I was coming home from work yesterday after a very long day when the XC60 decided to present me with this message.
'Tyre pressure low, check pressure and re-calibrate'
I had about 12 miles to go to get home so I did what all drivers do....I listened to the seat of my pants and kept going.
It was handling fine and the annoying thing was that the diagram on the dashboard showed on orange spot on all four tyres?
Surely if it's that b***** clever it can tell me which tyre has a problem?
I decided that as Ian loves technology it could become his problem when he got home.
He sighed (it was 6pm and we'd got up at 12.30am for work) and asked what I did?
Nothing? Just drove it home.
'Did you switch the ignition on again after you parked it up to see if it cleared the message?'
No, why would I? It's not a b***** computer, is it?
So, off he goes, clutching a set of keys and sighing deeply.
10 Minutes later....he's back.
Have you sorted it?
Yes, I resorted to the tyre pressure gauge and one tyre had 2lbs les than the others so I pumped it up.
Has that cleared the message?
Yes, but if you had switched it on again it would had cleared anyway????
I'm still confused about what I did wrong and hope some of you techie blokes can tell me.
I did what all good drivers do....drove by the seat of my pants and got the car home, so what's wrong with that?
...and more to the point, why is the XC60 telling lies and getting me in trouble?
Pat
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Even a tyre pressure monitor system using only the ABS should have been able to tell you which tyre it thought was under-inflated. I assume yours uses ABS and does not have pressure monitors which measure actual pressures.
VAG systems (that don't have the valves that monitor pressures) are set with a button when the pressures are checked and known to be correct. If pressure then drops from the set 'value' which is based on the rotation of the wheels the next time you drive then you will be told.
I would hope that turning the ignition off and back on does not reset it. If you had a slow puncture on a journey you'd want to detected the next time you started.
Were all 4 tyres slightly deflated and the colder temperature triggered this based on lower pressures? But would it drop by that much?? I know the pressures in the Passat which did have proper TPMS via valves dropped more than you'd think in colder weather.
If this was now my car, to gain some confidence in the system (when it's dry out) I'd deflate a tyre slightly and see what it says when I drive it. All four wheels down or just the one I took air out of.
About 12 months ago my Audi A3 flagged loss of pressure in one wheel when on the motorway and I had a few miles before I came off for my junction. Even if it was deflating I decided to (a) slow down and drive in the near side lane and (b) keep going. Came off at the junction and it felt fine so I just kept going and checked when I got home. False alarm. But better that than no warning.
Last edited by: rtj70 on Tue 18 Oct 16 at 17:28
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Pat - I must have missed something because I thought you still had a V70.
Anyway, my understanding is that the system works by using the ABS sensors to measure the rotation, so if there is any difference then the system flags it.
Nothing you did wrong, if it happens again pull into a petrol station and check the pressures.
I guess if one has dropped 2 psi then you should check it again in a day or two in case you have a slow puncture
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>> Nothing you did wrong, if it happens again pull into a petrol station and check the pressures.
But if there was a drop in pressure, what did your other half find? Because something must have caused it. Simple pumping it up is the start of investigation I would have thought. I could drop again.
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>> Even a tyre pressure monitor system using only the ABS should have been able to
>> tell you which tyre it thought was under-inflated.
Does yours? The Roomster one doesn't. It does work though, came on when one tyre was 2psi down like Pat's.
No TPM on the Outlander so I have to kick them.
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>> Does yours? The Roomster one doesn't. It does work though, came on when one tyre
>> was 2psi down like Pat's.
Not fitted on my Roomie. One one hand I'd regard an alarm at 2 psi as de-minimis or crying wolf. OTOH if deficiency was 2psi but going rapidly towards 4, 6 then 8 I'd be grateful for early heads up.
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>> Not fitted on my Roomie. One one hand I'd regard an alarm at 2 psi
>> as de-minimis or crying wolf.
Remember, it's not measuring a difference in pressure to the other tyres. It's measuring a relative difference, since it was last reset, in the rotation rate of each tyre to the others. So it's not telling you that there is a pressure difference, it's telling you there has probably been a loss of pressure.
