Low pressure tyre warning

[DannySB1]

Well this is a bit of a coincidence! My first time back in a while and I come across this thread which funnily enough I've also been experiencing recently.

About 2 weeks ago the car says the right rear was low which I didn't think too much of as I have done a fair few miles recently so pumped it up. Went on holiday, came back and got the same warning ping again. Pumped it up again last night to a higher PSI and now it seems the car can't make it's mind up.

Got the low pressure warning ping when I got in the car this morning, but seemed to disappear once on the move. Could be nothing, or maybe I have a (very) slow puncture.

 

[fnegroni]

Well this is a bit of a coincidence! My first time back in a while and I come across this thread which funnily enough I've also been experiencing recently.

About 2 weeks ago the car says the right rear was low which I didn't think too much of as I have done a fair few miles recently so pumped it up. Went on holiday, came back and got the same warning ping again. Pumped it up again last night to a higher PSI and now it seems the car can't make it's mind up.

Got the low pressure warning ping when I got in the car this morning, but seemed to disappear once on the move. Could be nothing, or maybe I have a (very) slow puncture.

You must drive some distance for the sensors to send the new pressure readout.

 

[Buster72]

Despite me correctly inflating the tyres, I constantly get an amber warning saying that the Right Rear tyre pressure is low.

I have checked the tyre pressure with a tyre pressure gauge and it is towards the top of the recommended pressure.

It is only a minor annoyance.
So I was wondering if anyone else has such a problem?

 

[Torryhun]

Sounds like possibly a dodgy sensor

 

[Rolfe]

Merged. Have a read above.

 

[Buster72]

Merged. Have a read above.

Thank you.

 

[marno17]

How does the car know exactly, that pressure is low?

 

[andi]

I took this after 1hr run. Been having problem with rear sensors from new. (2022) MG4. Dealers said to monitor situation. You get fed up up of going dealers with same fault even with evidence, and they fob you off. Double tap picture for clear view

 

[ReintjeWA]

How does the car know exactly, that pressure is low?

It appears the MG4 actually reads pressure inside the tyre (as opposed to systems reading the rotational speed of the wheel). So there is like a little sensor on the inside of your valve that reads and transmits a pressure reading. It looks something like this:

 

[ReintjeWA]

I took this after 1hr run. Been having problem with rear sensors from new. (2022) MG4. Dealers said to monitor situation. You get fed up up of going dealers with same fault even with evidence, and they fob you off. Double tap picture for clear view

Have you tried resetting your sensors by letting out a lot of air (think down to 10 psi) and then re-inflating them to the correct pressures?

You might also want to see if a tyre shop can help, they might have machines to talk to your sensors, and they'll have more experience with it than your dealer.

 

[fnegroni]

I took this after 1hr run. Been having problem with rear sensors from new. (2022) MG4. Dealers said to monitor situation. You get fed up up of going dealers with same fault even with evidence, and they fob you off. Double tap picture for clear view

What do the sensors show when you first start the car in the morning and you’ve been driving for half a mile?

 

[gazza487]

I posted a thread long while ago as I had to do an ungodly amount of learning when I bought a Chrysler which had the system on when it wasn’t a common thing here. They do as many have mentioned have battery powered sensors in the rims which need to be of the correct type for the car and matched to the car (in the setup that mg use, some cars are smart enough to learn new sensors but that costs more or you lose functionality normally).

With them alerting like that, I would first inflate them to 0.1bar over the recommended on stone cold tyres and see how you get on. This because there is always some variability in the gauge you inflate with and / or the sensor itself. I can’t remember if the alert clears during a drive or if it needs a power down. Next note if it happens in specific places. I say that as these are radio transmitters just the same as the remote central locking. If you have done many miles the sensors do eventually die also (time and miles).

After that I’d either go to a dealer if it’s within warranty times or invest in autel tpms diagnostic kit. The correct model will scan existing sensors, clone their IDs on to new autel generic sensors (very good and well priced, universal to all cars assuming you have the tool), and write new sensors to the car as necessary.

