tyre pressure

[sceh]

MY 2022
This morning I suddenly have a tyre pressure warning light. It reads 2.6 bar on all tyres but on the display the drivers side tyre warning is white and on the passenger side, orange. The last time I saw any warning was when it was freezing months ago but the tyres warmed up and it went.
After driving ten miles, the light is still on but the pressures are now 2.7 bar;
How come the car thinks all four tyres have suddenly dropped to 2.6 - all of them? Seems like a bug to me since all the tyres are at 2.9 according to my pressure gauge.
Any ideas please?
thanks

 

[ewoodrick]

MY 2022
This morning I suddenly have a tyre pressure warning light. It reads 2.6 bar on all tyres but on the display the drivers side tyre warning is white and on the passenger side, orange. The last time I saw any warning was when it was freezing months ago but the tyres warmed up and it went.
After driving ten miles, the light is still on but the pressures are now 2.7 bar;
How come the car thinks all four tyres have suddenly dropped to 2.6 - all of them? Seems like a bug to me since all the tyres are at 2.9 according to my pressure gauge.
Any ideas please?
thanks

And what do the tire pressures indicate if you measure them manually?

Also remember that tire pressures should only be measured when the tires are at ambient temperature. Tire pressures will go up as the tires get hot.

 

[sceh]

Sorry for the confusion. When I measured them manually they are 2.9 (all four) but the TPMS says they are at 2.6

 

[ewoodrick]

And you measured cold? How accurate is your gauge?

May be time for a Service Ticket.

 

[sceh]

I will ping them and they may be able to fix it over the air. I also have the silent turn-signal issue..

 

[ewoodrick]

I will ping them and they may be able to fix it over the air. I also have the silent turn-signal issue..

Have you rebooted lately?

 

[dafish]

I suspect you hand gauge is off.

in my experience the warnings split by severity. I suggest at some point, perhaps during the night, one side read just enough lower To be more severe.

 

[sceh]

I think a new gauge would be in order anyway so I will try first an no, I have never rebooted because I am sot sure what to do since there are soft reboots, hard reboots and another that escapes me. Which should I tackle first?

 

[ewoodrick]

Press and hold the two steering wheel buttons until the screen goes dark.

It is scary the first time, but this can actually be done with the car in motion and FSD engaged. You just don't see or hear anything during a reboot.

 

[sceh]

Bought a new gauge and indeed the old gauge is inaccurate by 15%!
I still don't know why it said all was ok for months and then suddenly all four tyres are low pressure. Ah well..

 

[sceh]

So, pumped up the tires to 2.9 and went for a drive. AFter ten minutes the warning light went out as expected. The tire pressures were shown as 2.8 and then one only rose to 2.9! The wheels on the right hand side were shown white and the left, orange.

So, questions:

Why does the car say 2.8 when I know it is 2.9?
What is the tolerance on the readings? Would 2.85 read as 2.8 or 2.9?
Does the system show the warning when the absolute pressure is less that recommended or does it show when there is an imbalance -left/right or front/back or when ONE is out by a certain amount in comparison with the others?
Why does it display some tires white and others orange?

Thanks for any insight here!

 

[sceh]

So, this morning the pressures read 2.7 on the driver's side and 2.8 on the passenger side - both white and there is no way they all lost pressure from 2.9 yesterday.
There is something amiss with the TPMS and sensor reading software for sure since other report oddities. Any way of getting attention from Tesla about this?

 

[Goobers]

So, this morning the pressures read 2.7 on the driver's side and 2.8 on the passenger side - both white and there is no way they all lost pressure from 2.9 yesterday.
There is something amiss with the TPMS and sensor reading software for sure since other report oddities. Any way of getting attention from Tesla about this?

Was the ambient air temperature cooler in the morning than when you pumped up the tires the day before?

As for your other posts... honestly, its folly to try to pin down why this or why that between two different pressure sensors.

The oldest, truest recommendation is simply, if you're going to take measurements, stick to ONE device. Different devices have different calibrations. And as you've already seen for yourself, a given device can be wrong/mis-calibrated.

Make a chart for your handheld gauge and then the TPMS numbers and see how the numbers change. If they both show similar changes (which they should), then even if they don't have the exact same number as each other, it's simply a matter of calibration.

So don't worry about it... cause even if you do, there's nothing anyone can do other than open up your handheld gauge and twist the needle to match the tpms.

Reminds me of the phrase my friend once quoted... much ado about nothing.

 

[sceh]

Same temperature. I am just curious as to why it is not accurate. I will ping tesla and see if they know.
rgds

 

[jcanoe]

Always check the tire pressure when the vehicle has not been driven for at least several hours, out of direct sunlight. Early A.M. is usually best for checking tire pressure. The heat from the sun's rays will cause a slight rise in tire pressure on the side of the parked vehicle facing towards the sun. If you park close to a building that side may be warmer and the tire pressure may read slightly higher on the side closest to the building.