It does take a long time to react, i.e. miles for such a small differences, but when it does it seems to be right. I assume it takes a fair distance to calibrate as well after a reset.
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>> I assume it takes a fair distance to calibrate as well after a reset.
>>
My TPMS takes 30 minutes driving to calibrate itself after a reset.
Last edited by: Old Navy on Tue 18 Oct 16 at 20:19
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>> it takes a fair distance to calibrate as well after a reset.
And for that reason I'd go for a true TPMS.
Some things I will spec if I can for a new car that I see as a safety thing and include TPMS and at least Xenon headlights. I look forward to testing the matrix LEDs. Latest 5 series apparently can illuminate up to 500m ahead.
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>> Some things I will spec if I can for a new car that I see
>> as a safety thing and include TPMS and at least Xenon headlights. I look forward
>> to testing the matrix LEDs. Latest 5 series apparently can illuminate up to 500m ahead.
>>
I take it you do not fund your cars.
As an impoverished pensioner I have to think about maintenance costs.
Last edited by: Old Navy on Tue 18 Oct 16 at 21:14
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>> I take it you do not fund your cars.
I have a car allowance and can pay up a bit above that (out of salary). I could opt to just take money. It's a benefit car. So think of it just like salary if you want. If I take car I pay tax on it - hence seeking to go for a lower BIK charge. The A3 1.4TFSI DSG car is pretty good.
>> As an impoverished pensioner I have to think about maintenance costs.
But you have a good pension from serving in the armed forces. Many younger people will not have a final salary pension let alone a generous one. My final salary pension closed many years ago and retirement age went up too.
Don't forget your pension is partly paid by me and other on here ;-)
Last edited by: rtj70 on Tue 18 Oct 16 at 21:34
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>> Don't forget your pension is partly paid by me and other on here ;-)
>>
After 35 years of watching your backs I have earned every penny of my pension.
Last edited by: Old Navy on Tue 18 Oct 16 at 21:45
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> After 35 years of watching your backs I have earned every penny of my pension.
>>
An impoverished *and* modest pensioner ;)
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>> An impoverished *and* modest pensioner ;)
>>
Me, modest, never! :-)
Last edited by: Old Navy on Tue 18 Oct 16 at 21:59
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And thank you. Not something I'd like to do - being in confined spaces with recycled air.
It was a more general comment - lots of others in easier jobs are on pensions paid by us. Even Pat's old age pension is being paid for by current working adults including herself and Ian.
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>> And thank you. Not something I'd like to do - being in confined spaces with
>> recycled air.
>>
The recycled air was cleaner than the air in any city or traffic jam. Well monitored and kept to a tight spec, also way cleaner than the air in an aircraft.
Last edited by: Old Navy on Tue 18 Oct 16 at 22:06
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Well
>> monitored and kept to a tight spec, also way cleaner than the air in an
>> aircraft.
>>
I wouldn't say all though, some have higher standards, for air to breathe,
than that given to medical patients. Some are capable of filtering out every type of nasty. A very small number mind. But don't worry though, I don't think it's the types impoverished pensioners would be flying on ;)
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>> Not something I'd like to do - being in confined spaces with
>> recycled air.
>>
No, that's one reason I prefer an older car.
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>> Don't forget your pension is partly paid by me and other on here ;-)
No it's not, it's completely paid for by you and others on here, just like I paid the pensions of those retired when I was working.
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>> Does yours?
Got me wondering. It might not have been specific. I liked the peace of mind of the proper TPMS on the Passat. I spec'd it over and above the simple kind when I knew it came with self sealing tyres (not run flats).
It probably cost me just over £1 per month so £36 over the three years. I'd choose it again.
Last edited by: rtj70 on Tue 18 Oct 16 at 20:00
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>> I liked the peace of mind of the proper TPMS on the Passat.
>>
Does that turn it into an active system with pressure sensors on each wheel?
