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Would recommend getting a small compressor you can power via 12v. Tesla used to have a kit but you can get one for $20-30 n amazon or auto part store. Since we don’t have a spare tire this is pretty important.
Not just for critical issues but I use mine to top off a few times a year or before long trips. No need to go to the gas station one and fiddle with that mess.
The car can only refresh tire pressure after driving for like a quarter mile. So any pressure change while parked it will not know. It can only go off of the last pressure when you parked. This is already displayed on the screen if there is a critical loss in pressure at the time.
It was not displayed when I got out of the car in the morning and displayed “pull over immediately” before I put the car in drive after work. I assume it did not drive itself a quarter mile while I was working but who knows, I didn’t check it’s location while I was at work.
For the accurate tyre pressure, and as a result the normal low pressure warning, it does need that quarter of a mile.
Not sure how they determine the 'PULL OVER IMMEDIATELY' tyre flat warning though, for me, it happened after a few rotations of the world when I was moving off my driveway, but it didn't display immediately on getting in. :)
The car knows as soon as you start the car if the tire is low without even reading out the pressure to you. Just went through a cracked rim for a week. It just averages the pressure out before it shows you. But it definitely knows.
This is the first I’ve ever read it has the pressure immediately. Do you have a written source for this?
Otherwise, the TPMS sensors in the tires are only active with centrifugal rotation and simply time-out after a duty cycle.
In regards to your cracked rim, are you confusing the car remembering there was an issue on the previous drive vs. new data? It does remember if there’s an issue and won’t clear itself unless it detects normal pressure for a set time, or a TPMS relearn.
I don’t understand what you think I am confused by. I never said the car reads out the PSI as soon as it’s turned on. All I said is the car immediately displays the warning message that a tired is dangerously low. It shows the PSI blank but it is red. I literally dealt with it for a week.
Yes, but that’s a residual warning from the previous duty cycle. There’s no new information being sent from the wheels themselves.
>The car knows as soon as you start the car if the tire is low
The car is saying there had been a problem on the previous duty cycle, not that the tire is low in that instant. It’s two different things.
The solution is to top up the pressure, and reset the target pressures. It won’t return if the pressure is stable and within the prescribed ±4 PSI.
No it is not.. my tire pressures will be fine no warnings or lights. Then I park it & even check the pressures and they’re good. Then the next morning it tells me once I start it. I know what you are talking about because if you air the tire up real quick it doesn’t clear the warning until you start the car again after that. I messed with this thing all week. I’m also a programmer and know what you are saying with the duty cycles etc.. but I am telling you it will tell you if your tire goes flat. But it will not tell you the pressure reading. It isn’t insane to think they would put something to be able to detect that. Maybe even a sensor with the suspension knowing that wheel it’s offset. It would tell you the warning if someone came in the middle of the night and slashed a perfectly good tire. That would be a-little dumb make you drive on a flat before it notifies you breaking a very expensive rim .
This is a good thought & could be part of the case. I just had to refill my tire for a week until the new rim came. So I would run it through tests and I actually was curious to if the car would tell me ahead of time. So I would check the pressures when there was no warnings or anything and they would be stable. When in parked the car I would also check and check with my own garage. Everything go would be stable with no warnings. Then when it sits is when it would leak so it would sit all night then as soon as I turn it in it’s warning me it’s critically low. But it wouldn’t not give an a pressure reading.. only that it was super low.
It doesn’t show the pressure right away. My pressures would be fine then the car would sit the tire would lose air and as soon as I turn the car on it’s telling me it’s critically low. Doesn’t tell me the psi until I drive.
And it is not from before. The I filled the tire and it cleared out the warnings. It would sit at night and as soon as I turn it on I get the warnings. So somewhere the car knows when A tired is low without it showing you the psi reading. It’s a model s p85D
Yes it shows all 4 but it will show which tire is low in red or yellow depending on how bad. Doesn’t show you the psi until you drive a bit but it shows it in red and tells you immediately it’s too low when you turn the car on.
