tyre pressure alert

[Trebor77]

Twice within the last 8000 miles I have had the tyre pressure alert sound.  On both occasions all was OK.  Is this unusual ?   KK

[SWBoy]

5 minutes ago, Trebor77 said:

Twice within the last 8000 miles I have had the tyre pressure alert sound.  On both occasions all was OK.  Is this unusual ?   KK

Have you reset the TPMS on the infotainment screen after checking/adjusting the tyres pressures?

[Trebor77]

yes on both occasions, and the tyre pressures were ok

[SC03OTT]

Not sure I’d say two alerts over that distance is unusual. Might be worth checking all pressures, topping up a bit then resetting. It’s not a fool proof system and can throw up a false positive. Still great for what it is though. 

[Trebor77]

Hi & yes I agree, but if it throws up so many false positives, I might ignore it when I ought stop & check. I guess  ignorance is bliss

[SWBoy]

55 minutes ago, Trebor77 said:

yes on both occasions, and the tyre pressures were ok

Are all the tyres the same manufacturers/model?

 

It's not unusual for tyres nominally the same size (width/profile/diameter) to actually be slightly different in size which can be enough to trigger the ABS based TPMS systems.

[Ootohere]

^^^ If there is a slight difference as when you put the spare on which is an odd one out, you reset the TPMS and then it is not flagged as being a different size.

If you put the repaired tyre / wheel on and the spare comes off, but you do not reset the TPMS then it might flag a 'loss of size / puncture'. 

That is the point about setting the TPMS, it picks up what you set, you can have 4 different pressures on 4 wheels and the system is happy as Larry.

[CCTaylor]

I have had one false positive alert from the TPMS in 18,000 miles. I also had it correctly report a puncture. After the false alarm I have invested in a little stick pressure gauge which I keep in the glove box. This will allow me stop at the next lay-by and confirm if it is puncture or not.

 

Edit

 

Just seen the post above totally agree with it.

Edited 25 October, 2017 by CCTaylor

[Trebor77]

3 minutes ago, Headinawayoffski said:

^^^ If there is a slight difference as when you put the spare on which is an odd one out, you reset the TPMS and then it is not flagged as being a different size.

If you put the repaired tyre / wheel on and the spare comes off, but you do not reset the TPMS then it might flag a 'loss of size / puncture'. 

That is the point about setting the TPMS, it picks up what you set, you can have 4 different pressures on 4 wheels and the system is happy as Larry.

But would it not do so immediately  ?, rather than several weeks / months later ?

[Ootohere]

No idea what is wrong with yours, i was just commenting on what SWboy posted.

 

The TPMS just knows if the circumference has changed from that set.

Use an accurate tyre pressure gauge.

All 4 tyres can go down evenly and the system might never give an alert.   The system was only ever designed for Run Flat tyres to let the stupid know they had a puncture.

[Nickj633]

Hi, you probably already know this, but remember that to set the TPMS, you must do it with the ignition on, but the engine off, set the values, then turn the ignition off. Until I read this I had several false alarms.

[Gerrycan]

The TPMS system is capable of informing about possible issues with an individual tyre and identifying it.

The system can also warn of what it thinks are general low pressures on all tyres relative to the initial setting.

The general warning can theoretically be initiated by several situations:

• general air loss over time (my own tyres are near end of life, quite porous and need regular topping);
• temperature affects pressure, which is why it is always recommended to set pressures when tyres are cold 
• manual interference from unlawful, or perhaps poor equipment/procedures during servicing

You don't say what warning was thrown up on the two occasions and what action you took with your 'check' (whether a quick eyeball to see if they were round or more correctly with pressure gauge).

What is your usual tyre checking procedure and schedule? Theoretically there would have been checks/adjustments several times in 8000 miles and the TPMS reset each time.

Tyres should be set when cold,  a few psi higher than manufacturers general recommendations or at their 'eco' recommendation and also with reference to their vehicle load/weight guides. 

 

The wrong thing to do is to go for fast run up the motorway, pull into a service station and then adjust/deflate all tyres to the recommended pressures while they are still hot and then zoom off.

 

I've found the TPMS system on my vehicle issuing remarkably accurate warnings for all the individual tyre issues and a general warning for when I left too long a period between checks.

 

The recommendation from above to get you own quality  pressure gauge is a good one as there is no guarantee the forecourt gauge is accurate.

 

[Ootohere]

^^^ Pretty damn accurate these days when you pay 20 pence, 50 pence even £1 with Air & Windscreen Wash Fluid. 

They are calibrated obviously. Multi Nationals can not take peoples cash / money and provide some dodgy service......

 

Easy when you have a Tyre Pressure gauge to check that against the pressure you just put in with the usually digital set Filling Station Compressor.

Then the Tyre pressure gauge is with you if you ever get a 'TPMS' warning, to see if all 4 are as they were when last checked.

 

All rather simple really, it just needs doing.

[Gerrycan]

1 hour ago, Headinawayoffski said:

^^^ Pretty damn accurate these days when you pay 20 pence, 50 pence even £1 with Air & Windscreen Wash Fluid. 

They are calibrated obviously. Multi Nationals can not take peoples cash / money and provide some dodgy service......

 

Easy when you have a Tyre Pressure gauge to check that against the pressure you just put in with the usually digital set Filling Station Compressor.

Then the Tyre pressure gauge is with you if you ever get a 'TPMS' warning, to see if all 4 are as they were when last checked.

