
07-01-2013, 08:49 PM
Another thing, pretty much all cars since the days of the idiot light (former term for such lights), all had a bulb check routine to ensure nothing's burned out, and they do this by lighting all lamps and you see, and note which ones light, or don't, and thus if a crucial bulb is out, say the malfunction engine light (MEL, formerly known as the Check Engine Light [CEL]), then you need to get it to someone who can replace the bulb for you.

This is normal, it's when the light comes on, stays on, or flickers, such as the oil light on some very old cars at idle, it's an indication you have low oil pressure. Now, most cars most cars today rely on an oil light, and battery light, but give you a temp gauge, and the gas gauge, but the "idiot" light is now much more sophisticated than it ever had been, thanks to displays, such as the EVIC to tell you exactly what's wrong.

But since you say it's going out after a short period, and stays out, then your system is more or less functioning properly.

Good luck.

Note that I also get a message in the display saying something like "Tire pressure monitoring is not available". The text scrolls by a couple of times while the light is blinking. Then the text disappears but the blinking light continues for a minute or so before it goes out. You still think it's working properly? Anyhow, regardless of whether it is working or not I would like for that error message to go away unless something really is wrong. It reminds me too much of all the messages I got through the years driving Citroens, Renaults, Peugeots and Fiats back in Europe. I was hoping they had fixed this kind of thing before they sent Fiat back to the US. Coming from a trusty old Toyota Corolla I'm not used to stuff not working correctly, but I had also forgotten that driving could be fun :)

zyxelenator
07-02-2013, 12:37 AM
I have a same problem. Tpms unavailable lights up, then goes away in 30 sec after start. I just came back from dealer. They said all sensors read good, they replaced receiver box today. And error came back after couple hours sitting. I heard one theory some time ago and will check it. Do you guy have metal aftermarker valve caps by any chance? Or other than stock? I do. I installed metal red caps with fiat logo, and I think it started doing it after that. The theory is, that metal part of the valve acting as antenna for tpms system, and everything other than thin plastic cap will interferece the signal. I will put stock caps again and see what happens.

cdysthe
07-06-2013, 05:25 PM
So I raised the tire pressure to 40/38 a week or so ago and haven't had any error messages from TPMS regardless of temperature! Last night I lowered it again to 32/30 and I just got the error message again! Why on earth doesn't it work when I use the recommended tire pressure? Recommended as in Fiat recommended. In this forum I got using 40 recommended so I did. I like the handling of the car much better with 40/38 so i will keep it that way, but it still puzzles me that lowering it causes TPMS to consistently malfunction.

Abarth Phreak
07-06-2013, 11:37 PM
So I raised the tire pressure to 40/38 a week or so ago and haven't had any error messages from TPMS regardless of temperature! Last night I lowered it again to 32/30 and I just got the error message again! Why on earth doesn't it work when I use the recommended tire pressure? Recommended as in Fiat recommended. In this forum I got using 40 recommended so I did. I like the handling of the car much better with 40/38 so i will keep it that way, but it still puzzles me that lowering it causes TPMS to consistently malfunction.

Its not an exact science...lol. Glad it is working for you though.

redred
07-07-2013, 10:33 AM
Had the exact same error on my Abarth yesterday. Started the car and it gave me the warning that the TPMS was unavailable and the yellow warning light in the top right corner was flashing. Went away about 5 min later.

It wasn't that hot here either. It was only 88 degrees. Last weekend at Streets of Willow it was 112 degrees and I didn't have the issue.

I do, however, have aftermarket wheels (BF Goodrich Sport Comp 2's)

Tb Pfeirico
08-24-2013, 12:37 AM
Just had my car into the shop for 6 week with the same problem.. i have a warranty and refused to accept my car back until it was fixed. Drove the dealer crazy trying to fix it.. but he did.. He said it was a sensor in one of the tires. fiat corp kept telling them to replace and reprogram everything . none of it worked.. it was his last thing he had to try and it worked..

ShooterBobSC
02-08-2015, 11:17 AM
Just had my car into the shop for 6 week with the same problem.. i have a warranty and refused to accept my car back until it was fixed. Drove the dealer crazy trying to fix it.. but he did.. He said it was a sensor in one of the tires. fiat corp kept telling them to replace and reprogram everything . none of it worked.. it was his last thing he had to try and it worked..

Good for you! I ended up buying 4 new wheels and tires from Tire Rack and it solved mine. It's been not working since 27,000. Evidently I had a bad unit in one of the old wheels.

lenpelly
07-17-2015, 01:15 PM
I get the same message "Tire pressure monitoring is not available" with the light blinking for a while then the light stays on. I was hoping that someone else had run into this problem and found a solution other than taking it to the dealer. The nearest dealer to me is about a 2 hour drive one way.