Continuing to familiarise myself with the owners manual. I noted the tyre pressure monitor button is shown on the centre console and slightly disappointed I do not have this button and therefor I am without this feature. Yesterday, having had the car for two weeks I decided to check the tyre pressures for the first time and found one tyre 1.5bar lower than the other three. So I got the pump out, set the fourth tyre so all at the correct level and then went on my journey. On my return part way down the motorway I got a beep and a message on the maxi dot display saying there was a 'loss of pressure, check and record all tyre pressures'. A tyre symbol was now lit on the display. Bl...y h..l I thought and reduced speed, pulled into a service station and did a rudimentary tyre check; no problem identified so continued gingerly on my journey home.

Decided to check all pressures when tyres had cooled but then reality hit me. If I haven't got the monitor system how come I get a warning? Having previously dismissed reading up on the tyre pressure monitoring because I hadn't got it, I now read it and the penny dropped (button not needed as now via Colombus touch screen). Tyres presumably inflated and set in the infotainment system by the dealer before I collected the car (possibly with the one at the lower level). Having inflated to the higher level before my journey today, and not reset the tyre levels in the infotainment system (because I hadn't read up about it), my first suspicion now is that it has recognised a difference from the original rotational speed of the wheels. Will check all pressures tomorrow and reset the system and expect the tyre symbol to be extinguished.

We live and learn, and I wonder what other features I may find I have or do not have! Am I the only one fooled by what the owners manual says or doesn't say?

You have the set button on your screen ( amundssen or columbus)

 

A button on the right side of the touchscreen that says CAR, and in that menu you will find set tire pressure.

 

The old Octavias had the button on the centre console.

 

Ahhh.. sorry, i didnt read all.

 

You already got it figured out.  :-)

Edited 5 October, 20169 yr by surjamte

Are you reading the printed manual provided with the car because these are usually quite out-of-date & missing some features.

 

Its better to use the online version (via the via or Skoda Service app) which is constantly updated with & seems much better.

 my first suspicion now is that it has recognised a difference from the original rotational speed of the wheels.

 

This is exactly how the system on the O3 works.

It monitors wheel rotation & looks for a change compared with the original setting & other tyres.

 

Its important to reset the system each time you reinflate/check or change your tyres e.g. winters/summers.

Its important to reset the system each time you reinflate/check or change your tyres e.g. winters/summers.

 

I'd be interested to know whether there's a measured pressure difference required to set it off, or if it's pot luck on what type of wheel / tyre and also conditions, i.e. temperature etc. I know from experience that swapping from my 17" with summers to 16" with winters always sets it off if I don't recalibrate, but when I have had an underinflated tyre it hasn't gone off, so presumably hasn't seen enough of a difference before I noticed anyway!

I'd be interested to know whether there's a measured pressure difference required to set it off

There are no pressure measuring sensors in the wheels, it's done by software in the ABS comparing the rotational speed of the wheels against things such as the other wheels, long term averages, etc.

 

Since the amount that the rolling circumference will change depends on the characteristics of the type of tyre fitted (e.g. sidewall stiffness) there is no predetermined pressure difference that sets off the TPMS warning.

 

When TPMS was made compulsory on new vehicles all manufacturers looked for cheaper ways to implement a system rather than the expensive sensors in wheels with a radio link to receiver(s) on the body - and wheel rotational speed comparison is what the vast majority of cars use.

Edited 6 October, 20169 yr by PetrolDave

@Gabbo. Thanks for the tip and info. Been using a downloaded version on my tablet, Anglicky 05.2016, for both Owners Manual and the Columbus Manual but now have the Skoda Service app. on my phone so will have a look at that (if my eyes can stand the smaller print ). Both much more convenient than turning pages in the paper version and trying to hold the book open.

Thanks to all for responses and helpful info.

Checked tyres today, cold, and find three tyres same pressure but the one I had previously found low and re-inflated is now reading high! So, I have deflated it to the same as the others and for the first time set it in the Car menu on Columbus (along with doing the other initial set-ups). That has at least removed the tyre pressure warning symbol but I am still confused, so to be safe and sure I will check all again in a day or so and reset in the car menu as necessary.