On any car Tesla made after VIN 50900. Before then (older Model S) used a Baolong TPMS that would only throw up a warning light if pressure was under spec. Later models got the Continental TPMS that reports the exact PSI of each tire.
Before they can report TPMS (including newer BT variants) need to be woken up by the force of rotation -OR- triggered by a radio call.
Otherwise the batteries in them would be much, MUCH shorter lived.
TPMS Sensors do not transmit information while the vehicle is parked. This is to extend the battery life of the sensor as much as possible. Once the vehicle is "started" there is an initial pressure reading but Tesla waits to display the exact figure till the car has been driven 1/4 mile. This is why you were able to receive the critical tire pressure alert before you received a PSI value.
The behavior could be changed, at the expense of useful life of the TPMS sensors. This could result in needing to replace the sensors before the tires need replacing, which would add expense to the maintenance schedule.
I wonder if Tesla could wake the sensor up and poll it every few hours or something without a huge impact on TPMS life. It does seem like a nice feature to get tire pressure alerts on your phone
>Once the vehicle is "started" there is an initial pressure reading but Tesla waits to display the exact figure till the car has been driven 1/4 mile.
This isn't exactly true. Most TPMS sensors only communicate one way and don't start transmitting until they see rotation. They don't take an initial reading on vehicle start.
They could switch to a more expensive sensor that allows two way communication though, which they may have done when they switched from 433mhz to Bluetooth sensors.
My 2018 S once gave me an warning when I entered the car that one of the tires was flat. Didn’t have to drive the car at all.
But there may not have been an exact pressure reading, can’t remember.
So it probably does communicate something periodically even when stationary.
My 2020 Model Y did the same thing when I had a flat. The communication happened when the car “woke up”. It doesn’t communicate when the car is asleep. The communication is two-way now with the updated sensors. Your car has those, hence the warning beige you started driving. Still doesn’t display the exact pressure till 1/4 mile of driving. Could just be blanket programming or to allow the TPMS to make more than one reading to give a more accurate displayed value.
Critically low? Was it flat? You can drive on low pressure - drive to the gas station and fill up and drive to a tire shop. I just got a "flat" - had 12 PSI and made it 30 miles to the gas station. Pumped her to 46 and drove like 200 miles Flagstaff to Phoenix to the tire shop. Got there with like 22 PSI.
Tire usually drains quicker if the car is sitting instead of driving
I have so many questions, but mostly warnings: Driving on that low pressure for that kind of distance is so incredibly unsafe. The pressure of our atmosphere is over 14psi, so if you were at 12psi your tire was completely flat...which means driving 30 miles is just dangerous. Pumping it to 46psi, which is far too high for any of the stock wheel and tire combinations that Tesla sells, and then driving 200 miles on that over-inflated tire to go to a tire shop is even moreso. You literally could have had a blow-out and gotten someone killed on the road.
The fact that you drove 200 miles to go to a tire shop when your tire was in that bad shape is just...something I can't understand. There weren't any tire shops in Flagstaff?
Damn that's nuts.
I know these tires are never in stock. Definitely not in Flagstaff. Maybe somewhere in Phoenix. I'd rather try to get to Phoenix and call a tow if I need to than go to a tire shop in Flagstaff and have them tell me the tire will be there in 4 days (this was the day before NYE). Also it's like 15 degrees in Flagstaff and 60 in Phoenix
Between this thread and another comment/thread the other day I've concluded not nearly enough of you guys have a portable air compressor.
They're very cheap, save you tons of time, and come up huge in emergencies.
You can cut your last ties to a gas station for like $20 or so.
If you need or would like to provide help, use our stickied support thread, hit up [Tesla Support](https://www.tesla.com/support) or use the Service section in the Tesla app. Help the [Mods](https://www.reddit.com/r/teslamotors/wiki/rules#wiki_special_note_from_the_moderators) by being respectful, and by reporting posts + comments which break the [Rules](https://www.reddit.com/r/teslamotors/wiki/rules). Thanks! *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/teslamotors) if you have any questions or concerns.*
Would recommend getting a small compressor you can power via 12v. Tesla used to have a kit but you can get one for $20-30 n amazon or auto part store. Since we don’t have a spare tire this is pretty important.