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There was indeed a pressure monitor per wheel in the valve. List price was about £130. For a £29k car that's nothing.
On something like a Phaeton it could even monitor the pressure of the spare wheel in the boot. Something a mere Passat could not do. It needed an extra sensor I guess - so about another £1.00.
Last edited by: rtj70 on Tue 18 Oct 16 at 21:06
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I had this on the Beemer the other week - took some fiddling to get all four tyre back some sort of balance. It's a remarkable system though with the computer providing real time readings on a large Pictogram. The Tiger's front tyre gave an alarm n the way to work the other morning - dropped under 34psi from the normal 36psi. A giant red light and a digital reading made me turn back. There were no visual problems with the tyre - topped up it's kept its pressure ok. I think the tech is brilliant a safety critical system with proper alarms.
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I don't think a full TPMS is a great advantage over an ABS based wheel rotation monitor system, they both warn you of a slow deflating tyre, and nothing is going to predict a sudden blowout deflation. Wheel sensors are an unnecessary complication.
Last edited by: Old Navy on Tue 18 Oct 16 at 22:37
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Well, at least I understand how it works now!
I'd really prefer if the car didn't talk to me when I'm enjoying driving it unless there is something really wrong!
I still miss the V70 Mikey, and more to the point the 'extra pot' it had:)
Pat
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TPMS on my CRV - read about it & lots of other electronic wizardry when I bought the car & waded through the 500 page handbook.
TPMS never crossed my mind until I had the tyres rotated - ran about 5 miles & it pronounced a low pressure / puncture. Book not at hand nipped back to the tyre place & they said it was 99.9% chance it was the TPMS that had not been reset.
TPMS like most of the electronics in the car have been forgotten by me as useless - in theory I can switch on AC/Heating, dial numbers & loads of othe matters.....complete failure for me - wasted the odd hour every now & then trying to get it to work but to no avail.
I have even watched youtube videos of very thick Southern US accents & everything seems to work - a fairly standard Scottish accent throws the system completely.
It's not just car electronics - my sons & their families are all into Apple & seem to run their entire life via a phone - settting up my new phone 3 weeks or so ago my son was going to install any manner of applications - ended up with the odd App - stayed away from CC/Debit card payments, on-line everything & settled for phone, texts & a wee bit of web browsing + whatspp to see photos of the grandkids!
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As I said upthread, my TPMS takes 30 minutes driving to recalibrate itself after a reset. There are several questions on the cars dedicated forum asking why it has alarmed soon after a reset, usually resolved by a reference to the handbook page. The confusion is probably caused by the display showing "initialization completed" immediately after a reset.
Last edited by: Old Navy on Wed 19 Oct 16 at 08:27
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Missed the edit.
If the recalibration fails to any reason the system alarms at the end of the 30 minutes, which does not have to be continuous driving.
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>> As I said upthread, my TPMS takes 30 minutes driving to recalibrate itself after a
>> reset. There are several questions on the cars dedicated forum asking why it has alarmed
>> soon after a reset, usually resolved by a reference to the handbook page. The confusion
>> is probably caused by the display showing "initialization completed" immediately after a reset.
>>
This certainly simplifies and takes the stress out of modern motoring.
Popping round with a tyre gauge on Sunday mornings was so complicated. And no forum to answer those inevitable questions that arose.
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I must admit that whilst I am not anti technology in cars I am struggling to see the benefit of this from m a safety pint of view. A slow puncture does not constitute an immediate danger and will be picked up by a weekly check as CP says. A sudden puncture caused by hitting debris on the road say will still pose the same immediate danger with or without a warning light.
I suppose if you never check your tyre pressures it might seem a good idea but surely everyone here does that regularly?
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>> A slow puncture does not constitute an immediate danger and will be picked up by a weekly check as CP says.
>>
I think you have just covered 0.001% of the population whoever look at their tyres.
After what time is a slow puncture a danger?
>> A sudden puncture caused by hitting debris on the road say
>> will still pose the same immediate danger with or without a warning light.
