Citroen C4 Cactus Crossover Forum banner
1 - 20 of 32 Posts

Registered
Joined
45 Posts
Discussion Starter · #1 ·
Hello again just a quick one how often do you put air in your tyres my cactus has just reached a 1,000 miles and the tyre pressure warning light as come on any one else had this.
 

Registered
Joined
735 Posts
I think it must mean you have to put air in the tyres :(
 

Registered
Joined
644 Posts
Our car has 16,000 miles on the clock (we've done 5,000) and the light has never come on. Husband does check pressures regularly tho and adds air when car is heavily loaded (and takes it out again when it's not!)
 

Registered
Joined
725 Posts
Mrsstuzilla said:
Our car has 16,000 miles on the clock (we've done 5,000) and the light has never come on. Husband does check pressures regularly tho and adds air when car is heavily loaded (and takes it out again when it's not!)
You have to do something in the settings each time you adjust any of the tyre pressures. If you don't it won't work. I'll have a look at the manual to check what page it is on.

Edit.
It's on pages 131/132
 

Registered
Joined
128 Posts
I check mine at least once a month. I don't know how much under pressure they have to be before you get a warning so I think it's good practice to keep them correct, especially as it affects fuel consumption.
 

Registered
Joined
725 Posts
StevieJ said:
I check mine at least once a month. I don't know how much under pressure they have to be before you get a warning so I think it's good practice to keep them correct, especially as it affects fuel consumption.
When you check them, do you get much variation?
 

Registered
Joined
128 Posts
The2ems said:
When you check them, do you get much variation?
We have the 110 Flair model with 17" rims and the pressure should be 230 KPa (2.3 Bar/34 PSI). Last time I checked them two of the tyres had lost a bit of pressure, the lowest being about 210. Doesn't sound much I know but when converted is about 30 PSI - so 10% ish under pressure.

Just did a bit of research and found this "tyre manufacturer Goodyear claims that if your tyres are 20% under-inflated, you'll use 10% more fuel", so it pays to check them regularly.
 

Registered
Joined
725 Posts
StevieJ said:
The2ems said:
When you check them, do you get much variation?
We have the 110 Flair model with 17" rims and the pressure should be 230 KPa (2.3 Bar/34 PSI). Last time I checked them two of the tyres had lost a bit of pressure, the lowest being about 210. Doesn't sound much I know but when converted is about 30 PSI - so 10% ish under pressure.

Just did a bit of research and found this "tyre manufacturer Goodyear claims that if your tyres are 20% under-inflated, you'll use 10% more fuel", so it pays to check them regularly.
That's interesting. When I have new tyres on my C5 a few years ago, I had them inflated with nitrogen. Apparently it is drier than air, so doesn't rust the inside of the rims. And the molecules are larger than air molecules, so they don't seep out through the tyre walls. Trouble is you can only re inflate them with nitrogen when checking the pressures.
 

Registered
Joined
8 Posts
My warning lights come on after I adjusted tyre pressures as I'd neglected to reset the tyre monitor. So I asked my local Citroen Dealer what were the
tolerences +/- in the tyre pressure before the warning monitor would activate the sensors,no one seemed to know!
Cactus Flair 1.2 pure tech 17" wheels Obsidian Black
 

Registered
Joined
116 Posts
Burky said:
Hello again just a quick one how often do you put air in your tyres my cactus has just reached a 1,000 miles and the tyre pressure warning light as come on any one else had this.
Always worth checking the tyres for a nail etc. My pressure warning came on, so I checked and the rear nearside was down a bit. Inflated and re-set the monitor but the following day it came on again. Had a closer look at the tyre and discovered part of a nail embedded in the tyre. Cost 拢17 for a repair from my local tyre place. Shows that the system works really well! :)
 

Registered
Joined
644 Posts
It won't let you reset when you're going along and that was the only time I've remembered so far. Will wait until tyres are cool and reset in the morning.

All the tyres were down on what they should be when he checked the other day but I'm guessing as they all went down by about the same amount that's why the warning didn't sound.
 

Registered
Joined
626 Posts
I think the key thing to note here is that as the ambient temps are dropping, your tyre pressures will also be dropping (only slightly).