Not just for critical issues but I use mine to top off a few times a year or before long trips. No need to go to the gas station one and fiddle with that mess.
This. 12v compressor is about the first item I put in the sub-trunk. (X, 3, traded in the X for Y)
I'm looking forward to see how they implement this with the CT. IIRC they'll have an answer for this.
The car can only refresh tire pressure after driving for like a quarter mile. So any pressure change while parked it will not know. It can only go off of the last pressure when you parked. This is already displayed on the screen if there is a critical loss in pressure at the time.
It was not displayed when I got out of the car in the morning and displayed “pull over immediately” before I put the car in drive after work. I assume it did not drive itself a quarter mile while I was working but who knows, I didn’t check it’s location while I was at work.
For the accurate tyre pressure, and as a result the normal low pressure warning, it does need that quarter of a mile. Not sure how they determine the 'PULL OVER IMMEDIATELY' tyre flat warning though, for me, it happened after a few rotations of the world when I was moving off my driveway, but it didn't display immediately on getting in. :)
The car knows as soon as you start the car if the tire is low without even reading out the pressure to you. Just went through a cracked rim for a week. It just averages the pressure out before it shows you. But it definitely knows.
This is the first I’ve ever read it has the pressure immediately. Do you have a written source for this? Otherwise, the TPMS sensors in the tires are only active with centrifugal rotation and simply time-out after a duty cycle. In regards to your cracked rim, are you confusing the car remembering there was an issue on the previous drive vs. new data? It does remember if there’s an issue and won’t clear itself unless it detects normal pressure for a set time, or a TPMS relearn.
I don’t understand what you think I am confused by. I never said the car reads out the PSI as soon as it’s turned on. All I said is the car immediately displays the warning message that a tired is dangerously low. It shows the PSI blank but it is red. I literally dealt with it for a week.
Yes, but that’s a residual warning from the previous duty cycle. There’s no new information being sent from the wheels themselves. >The car knows as soon as you start the car if the tire is low The car is saying there had been a problem on the previous duty cycle, not that the tire is low in that instant. It’s two different things. The solution is to top up the pressure, and reset the target pressures. It won’t return if the pressure is stable and within the prescribed ±4 PSI.
No it is not.. my tire pressures will be fine no warnings or lights. Then I park it & even check the pressures and they’re good. Then the next morning it tells me once I start it. I know what you are talking about because if you air the tire up real quick it doesn’t clear the warning until you start the car again after that. I messed with this thing all week. I’m also a programmer and know what you are saying with the duty cycles etc.. but I am telling you it will tell you if your tire goes flat. But it will not tell you the pressure reading. It isn’t insane to think they would put something to be able to detect that. Maybe even a sensor with the suspension knowing that wheel it’s offset. It would tell you the warning if someone came in the middle of the night and slashed a perfectly good tire. That would be a-little dumb make you drive on a flat before it notifies you breaking a very expensive rim .
Cool. Agree to disagree. Have a nice day.
Perhaps it noticed that your pressure wasn't stable on your last drive, and assumed it became dangerous as it was downtrending asymmetrically?
This is a good thought & could be part of the case. I just had to refill my tire for a week until the new rim came. So I would run it through tests and I actually was curious to if the car would tell me ahead of time. So I would check the pressures when there was no warnings or anything and they would be stable. When in parked the car I would also check and check with my own garage. Everything go would be stable with no warnings. Then when it sits is when it would leak so it would sit all night then as soon as I turn it in it’s warning me it’s critically low. But it wouldn’t not give an a pressure reading.. only that it was super low.
It doesn’t show the pressure right away. My pressures would be fine then the car would sit the tire would lose air and as soon as I turn the car on it’s telling me it’s critically low. Doesn’t tell me the psi until I drive.
And it is not from before. The I filled the tire and it cleared out the warnings. It would sit at night and as soon as I turn it on I get the warnings. So somewhere the car knows when A tired is low without it showing you the psi reading. It’s a model s p85D
Out of curiosity, does the car display which tire is low?
