Tyre pressure monitor

[ali831]

Warning tonight 5 miles into my 17 mile commute home.
Boring slow 5 miles at that, between queuing traffic and 50mph average speed cameras on the M74/M73.

Decided to carry on home at 60mph max, and checked the pressures there.

Had been set at 35psi all round ( on 18's ), and measurements came in at

36psi on both fronts, 35psi on back right, 34.5psi on back left.

Who knows why the warning came on . . .

when ours did that we reset it and a few days later it came on again. Turned out there was a headless nail imbedded right in the tread so could not be seen when doing an external check.

 

[oldbutnotwise]

when ours did that we reset it and a few days later it came on again. Turned out there was a headless nail imbedded right in the tread so could not be seen when doing an external check.

Did your sensor go off with 0.5psi reduction from when it was set ( like mine ) ?

 

[ali831]

no I think is was nearer 2 psi, put more air in, reset then slow puncture took a few days to set it off again

 

[mykro]

I have indirect pressure measurement viac wheel rotation (ABS sensor) and it doesnt work properly. Twice I had deffet on pneumatics and it doesnt complain - no warning ... After 500m with no air was warning. So what is wrong with that ?

 

[Mr Pig]

I have indirect pressure measurement viac wheel rotation (ABS sensor) and it doesnt work properly. Twice I had deffet on pneumatics and it doesnt complain - no warning ... After 500m with no air was warning. So what is wrong with that ?

Do you set the pressure and calibrate it?

 

[mykro]

yes after use compressor with air, In infotainment unit I set tire pressure.... but I think that there is a big delay after which system evaluates that pressure is lost ... good to know how to adapt limit or difference between wheels

 

[RUM4MO]

Warning tonight 5 miles into my 17 mile commute home.
Boring slow 5 miles at that, between queuing traffic and 50mph average speed cameras on the M74/M73.

Decided to carry on home at 60mph max, and checked the pressures there.

Had been set at 35psi all round ( on 18's ), and measurements came in at

36psi on both fronts, 35psi on back right, 34.5psi on back left.

Who knows why the warning came on . . .

Yes, very annoying the first time it sounds and you find no good reason, I was on a motorway, so took the first exit and as usual took a few miles to find a spot to stop at without causing any road blocking, only to find no proper reason and then getting turned and back onto the motorway - but that was better than finding that I had a leaking tyre and wrecking it before noticing anything! Not a perfect system, but maybe useful - enough.

 

[Mr Pig]

yes after use compressor with air, In infotainment unit I set tire pressure.... but I think that there is a big delay after which system evaluates that pressure is lost ... good to know how to adapt limit or difference between wheels

I don't think the gauge on the compressor is accurate enough. I use a dedicated tyre gauge after blowing up the tyres.

Yes, it needs to 'learn' the rotation speeds of the wheels after the tyre pressures have been set. How long it records rotations speeds for after the reset button has been pressed I don't know but this process is open to error I think. Say it monitors the rotation for five minutes and it just so happens you drive on mostly left hand bends. Would that muck it up? I don't know but I think it's a possibility.

Because it only monitors relative rotation across an axle it also means it can get caught out if both tyres on an axle loose pressure. Sounds unlikely but it has happened to me. Both front tyres lost a similar amount of air over time and the bing-bong didn't pick it up.

I've also had false pings a few times. Very rare though . Bottom line is that it's a fairly basic and limited system but it's better than nothing.