Dont forget the pressures quoted are "Cold Pressure" so the tyres should only be checked and reset before using the car, on sometime after use.
 

Registered
Joined
105 Posts
I had the notification pop up on my touchscreen and the warning icon came on in my other screen. Got out and checked and all 4 seemed ok.

My question is: So it doesn't tell you in which tyre the problem is? and how does it work... calculating the revolutions maybe?
 

Registered
Joined
472 Posts
Mine has only come up once, I checked them and all 4 were down exactly the same. Top up, reinitialise, job done. It works by rotation speed I believe, same as my old bmw mini. If they're not equal pressures or if one is lower than what you initialised the rotational speed of that wheel will differ from the correct one/ones.
 

Registered
Joined
55 Posts
Kevin said:
and how does it work... calculating the revolutions maybe?
Something like that...has to do with the ABS-sensor.

If the pressure drops 20% the system must alert (the law - if they work below 20% I don't know)

Stolen from Wiki
Wikipedia said:
Indirect TPMS do not use physical pressure sensors but measure air pressures by monitoring individual wheel rotational speeds and other signals available outside of the tire itself. First generation iTPMS systems are based on the principle that under-inflated tires have a slightly smaller diameter (and hence higher angular velocity) than a correctly inflated one. These differences are measurable through the wheel speed sensors of ABS/ESC systems. Second generation iTPMS can also detect simultaneous under-inflation in up to all four tires using spectrum analysis of individual wheels, which can be realized in software using advanced signal processing techniques. The spectrum analysis is based on the principle that certain eigenforms and frequencies of the tire/wheel assembly are highly sensitive to the inflation pressure. These oscillations can hence be monitored through advanced signal processing of the wheel speed signals. Current[when?] iTPMS consist of software modules being integrated into the ABS/ESC units.

iTPMS cannot measure or display absolute pressure values, they are relative by nature and have to be reset by the driver once the tires are checked and all pressures adjusted correctly. The reset is normally done either by a physical button or in a menu of the on-board computer. iTPMS are, compared to dTPMS, more sensitive to the influences of different tires and external influences like road surfaces and driving speed or style. The reset procedure, followed by an automatic learning phase of typically 20 to 60 minutes of driving under which the iTPMS learns and stores the reference parameters before it becomes fully active, cancels out many, but not all of these. As iTPMS do not involve any additional hardware, spare parts, electronic or toxic waste as well as service whatsoever (beyond the regular reset), they are regarded as easy to handle and very customer friendly.[4]

Since factory installation of TPMS became mandatory in November 2014 for all new passenger vehicles in the EU, various iTPMS have been type-approved according to UN Regulation R64. Examples for this are most of the VW group models, but also numerous Volvo, Opel, Ford, Mazda, PSA, FIAT and Renault models. iTPMS are quickly gaining market shares in the EU and are expected to become the dominating TPMS technology in the near future.

iTPMS are regarded as inaccurate by some due to their nature, but given that simple ambient temperature variations can lead to pressure variations of the same magnitude as the legal detection thresholds, many vehicle manufacturers and customers value the ease of use and tire/wheel change higher than the theoretical accuracy of dTPMS.
 

Registered
Joined
55 Posts
In the year I've had mine, it only came on when ever i swich from winter to summer tyres (or vice versa).
 

Registered
Joined
32 Posts
Interesting note re filling your tyres with nitrogen: it prolongs the life of the tyres as the nitrogen will
not cause deterioration of the rubber in the tyres as much as with 'standard 'air.

Nitrogen is more stable so pressures will not fluctuate as much.

It's often the case that owners will fit green valve caps when tyres are filled with nitrogen. This is to alert
garage staff of that fact.

It's OK to top up nitrogen filled tyres with air, although this would dilute the effectiveness.

Regarding the tyre pressure monitoring system, I've had that on several previous cars and it is usually an impact
of some sort - encountering a pothole for example - that causes the monitor to be activated.
On one occasion it appeared to be extreme cold that triggered it.

And sometimes there didn't appear to be any obvious reason.

Naturally, each time it's crucial to find a filling station to check everything's OK.
 
1 - 20 of 32 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top