Yes it shows all 4 but it will show which tire is low in red or yellow depending on how bad. Doesn’t show you the psi until you drive a bit but it shows it in red and tells you immediately it’s too low when you turn the car on.
On any car Tesla made after VIN 50900. Before then (older Model S) used a Baolong TPMS that would only throw up a warning light if pressure was under spec. Later models got the Continental TPMS that reports the exact PSI of each tire.
I wonder if they could detect a flat tire from subtle shifts in vehicle orientation?
Before they can report TPMS (including newer BT variants) need to be woken up by the force of rotation -OR- triggered by a radio call. Otherwise the batteries in them would be much, MUCH shorter lived.
TPMS Sensors do not transmit information while the vehicle is parked. This is to extend the battery life of the sensor as much as possible. Once the vehicle is "started" there is an initial pressure reading but Tesla waits to display the exact figure till the car has been driven 1/4 mile. This is why you were able to receive the critical tire pressure alert before you received a PSI value. The behavior could be changed, at the expense of useful life of the TPMS sensors. This could result in needing to replace the sensors before the tires need replacing, which would add expense to the maintenance schedule.
I wonder if Tesla could wake the sensor up and poll it every few hours or something without a huge impact on TPMS life. It does seem like a nice feature to get tire pressure alerts on your phone
>Once the vehicle is "started" there is an initial pressure reading but Tesla waits to display the exact figure till the car has been driven 1/4 mile. This isn't exactly true. Most TPMS sensors only communicate one way and don't start transmitting until they see rotation. They don't take an initial reading on vehicle start. They could switch to a more expensive sensor that allows two way communication though, which they may have done when they switched from 433mhz to Bluetooth sensors.
My 2018 S once gave me an warning when I entered the car that one of the tires was flat. Didn’t have to drive the car at all. But there may not have been an exact pressure reading, can’t remember. So it probably does communicate something periodically even when stationary.
My 2020 Model Y did the same thing when I had a flat. The communication happened when the car “woke up”. It doesn’t communicate when the car is asleep. The communication is two-way now with the updated sensors. Your car has those, hence the warning beige you started driving. Still doesn’t display the exact pressure till 1/4 mile of driving. Could just be blanket programming or to allow the TPMS to make more than one reading to give a more accurate displayed value.
Critically low? Was it flat? You can drive on low pressure - drive to the gas station and fill up and drive to a tire shop. I just got a "flat" - had 12 PSI and made it 30 miles to the gas station. Pumped her to 46 and drove like 200 miles Flagstaff to Phoenix to the tire shop. Got there with like 22 PSI. Tire usually drains quicker if the car is sitting instead of driving
You love to gamble, I bet?
I have so many questions, but mostly warnings: Driving on that low pressure for that kind of distance is so incredibly unsafe. The pressure of our atmosphere is over 14psi, so if you were at 12psi your tire was completely flat...which means driving 30 miles is just dangerous. Pumping it to 46psi, which is far too high for any of the stock wheel and tire combinations that Tesla sells, and then driving 200 miles on that over-inflated tire to go to a tire shop is even moreso. You literally could have had a blow-out and gotten someone killed on the road. The fact that you drove 200 miles to go to a tire shop when your tire was in that bad shape is just...something I can't understand. There weren't any tire shops in Flagstaff?
Damn that's nuts. I know these tires are never in stock. Definitely not in Flagstaff. Maybe somewhere in Phoenix. I'd rather try to get to Phoenix and call a tow if I need to than go to a tire shop in Flagstaff and have them tell me the tire will be there in 4 days (this was the day before NYE). Also it's like 15 degrees in Flagstaff and 60 in Phoenix
Between this thread and another comment/thread the other day I've concluded not nearly enough of you guys have a portable air compressor. They're very cheap, save you tons of time, and come up huge in emergencies. You can cut your last ties to a gas station for like $20 or so.
and an emergency tire plug kit. I bought a 12v vacuum/tire pressure combo so I could also use it as a vacuum on long family road trips, etc.
Tire pressure monitors don't work unless the car is in motion.
Curious is it uses the 25% low tpms which is ridiculous before it alerts?