 

All rather simple really, it just needs doing.

I forgot about the UK pay-for-use versions I saw there last month, bit of a surprise but I was not sure how widespread it was.

Currently Australian facilities are still free but I do carry a cheap footpump in the car and a gauge.

 

[alladin1616]

I managed to get 2 types of warning,:

1. when one of the rear tyre had a proper puncture (and I had to replace the tyre)  it warned specifically which tyre had the problem something in the lines of "no air pressure on rear left tyre" or something similar. 

2. when the air pressure was not same on all tyres, a generic warning "check air pressure" or something on those lines without being specific about the tyre. 

[nidza]

You wouldn't believe what I've just read yesterday, just before crossing on this topic Today. This may explain false alarm on indirect TPMS system in recent VAG. It was really difficult to find correct info on internet, so little good articles which really explain how this system works!

 

The system is far more sophisticated then I have initially thouhgt. Yesterday I had warning that all 4 tires have lost the pressure. Stopped by and measured minus 0.2bar, exactly the same, in all fours. This raised a question, how possibly the system can detect this if circumference of all 4 wheels is exactly the same?

 

ABS sensor reads wheel speads, independently. System processes this info for various other subsystems, but it is very important for TPMS as well. It also reads small variations of speeds caused by torsion resonation of wheel because of rubber! Yes, rubber is elastic, and vibrates differently according the amount  of air which is inside. Stiffnes changes. So, after you calibrate the system, it starts reading pattern and it takes some kilometers to learn and filter misinformation. If any of the wheels changes the level of stiffness, vibrates differently and system reads pattern change, and warns you. This way, it can read each wheel independently, doesnt really need to compare speeds between wheels, although it is doing this as well.

 

Anyway, I was impressed of this clever engineering. 

 

False warning may occur if wheel vibrates on a particular way it misinterpets as air loss. It doesn't occur often, as I can read by your experiance, but it always occurs when you really have a puncture. So, trust your system, even if the warning is false. Could be effect of a bumpy road, or significant temperature change (probably triggered my alarm, 20+ degress less plus water on road in just a few days).

 

I hope this info I got ran into you find useful. 

 

Edited 26 October, 2017 by nidza

[mbames]

Mine went off one morning after a spirited drive down a dual carriageway.  I pulled over and checked and there was maybe 1psi different between the fronts, but I wondered if the speed (around 70ish) and the slight difference was enough to trigger the warning where was 60 and less it was fine.

I adjusted pressures later in the day (cool tyres) and haven't seen the warning since.

[Redboy]

You may have a nail or similar if the alloys are not old or damaged. I have always found Skoda TPMS alerts accurately. On my MkII after 7 years, the system alerted me to a loss of pressure caused by an alloy leaking from the inner bead. On my MkIII I it alerted twice over a few days, I replaced 3-4 lb of air and checked the tyres for damage both times. A day or two later the third alert made me take it to my local tyre fitter, where they found a screw and a nail, both with their heads broken off and buried into the centre tread on exact opposite sides of the tyre. 

[TDIum]

Recently I've had the false warning twice on the same wheel. I check the pressure and it's very close to where I set it before, but yes the tyre is near the end of its life. 

Being also a biker and mountain biker I check tyres often using an accurate gauge. 

[Trebor77]

On 10/25/2017 at 22:33, Nickj633 said:

Hi, you probably already know this, but remember that to set the TPMS, you must do it with the ignition on, but the engine off, set the values, then turn the ignition off. Until I read this I had several false alarms.

This is interesting, I will check

[Trebor77]

On 10/26/2017 at 09:18, alladin1616 said:

I managed to get 2 types of warning,:

1. when one of the rear tyre had a proper puncture (and I had to replace the tyre)  it warned specifically which tyre had the problem something in the lines of "no air pressure on rear left tyre" or something similar. 

2. when the air pressure was not same on all tyres, a generic warning "check air pressure" or something on those lines without being specific about the tyre. 

This what I got yes, On both occasions I stapped ASAP, visual check, proceeded carefully, then checked pressures later when cold. All was well

[Ootohere]

^^ When you say 'All was well',  does that mean when you checked the 4 tyres the pressures were the very same as when last checked and the TPMS set?

[ClarkWGriswold]

On ‎28‎/‎10‎/‎2017 at 16:28, Trebor77 said:

This is interesting, I will check

I'm going to do this as well as I'm getting quite a few false alarms.

 

Rich

[Nickj633]

On 25/10/2017 at 22:33, Nickj633 said:

Hi, you probably already know this, but remember that to set the TPMS, you must do it with the ignition on, but the engine off, set the values, then turn the ignition off. Until I read this I had several false alarms.

 

Just to reinforce my point.

 

I had a severe blow out in Scotland in September, and due to the crap repair kit had to call out RAC. ignoring the boring parts, when the new tyre was fitted i followed what i thought was the correct procedure for resetting the TPMS, but a few days later i kept having the warning 'bong' but with no detectable problem with the tyre. once i took the time to read the manual, i saw that after you change a tyre, to correctly re set the system it MUST be done with the engine off. So turn on the ignition, boot up the infotainment, go to the TMPS, press the relevant buttons to re-set, the turn the ignition off straight away. This will store the new figures, you can then start the car as normal. After doing this i had, and still have had, no false alarms.

 

Nick

[ClarkWGriswold]

Cheers Nick. I followed that procedure yesterday. Hopefully that will stop the false warnings now.