Low pressure tyre warning

[olliewebb]

Oh Ollie Ollie Ollie?‍
What did you do? ?

"Here's how you can save around 5+ hours a week by doing it a new way - using the newer features in version of the software you already have and use daily"

[MUCH FROWNING]

 

[AB71]

"Here's how you can save around 5+ hours a week by doing it a new way - using the newer features in version of the software you already have and use daily"

[MUCH FROWNING]

Nowt wrong with that mate

 

[tsedge]

Well... this is a thread that I won't ever get the time back after wading through 3 pages! ?

 

[olliewebb]

Well... this is a thread that I won't ever get the time back after wading through 3 pages! ?

Yep that's how time works.

 

[AB71]

Well... this is a thread that I won't ever get the time back after wading through 3 pages! ?

Ay we all have to read some ? on here at times tbf

 

[goose]

Hello Team,
Just wondering if anyone has experienced a tyre pressure warning message?
I have had this happen a handful of times recently and although upon checking, it seems like a false alarm, I am concerned that it can condition the driver into thinking all alarms can be ignored. The only 'explanation' given me is that the system is soooo sensitive that any slight change in tyre pressure can cause this. Sounds a bit dodgy to me though and bit like the stuff that comes out of the back of a male bull.
Any feedback would be appreciated. I enclose a photo for reference (taken when standing still by the way).

 

[fnegroni]

what do you mean by ‘upon checking this seems a false alarm’?
Are you saying your tyres are at the recommended 2.5bar when cold but the system is reporting incorrect tyre pressures?
Did you consciously set the tyres at 2.3bar? If so why? If not, please inflate them to the recommended 2.5bar

 

[Martinonline]

Yes, I had it last Sunday when the weather turned cold. I just put some more air in and the warning went away.

 

[goose]

Thanks for the reply, no, I didn't set the tyres to 2.3 bar and I have noticed that the reported pressure is subject to some normal variation. I guess this is not totally unexpected given that cold tyre pressure and warm tyre pressure will differ.

'Upon checking this seems a false alarm' means that farther into the journey, the warning light went out and the system was 'happy'. So, why does it pick out one and later two tyres when the pressure across all 4 is roughly the same?

Once the tyres are cold and this storm passes (raining 'cats and dogs' at the moment) then I do plan to check them and make any adjustments neccesary (this is part of my regular routine anyway)

But, to get back to my original question, are others experiencing issues with the tyre warning system?

 

[Martinonline]

Please use the search function and you will see many posts on this subject.

 

[goose]

Thanks Martinonline, I have been down that road (no pun intended). Hopefully that will do the trick for you, but if it doesn't perhaps you would let me know. I have driven many cars in my time and only once did I have this kind of message on any of them and that was when I had a slow puncture!

 

[Rolfe]

I've just merged about four threads started in the recent past about this same issue, in the hope we can keep all the useful hints and tips in one place.

Reading through the merged thread will answer a lot of queries, often in triplicate! (Plus a rather fun derail about filling tyres with nitrogen gas.)

 

[goose]

I think you answered your own question really: roughly the same isn’t the same.
And roughly 2.4 bar could mean 2.35 bar which could also mean 2.34 bar for a few seconds and then 2.4
Basically the system works as designed: if your cold tyre pressure is too low, it will warn you
So 2.4 bar with a warning and 2.4 bar without a warning are not the same 2.4bar: the one with the warning is lower (eg 2.35) and that’s below the recommended.

It’s a warning: if you know your tyres are fine after driving a short while, accept it.
Although just ‘putting a bit of air in it’ isn’t really filling me with confidence that you hit the right pressure.
I consciously keep mines at 35 psi all round (just above 2.4 bar). And when the weather changes by more than 10C I check and deflate/reinflate accordingly. Yes I’m picky about tyre pressure.

GT3 drivers get this all the time: a low tyre pressure warning means ‘go easy on the kerbs and put some heat in those tyres by driving more aggressively’

If I were a GT3 driver then I might well accept it, but I am driving an MG 4 production car meant for driving by ordinary motorists!
By the way, I have driven a great number of cars in my time and many of them with tyre pressure warning systems. I have never come across a production vehicle that is so picky and devoid of logic in this respect. I do have difficulty accepting that the system will report first one and later two tyres at 2.3 bar when a third is at 2.3 bar and reported as OK. The final, front, tyre (see my photograph) is at 2.4. So as I see it, if the system should report on a tyre pressure issue it should have highlighted the odd one out at 2.4?
By the way, if I accept your logic, then it becomes nearly impossible to get the correct pressure into any car, given the pressure at 2.4 may mean 2.35 or 2.34, so how do you add air to any tyre and trust that the gauge is correct? Further, 'How do you know that the tyres are fine after driving for a short while' and accept it? - that way leads to acceptance of slow punctures and potential consequences sneaking up. It seems that if a system is incorporated into a vehicle and classed as a driver warning then it should work consistently and follow some logic. Otherwise don't have it.

 

[goose]

Rolfe,
I accept your comment re - not checking for existing threads. I should have done so and I apologise. A novice mistake made honestly by a novice member. I hope I haven't wasted too much of the forums time. Sorry folks!!

 

[Rolfe]

Rolfe,
I accept your comment re - not checking for existing threads. I should have done so and I apologise. A novice mistake made honestly by a novice member. I hope I haven't wasted too much of the forums time. Sorry folks!!