>>
There are plenty of folks out there who have no idea and will continue on a flat tyre.
>> I suppose if you never check your tyre pressures it might seem a good idea
>> but surely everyone here does that regularly?
>>
It is a great idea and yes interested folks like readers here keep an eye on their tyres.
With low profile tyres as you know is very difficult to see when pressures are low.
I have just been advising a lady who having bought a nice new BMW has had two flats in a few days The TSP alarmed and she paid out £300 x2 but asked for help at the first warnings.
I am in favour of more auto warning systems plus the washer bottle fillable from outside and in general lock the engine compartment for 99% of folks.
rpI n t
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>> I suppose if you never check your tyre pressures it might seem a good idea
>> but surely everyone here does that regularly?
Most probably, but I do know people who never bother to check their tyre pressures. They also never open their bonnet either.
Does anyone know whether it been incorporated into the driving test yet (checking tyre pressures)?
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>> ...., but I do know people who never bother to check their tyre pressures.
>> They also never open their bonnet either.
>>
Hence my comments above.
The well qualified lass with the BMW was amazed when I showed her a simple pencil type pressure gauge.
>> Does anyone know whether it been incorporated into the driving test yet (checking tyre pressures)?
>>
My guess is no and not likely. IIRC the existing driving test includes under the bonnet that are purely "point to ! " I am surprised that just bending over, unlatching and lifting the bonnet
has not been subject to risk analysis Elf n Safety etc and banned.
Someone will tweek and raise the subject i
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>> " I am surprised that just bending over...
>> Someone will tweek and raise the subject i
Did you mean tweet or twerk?
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>> The well qualified lass with the BMW was amazed when I showed her a simple pencil type pressure gauge.
Too much information there Henry.
>> I am surprised that just bending over
like I was saying ;)
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Personally, I wouldn't want the tyre sensors but I think using the wheel sensors is a great system.
I don't understand why ON's car should throw a warning after a reset, our Popemobile doesn't. After I swapped the wheels front to back, I deliberately didn't reset, and it took 10 miles to figure it out, and there was very little wear difference. After a reset, it has not lit up.
A rear tyre at 10psi is properly dangerous, yet most drivers won't notice it. And a slowish puncture can do that in less than a week.
I think it's mandatory now, or will be, so all new cars will have one form of TPMS or another.
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Does anyone who doesn't check their tree pressures and doesn't notice a flat tyre when they are driving worry about a warning light?
Last edited by: CGNorwich on Wed 19 Oct 16 at 10:54
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Tree pressure?
Do you check that in the trunk?
Pat
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>> Does anyone who doesn't check their tree pressures and doesn't notice a flat tyre when
>> they are driving worry about a warning light?
I know of a few like that. But plenty will react to a light. My wife for example.
And increasingly, I think people actually expect the car to tell them when something is wrong.
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>> ....when they are driving worry about a warning light?
>>
>> I know of a few like that. But plenty will react to a light. My wife for example.
>>
My daughter with a string of qualification was " happy to drive with the basic red light on the dash.
I was not happy and said u turn please !!!!!!
>> And increasingly, I think people actually expect the car to tell them when something is wrong.
>>
In general I think that is the way to go as cars get ever more complicated.
Press the button for a voice to explain what the warning light means ?
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>
>> >>
>> In general I think that is the way to go as cars get ever more
>> complicated.
>> Press the button for a voice to explain what the warning light means ?
>>
What, still using old manual-correction tyres?
Haven't you heard about the new automatics? Tyres are automatically kept pumped up, and the pressures adjusted to suit all temperatures and road conditions.
It's true the units cost £1000 to replace when they fail, but that's progress isn't it?
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>> I suppose if you never check your tyre pressures it might seem a good idea
>> but surely everyone here does that regularly?
>>
I doubt it, and if we did all check our cars tyres and fluid levels regularly we would be a tiny minority that did.