The tyre I checked and found high this morning is the one that catches the sun first, its partner on that side is still in shadow for some time, as are the two on the other side. Can the morning sun at this time of year in the UK make such a difference of 0.2bar or am I being too fussy in getting values perfect (one of my in-built traits)?

Edited 6 October, 20169 yr by AccoSnr

Can the morning sun at this time of year in the UK make such a difference of 0.2bar or am I being too fussy in getting values perfect (one of my in-built traits)?

 

I believe that I have seen a similar effect. A combination of my (admittedly not very recent) physics learning and Microsoft Excel leads me to believe that at this time of year with typical tyre pressures, a change of 0.2 bar as a function of temperature would equate to around 17°C rise from ambient. Seems a bit much, but then again I have seen a similar thing like I say (although I wouldn't swear to the time of year that I'd seen it).

I believe that I have seen a similar effect. A combination of my (admittedly not very recent) physics learning and Microsoft Excel leads me to believe that at this time of year with typical tyre pressures, a change of 0.2 bar as a function of temperature would equate to around 17°C rise from ambient. Seems a bit much, but then again I have seen a similar thing like I say (although I wouldn't swear to the time of year that I'd seen it).

Well, I don't actually have tyre thermometer, but I have noticed the "sunny side tyres" on my car feeling warm to the touch wrt the "shady side".

Considering that this would be a normal part of tyre use - indeed on a good run they'll get quite a bit more heating than this - then it's certainly nothing to worry about. If you want to make sure they're matched though it might be an idea to check the tyres first thing in the morning on a cloudy day though, then you can be certain that they're all 'cold'.

Well, I don't actually have tyre thermometer, but I have noticed the "sunny side tyres" on my car feeling warm to the touch wrt the "shady side".

On my other car (a Citroen C1), which doesn't have any form of OE TPMS, I've fitted this http://www.tyrepal.co.uk/products/tpms-for-cars-specification

 

This shows pressure and temperature of each tyre, so I can see the effect of sun and driving on temperature and pressure.

 

On what used to be my typical 6 mile commute the tyre pressures would rise by as much as 3 PSI when correctly inflated, but as much as 5 PSI when slightly under-inflated.

 

The difference in temperature between the sunny side and shady side when parked could be as much as 8 Celsius.

 

This is with 195/40 x 16 tyres.

Having statistics from a car w/ TPMS w/ sensors inside the tyres - cold tyre when heated in normal weather shows difference of ~ 0.3 atm == ~ 0.3 bar

 

Yes also the sun heating on side gives you delta, no escape.

 

Check them when they are cold, before departures.

 

BTW I was told the ABS TPMS can catch difference of 0.2-0.3 between tyres.

BUT also read if you start w/ flat tyre it might miss it? (not logical but need to ask here).

 

Also perfection is not easy here - what do you use to measure the pressure? I bought Michelin pump hoping it will be average at least...

Based on my old mkII octavia, the tpms will activate after a pressure loss of about 0.5 bar.

I believe that I have seen a similar effect. A combination of my (admittedly not very recent) physics learning and Microsoft Excel leads me to believe that at this time of year with typical tyre pressures, a change of 0.2 bar as a function of temperature would equate to around 17°C rise from ambient. Seems a bit much, but then again I have seen a similar thing like I say (although I wouldn't swear to the time of year that I'd seen it).

Agree 17 seems a large rise especially today would think 10 to 12 with the wind, however, probably other factors which affect any change. Will try and rise out of bed before the sun appears round the corner as thats a sensible suggestion echoed by others.

Check them when they are cold, before departures.

Also perfection is not easy here - what do you use to measure the pressure? I bought Michelin pump hoping it will be average at least...

Will do, and I used my 40yr old pencil guage which I have a preference for rather than the dial type although recently sent for a digital for comparison.

From comments it seems like the TPMS will react to quite small changes, although there can be other causes of wheel rotational speed difference which may also activate it and not just pressure change.

Have now looked at the Skoda Service app and my first impressions are very positive so suggest others who are unaware might like to check it out.

Hope this post with "quotes" translates OK - something else I am learning about. Yeh, it worked.