In my experience the Tesla TPMS sensors are accurate to within +/- 1 PSI (0.07 bar) Use a good quality tire pressure gauge to check, adjust the tire pressure. Tire pressure readings can increase up to 3 PSI (0.21 bar) after being driven on the highway, even a bit more in summer. This is normal. Do not adjust the tire pressure when the tires are warm from driving. Seasonally you should check and adjust the tire pressure; add air to the tires in fall heading into winter. Reduce tire pressure by a corresponding amount in spring once the temperature warms.

 

[sceh]

much ado about nothing.

Maybe and maybe not. The pressure gauge is new and certified and I also compared it with another gauge (not my old one which is duff) and both give the same reading and they both differ from what the car says. Apart from being annoying, it is potentially dangerous. I doubt it is the pressure sensors in the wheels and I have made sure there are no USB devices near the centre console so it is somewhere in the ECU logic. I will make sure I have the most recent software and if it persists after a long drive I will raise it to the local Tesla dealer.

As for danger, suppose the car reads high and says the tires are OK when they aren't? Ever driven a car with the rear tires a bit flat? Like skating on ice

 

[Dangerous Fish]

Maybe and maybe not. The pressure gauge is new and certified and I also compared it with another gauge (not my old one which is duff) and both give the same reading and they both differ from what the car says. Apart from being annoying, it is potentially dangerous. I doubt it is the pressure sensors in the wheels and I have made sure there are no USB devices near the centre console so it is somewhere in the ECU logic. I will make sure I have the most recent software and if it persists after a long drive I will raise it to the local Tesla dealer.

As for danger, suppose the car reads high and says the tires are OK when they aren't? Ever driven a car with the rear tires a bit flat? Like skating on ice

"Certified" by who? What are the makes/models? Unless you have a gauge properly calibrated against a known true pressure, you could have two duff gauges there. Even relatively expensive pressure gauges can be faulty/out of calibration.

If your gauges were made in China and come with a "calibration certificate", that's no guarantee the readings are accurate, believe me. You might also want to try taking several readings over time and seeing how consistent the readings are (bearing in mind that each time you take the gauge off the valve you'll lose a small amount of air).

You're also ignoring the 'rounding' errors that are always there with the TPMS system. The display shows 2.8 bar but that could be anything from 2.76-2.84 bar. That's a >1psi spread and as said TPMS sensors can be out by 1psi easily (mine are) so there's a potential >2psi discrepancy between 'actual' pressure and the number the car gives you.

At the end of the day, the TPMS system just reports the numbers the sensors send and it's extremely unlikely that 4 sensors on the same car are all faulty and under/over reading by a large amount. In any case, a 1-2psi variation from the target pressure is not going to be dangerous, but if you really are concerned about that find someone with a recently calibrated gauge (all good service centres should get their equipment calibrated regularly by a UKAS/BSI approved service) and compare the TPMS figures against their gauge so you then have an offset you can apply.

Or just don't worry about it and get on with life

 

[Goobers]

As for danger, suppose the car reads high and says the tires are OK when they aren't? Ever driven a car with the rear tires a bit flat? Like skating on ice

A bit flat is skating on ice...? And rather than skating on ice, maybe you mean sliding on ice? I don't know about you, but skating on ice is very easily controllable. I've gone skating on ice plenty of times. Now that I've thought about it, skating on ice is almost like a train on rails... the skates make you go in the direction they're pointing. You're not randomly sliding around.

I have driven with a FULL FLAT on the highway at full speed (70 mph)... so yeah, I've gone through stuff.

You, on the other hand, look like someone making a big fuss over nothing.

That said... time to ignore this thread.

 

[sceh]

70 mph with a flat rear? No you haven't because you wouldn't be alive to tell the tall tale.
Fuss over nothing? So all the manufacturers in the world are wrong when they recommend tire pressures and YOU are right?
ANyone have a pointer to a technical forum on Tesla where people know what they are talking about by chance??

 

[Goobers]

70 mph with a flat rear? No you haven't because you wouldn't be alive to tell the tall tale.
Fuss over nothing? So all the manufacturers in the world are wrong when they recommend tire pressures and YOU are right?
ANyone have a pointer to a technical forum on Tesla where people know what they are talking about by chance??

Okay, so I'll respond to this one.

You said it yourself... its a RECOMMENDED pressure, not required.

If you can understand the difference between the two, in relation to tire pressures, you should understand why it is you're making a big fuss over nothing.