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I rode back from work tonight and my mind was wandering to the sensor based system on my old BMW bike - I was riding to meet a friend the summer before last when a warning light came on and the display switched from the ambient temperature to they TPMS - showing the rear tyre slowly deflating as I rode on. Sure enough there was a sliver of a craft knife blade in the tyre. Got fixed by the AA. That could have ended badly - but as Pat says the seat of my pants would have possibly alerted me before it went that way.
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The ABS based system in the Volvo can detect when all four tyres are low - which might be why it showed all four corners in amber. If someone (*slaps dealer*) topped them up to the "eco" pressure and then calibrated it, you'll see a low reading after the pressure drops to a normal level in all the tyres.
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>>The ABS based system in the Volvo can detect when all four tyres are low
That's pretty damn clever - how does it do that?
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Because it senses that the rolling diameter of the tyre or tyres is less than it shoult be
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Hi Pat,
Not having read everyone's replies, but wanting to throw my tuppence in, I had this on my '15 D4 V70 just earlier this week. Coloured dot on the screen was different on the tyre in question though...
Difference in pressures was small when checked, so pumped up tyres, and you then have to press a 'reset' option on the screen to calibrate the new pressures and it tells you you need to drive for 30 mins to do so.
All seemed quite straight forward, but you must remember that re-set calibration.
What XC60 have you got, and apart from the extra cylinder, are you happy with it??
Lovely cars. I wanted one instead of the V70, but the new D4 engine was not available at the time for the XC60 in AWD - only 2WD and if I was going to get that car I would want it with all 4 driven wheels.
I too miss that 'thrum' of the 5 cylinder (had in my S60 years ago).......
When I got my Volvo the discount for a new V70 then was so big (as it was getting to the end of it's model life) that I could not ignore the difference, and took the V70 over the XC60 and got a top of the range V70 with lots of extras for less than the discounted price for a much lower spec XC60 with none.
Not 100% certain I made the right choice as for sure the XC60 looks much better, but having seen info on the V90 I think that will probably get my vote when the V70 eventually dies (only 45k on the clock so far, so some time to go.....)
Happy motoring Pat!
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It's a 2016 D4 SE Lux Sfd and like you it was so heavily discounted mainly because of the then 10% for being a caravan club member, we couldn't justify buying an almost new one.
It came with privacy glass and I'm getting used to that now but I tend to use the door mirrors for reversing and not the rear view mirror at all.
It's a tad annoying really!
It does so well for the size of the engine and there is almost no difference to the V70 but we can both feel the lack of the extra pot.
It handles very well and is sooo comfortable with the heated seats and even on a long journey it stays that way.
Fuel consumption is excellent overall and the technology is amazing. It will lug away in a high gear forever and the mpg just increases.
Stop/start doesn't worry me at all as it is seamless in the operation so I don't see a problem.
The electronic parking brake takes some getting used to though and I prefer to have an audible sound to tell me it's on and I live in fear of having to stop on the ramp on the Eurotunnel when going upstairs:)
The AWD option may have been a good choice if they had one available.
Last time I managed to get downstairs both times!
Really it's perfect but it just doesn't make me smile like the V70 did, it doesn't excite me when I drive it and it lacks a bit of character.
I loved the sound the old V70 made whenever I needed to get by something or get away from a tail gating vehicle behind me. That made me smile!
The XC90 was too big for us as we tend to do a lot of single track roads on holiday and it is certainly wide, but now we've sold the caravan I think maybe it will be another V70 next time.
Pat
Last edited by: Pat on Thu 20 Oct 16 at 14:46
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That sounds great Pat. The SE Lux is a nice spec!
The electronic brake I got used to and now only use it when parking, but I have an auto (my first modern one) which makes life easier in that respect, as it will with the ramp at the Eurotunnel. I guess you have 'hill-hold assist' that will stop it from rolling back for a few moments whilst you get the clutch in though?
Stop-Start is fine, and as you say, seamless.
I loved the D5 - 5 cylinder manual I had in my S60 (2005) as the engine felt more powerful (163hp) than the 184hp I have now, but I think that must also be part of the gearing, as the S60 would leap forward from 30mph in top gear, it was so flexible.