Edited 6 October, 20169 yr by AccoSnr

This is the first car I (actually my wife) have had with TPMS.  It works!  We recently did a trip to Ireland.  I checked the pressures before we left (digital gauge) and they were 31/31/31/29 (ought to be 32).  (I think better in psi.)  I thought that was close enough for a short journey in cool weather, as we were in a hurry, etc etc.  Yes, I know I should have get them right before setting off.  About 50 miles into the journey the TPMS gave a warning.  Out came the handbook, and I gave the tyres a visual check - all OK.  So we carried on a little more slowly.  After an overnight stop, I found a garage with an airline and put them all up to 32 (funnily enough, the gauge in the petrol station gave exactly the same pressures as I had found the night before).  Of course, it took another read of the book to realise that I now had to reset the system with the new pressures.  After that, no further problems.  As the wrong pressures were obviously there from the start, I reckon the system must have waited for at least 50 miles before warning us, as it was clearly not a loss of pressure on the journey that caused it to give the alarm.  But I am happy with the system - although I won't stop checking them every week or fortnight as I always have done.

The system goes through a learning period when reset and stores values for each wheel at different speed ranges. Presumably so it can detect if more than tyre is low. The smaller the drop in pressure the more difficult it is for the system to spot. Steady speed in a straight line are the best conditions for problems to be picked. So if you drove the for 50 miles on twisty roads at variable speed, then got on a motorway or dual carriageway it is not surprising that it was at that point a slight drop triggered the system.

Putting how the TPM works aside, how could you not visually see that the tyre was under inflated. It would of only had about 12/13 psi in it and look flat.

Putting how the TPM works aside, how could you not visually see that the tyre was under inflated. It would of only had about 12/13 psi in it and look flat.

 

Depends on the tyre.  Potentially not on a low profile tyre on an 18" rim.

From comments it seems like the TPMS will react to quite small changes, although there can be other causes of wheel rotational speed difference which may also activate it and not just pressure change.

Have now looked at the Skoda Service app and my first impressions are very positive so suggest others who are unaware might like to check it out.

Hope this post with "quotes" translates OK - something else I am learning about. Yeh, it worked.

yeap, in the service manual it's described that it can alert if the weight is not even across the chasis,change of a tyre,change tyre possition(?),winter chains put in general anything that can shift the rotation data.

My old habits are something my father and friends laugh but I check the pressure before longer trips, plus (trying) once a month...

Putting how the TPM works aside, how could you not visually see that the tyre was under inflated. It would of only had about 12/13 psi in it and look flat.

Meta55b

Your quite right so I checked my post and figures and see the decimal point has jumped; should have been 0.15bar, not 1.5 - sorry folks. Specsavers?

Meta55b

Your quite right so I checked my post and figures and see the decimal point has jumped; should have been 0.15bar, not 1.5 - sorry folks. Specsavers?

I did wonder that you meant .15, going by some stories people have posted about dealers and what they have done you never know lol.

I use a small electronic gauge to check them. The packaging claimed +/-1 PSI accuracy when I bought it, but this would undoubtedly by at room ambient temperature in the factory. What it is at -5°C or 35°C and after some time spent living in my car is totally unspecified!

 

It seems to agree with the analogue gauge on my footpump when I do have to add some air, so I trust it, but I also accept that if it's within a couple of PSI in absolute terms then it's close enough, and as close as I'll get shopping in Halfords!

Having statistics from a car w/ TPMS w/ sensors inside the tyres - cold tyre when heated in normal weather shows difference of ~ 0.3 atm == ~ 0.3 bar

 

 

Also perfection is not easy here - what do you use to measure the pressure? I bought Michelin pump hoping it will be average at least...

 

 

 

It seems to agree with the analogue gauge on my footpump when I do have to add some air, so I trust it, but I also accept that if it's within a couple of PSI in absolute terms then it's close enough, and as close as I'll get shopping in Halfords!

I use a BSI kite-marked pencil gauge; you can buy them in Halfords for about a fiver. And being BSI marked it must "be right" or else Halfords get trouble.

any links for these gadgets/guages?

Nitrogen

Nuff said ?