It's OK! We can always merge threads. No need to apologise.

I should probably have merged these earlier ones sooner. It was only when we got to the count of four I thought, hey, this needs consolidating.

I see that the post I was replying to - a question about how could we keep all this stuff together to save multiple threads being created - has now been wiped, so I'll just delete it and my reply. But don't apologise, it happens all the time and it's not a problem.

 

[fnegroni]

If I were a GT3 driver then I might well accept it, but I am driving an MG 4 production car meant for driving by ordinary motorists!
By the way, I have driven a great number of cars in my time and many of them with tyre pressure warning systems. I have never come across a production vehicle that is so picky and devoid of logic in this respect. I do have difficulty accepting that the system will report first one and later two tyres at 2.3 bar when a third is at 2.3 bar and reported as OK. The final, front, tyre (see my photograph) is at 2.4. So as I see it, if the system should report on a tyre pressure issue it should have highlighted the odd one out at 2.4?
By the way, if I accept your logic, then it becomes nearly impossible to get the correct pressure into any car, given the pressure at 2.4 may mean 2.35 or 2.34, so how do you add air to any tyre and trust that the gauge is correct? Further, 'How do you know that the tyres are fine after driving for a short while' and accept it? - that way leads to acceptance of slow punctures and potential consequences sneaking up. It seems that if a system is incorporated into a vehicle and classed as a driver warning then it should work consistently and follow some logic. Otherwise don't have it.

There’s a lower limit and possibly some pressure monitoring going on for punctures.
Either way, the pressure in the tyres is not enough.
The car has warned you.
I believe the lower limit for the rears is 2.35bar.
The fronts might be 2.25bar

when inflating tyres, you can’t just do it blind: surely you have a pressure gauge?

So here’s the thing: fair enough you don’t know why the lower limit at the front is lower than the back tyres, but have you actually measured the pressure in each tyre? And if so, is it consistent with that reported by the app? Maybe your car does have a bug. But we can’t know until you measure with another gauge, preferably one that is more accurate than only one decimal digit.

 

[Rip Van]

are others experiencing issues with the tyre warning system?

Not with the tyre pressure warning system but easily remedied, issues with tyre pressures.?

 

[goose]

There’s a lower limit and possibly some pressure monitoring going on for punctures.
Either way, the pressure in the tyres is not enough.
The car has warned you.
I believe the lower limit for the rears is 2.35bar.
The fronts might be 2.25bar

when inflating tyres, you can’t just do it blind: surely you have a pressure gauge?

So here’s the thing: fair enough you don’t know why the lower limit at the front is lower than the back tyres, but have you actually measured the pressure in each tyre? And if so, is it consistent with that reported by the app? Maybe your car does have a bug. But we can’t know until you measure with another gauge, preferably one that is more accurate than only one decimal digit.

Yes I have a gauge and yes I use it when checking my tyres manually.

But thanks for your help. I will top up all of the tyres to 2.5bar and yes I have an inflater which can be set to the required pressure (given that it is in itself accurate). But to be extra sure I will use the gauge after inflating.

Hopefully that will sort it out!

I guess the point of this is to have faith in the old fashioned way of doing things and don't place too much faith in the automated car system.

Hey ho, onwards and upwards!

 

[Robf]

Yes I have a gauge and yes I use it when checking my tyres manually.

But thanks for your help. I will top up all of the tyres to 2.5bar and yes I have an inflater which can be set to the required pressure (given that it is in itself accurate). But to be extra sure I will use the gauge after inflating.

Hopefully that will sort it out!

I guess the point of this is to have faith in the old fashioned way of doing things and don't place too much faith in the automated car system.

Hey ho, onwards and upwards!

Low tyre pressure also will adversely affect the cars range, it’s beneficial to know in all vehicles but especially so in ev’s.

 

[mg4mc]

I had a look at the docs I have, and whilst there is a description of TPMS operation it is a bit light on detail (surprise). In summary of half a page of dense A4 (my highlights in bold text, my additions in italic)..

When thev ehicle is stationary, the sensor does not detect changes in acceleration, and the sensor enters the stationary mode. At this time, the sensor performs pressure sampling at intervals, and no signal is sent if the tyre pressure does not change.
As the vehicle speed increases, the sensor detects the changes in acceleration, and enters the rolling mode. At this time, the sensor sends a signal to the module at intervals.

The tyre pressure sensor continuously compares its last sampled pressure with the current sampled pressure. If it detects that the difference between them reaches a certain value in the stationary or rolling mode, it will recheck the pressure to confirm the situation.
When the sensor confirms that the tyre leaks quickly, it will ..... display the corresponding alarm message.
When the tyre pressure monitoring system detects that the tyre pressure (slowly) drops to the alarm limit, it will display the prompt messages such as Low Tyre Pressure or Check Tyre Pressure.

.... [If] The vehicle is driven at 40km/h (25 mph) or above, so that the sensor enters the rolling mode and sends a signal to make the instrument display the current tyre pressure....

[As a test]... When the vehicle is stationary, you can also reduce the tyre pressure (by more than 30 kPa [~4.4 psi]) to make the sensor in the stationary mode send a signal, and the instrument will also display the current tyre pressure.