The D4 engine is fine for a 4-pot, but lacks character, but there will never be any 5+ cylinder Volvo's for the foreseeable future now :( I think 'personality' in cars is a very rare thing now sadly.
Fuel consumption of the V70 D4 is about 45 - 52 mpg depending on the trip, so pretty good for such a big car.
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That fuel consumption is good sfd, I manage to average around 43-45mpg but Ian can manage 48-50mpg easily which does cause some 'spirited discussions' ;)
It does have hill hold assist but I can't seem to trust it. I think it's because I still feel that I have a 44' loaded trailer behind me and really prefer to be in control myself in a situation like that.
It really is irrational worrying about the ramp on the Eurotunnel because I've been up it many times and never had to stop yet. The bigger problem is I can't see over the bonnet if the guideposts on the sides have been broken which they often are.
Pat
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>> Because it senses that the rolling diameter of the tyre or tyres is less than
>> it shoult be
And how does it do that?
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Mt
That had caused me to think as well. The only obvious way is to compare the actual speed derived from GPS with that the computed speed from the rotation of the wheel. But is the GPS linked to the ABS system in a relevant way?
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It doesn't need to know the speed to detect a puncture. It's detecting a change in the rotational speed. It certainly won't be using GPS as part of the check.
Last edited by: rtj70 on Fri 21 Oct 16 at 16:05
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How if all 4 wheels are the same and wrong? Which is what inspired the original Mt question.
If it is just 1, easy! most understand that.
OP
The ABS based system in the Volvo can detect when all four tyres are low - which might be why it showed all four corners in amber. If someone (*slaps dealer*) topped them up to the "eco" pressure and then calibrated it, you'll see a low reading after the pressure drops to a normal level in all the tyres.
Last edited by: sherlock47 on Fri 21 Oct 16 at 16:32
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>> It doesn't need to know the speed to detect a puncture. It's detecting a change
>> in the rotational speed. It certainly won't be using GPS as part of the check.
OK I'll try and work through it.
Say the pressure on all four tyres drops by 2psi or whatever the tolerance is. Leave to one side for the moment that an intra day temperature change can account for more than that.
The rolling radius (rr) of each tyre will decrease slightly, by an amount more or less directly related to the pressure change.
That change can be detected by the system.
Assume the actual speed is unchanged.
The revolution rate of the wheels will have increased, in unison.
If the speed is unchanged, the system could infer that all four wheels must have a reduced rr, and therefore all pressures have dropped.
However, the speed measurement is also related to the revolution rate of the wheels. It may be measured by the ABS sensor(s), using an embedded assumption about rolling radius, or it may be measuring at the gearbox output shaft, using the rolling radius and axle gearing in the function.
In both cases, the car will simply report an increase in speed. It's circular. The only way it has of detecting a change on the rolling radius of each wheel is to compare its rotation rate to that of the others, and inferring any non-common difference relates to a rolling radius change and therefore a likely pressure change unless it has a proxy for speed that is insensitive to the rr. e.g., using rpm x overall gearing x wheel size doesn't work - at the same speed, the rpm will be higher, and a higher speed will be reported.
If the rotation rate of all four wheels changes together, it will 'know' but it will see nothing different to a speed change.
GPS is the obvious independent source, but do we think that is the secret?
Now come back to temperature. A tyre at 32psi at 20C will have a pressure over 2psi lower at 5C (change in absolute pressure proportional to change in absolute temperature). That could be aimed off for by using the ambient temperature value. I'm not sure that's realistic. The tyres could have been in the shade, while the mirror housing or wherever the temp sensor is is in the sun. Running also affects tyre temperature, but not ambient temperature. In short, the system does not know the tyre temperature.
I'm quite sure it's doable, and quite prepared to believe it's been done, I'd just like to know how.
That'll be repetitive but I haven't time to edit just now.
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Ambient temperature certainly changed tyre pressures on my Passat (which had pressure monitoring in the valves) more than I expected.
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Volvo XC60 - Women and technology - rtj70