Edit: recently bought a gun style tik tok usb rechargeable tyre inflator for about £7. Fab for topping off tyres, digital gauge with set point cut off with a light too. Well worth it now everywhere charges the earth for using the forecourt compressors.

 

[securespark]

Very interesting thread. We haven't had an issue with tyre pressures on our 23 phase 2 Trophy LR until recently.

But it's always the rear NS. Until today.

Mrs S has gone to a footy match with brother and father and I am (as ever) confined to bed with broken ankle. But I did my weekly status check. For the first time ever two tyre pressure warnings came up, but get this:

How can the system read exactly the same pressure for the rears as the fronts but flag them up as low? That I just don't compute, and obviously His Lordship (our name for the car!) doesn't, either.

As I said, the N/S/R normally pops up as low when it's cold, but it soon reads OK after a bit of driving. I guess today (in the NW where we are and the Midlands where the match is) it is very cold, so maybe the low pressure readings won't disappear with driving.

I've read what others say about ignoring the MG advice and putting 2.6 or 7 in each corner. Is that the solution here?

 

[GameZone]

Very interesting thread. We haven't had an issue with tyre pressures on our 23 phase 2 Trophy LR until recently.

But it's always the rear NS. Until today.

Mrs S has gone to a footy match with brother and father and I am (as ever) confined to bed with broken ankle. But I did my weekly status check. For the first time ever two tyre pressure warnings came up, but get this:

View attachment 33663

How can the system read exactly the same pressure for the rears as the fronts but flag them up as low? That I just don't compute, and obviously His Lordship (our name for the car!) doesn't, either.

As I said, the N/S/R normally pops up as low when it's cold, but it soon reads OK after a bit. I guess today (in the NW where we are and the Midlands where the match is) it is very cold, so maybe the low pressure readings won't disappear with driving.

I've read what others say about ignoring the MG advice and putting 2.6 or 7 in each corner. Is that the solution here?

I don't know, but it's more likely to get this warning while it's cold. I just feel them up to 2.7 or 2.8, and it'll go away.

 

[andi]

Hi
N/S/R usually reads low but this came up a few months ago, dealers just said monitor.
Going to change tyres and TPMS on rears at same time with none gen. Fed up of complaining. From new.

 

[securespark]

Being a passenger (my licence was withdrawn for eyesight issues in 2013 ), I'm not too familiar with the colours on that display.

Is it saying that the front wheels at 2.4 bar are fine, but the rears that are higher are too low???

 

[Roberto 2761]

Trust me mine does the same normally this happens with the sensors when below 3 degrees, but the tyres are the right pressure I have got used to it annoyingly.

 

[gazza487]

Very interesting thread. We haven't had an issue with tyre pressures on our 23 phase 2 Trophy LR until recently.

But it's always the rear NS. Until today.

Mrs S has gone to a footy match with brother and father and I am (as ever) confined to bed with broken ankle. But I did my weekly status check. For the first time ever two tyre pressure warnings came up, but get this:

View attachment 33663

How can the system read exactly the same pressure for the rears as the fronts but flag them up as low? That I just don't compute, and obviously His Lordship (our name for the car!) doesn't, either.

As I said, the N/S/R normally pops up as low when it's cold, but it soon reads OK after a bit of driving. I guess today (in the NW where we are and the Midlands where the match is) it is very cold, so maybe the low pressure readings won't disappear with driving.

I've read what others say about ignoring the MG advice and putting 2.6 or 7 in each corner. Is that the solution here?

I guess there are rounding errors. They may be set at say 30psi which would work out as some ungodly long decimal which rounds up in other formats.

 

[AndyL61]

I believe the cut off point for the alarm is slightly higher for the rears as they always seem to go off first . But also as they are to only one decimal place (in BAR) you could have the rears at say 2.38 rounded to 2.4 and fronts at say 2.42 also rounded to 2.4. Either way they need a bit of air due to the lower temperatures.

 

[WonkoTheSaneUK]

FWIW - I keep my tyre inflator set to 37psi (2.55 bar).