tyre pressure monitoring system

[Jazzdriver]

How does this work please?

The warning light came on on my new Jazz.  All the tyres were a bit low, one more so.  I have added air and will monitor the situation.

The manual only has information about the warning light.  How does the system work?  Where are the sensors?  If I were to fit steel wheels with winter tyres, would I have to do anything about the sensors for them to work with the new tyres and wheels?

Thanks.

[Jazzdriver]

Since posting, internet research suggests that it may work via the ABS measuring the speed of the wheels: if one tyre has low pressure it spins faster, owing to a smaller circumference.

[Eddie Honda]

This thread on that fitted to the Accord will give a clue as to the operation of the system:

http://hondakarma.com/threads/2014-honda-accord-tyre-pressure-monitoring-system-tpms.7892/

[culzean]

On Jazz and Civic in UK they work from ABS sensors on each wheel - as the pressure drops in a tyre the apparent radius of the wheel decreases (distance from centre of axle to ground gets less because of 'flat spot' at bottom of tyre where it touches the road) and the speed of rotation increases slightly.  system monitors all 4 wheels and looks for a difference in rate of pulses arriving from each wheel.

It is very accurate as I have had to reset mine when I had two new tyres fitted to car.

look in the handbook under 'multi information display' and it will tell you how to reset it if you need to because of new tyres etc.

The only slight disappointment with the system is that it does not tell  you which wheel is detected as being suspect.

[Jazzdriver]

This thread on that fitted to the Accord will give a clue as to the operation of the system

Thanks.  But that thread speaks of a monitor in the Accord's tyres, whereas the Jazz's system seems to work using the ABS monitoring of the wheels' speed.

[Eddie Honda]

Ahh, I see that indirect measurement has made a comeback. Apologies.

So if it indirectly measures the tyre pressure by directly measuring the wheel speed, it saves a few quid in sensors and doesn't actually tell you what pressure they are? Only if there is a measurable difference somewhere in what it is initially/reset calibrated at? If it was very accurate then I can only guess that the light would come on all the time. If it had plenty of acceptable slop in it, then it would stay off unless the difference got really bad.

It'd have to have plenty of acceptable slop in the measurement given that ambient temperature, running temperature, tyre growth, variation in loading and other such variables are going to give quite a range of rotational speed measures amongst all the background noise to filter out of cornering, braking and acceleration.

What if all the tyres are underinflated?

I'll stick with my tyre pressure gauge and getting off my backside, unscrewing those valve caps (including the spare) and check them myself thank you very much. 

 

[John Ratsey]

What if all the tyres are underinflated?

I'll stick with my tyre pressure gauge and getting off my backside, unscrewing those valve caps (including the spare) and check them myself thank you very much. 

I agree that routine visual inspections and manual checks of tyre pressure should be carried out.

I presume the underlying intention of the warning system is to draw attention to what is probably a puncture before the pressure gets so low that the driver notices the problem either due to handling difficulties (potentially dangerous) or unexpected noises (and possible tyre damage - not good when there's no spare wheel). I've lost count of the times when I've followed another vehicle where I could see a soft tyre but the driver was (I assume) oblivious of it.

[culzean]

Ahh, I see that indirect measurement has made a comeback. Apologies.

It'd have to have plenty of acceptable slop in the measurement given that ambient temperature, running temperature, tyre growth, variation in loading and other such variables are going to give quite a range of rotational speed measures amongst all the background noise to filter out of cornering, braking and acceleration.

What if all the tyres are underinflated?

I'll stick with my tyre pressure gauge and getting off my backside, unscrewing those valve caps (including the spare) and check them myself thank you very much. 

You would have to be the unluckiest driver in the world (or on the run from police and just run over a stinger) to have all tyres puncture at the same time.  I assume that rather than checking absolute values of speed of rotation the system looks for differences from the average of all 4 wheels. All the tyres are subject to the same ambient temperature and heat due to driving etc. and pressure would change in them all at same time, so no problem there.  As I said, I had 2 new tyres on the same axle,  the old ones about 2mm tread, the new ones about 8mm, and system display showed a warning icon, so it can easily detect 3mm difference in radius of the tyre.  Most electronic measuring systems (including MPG display) do not update display continuously, but have a 'sampling rate' of at least 10 seconds, this should take care of transient changes to the tyres due to hitting speed bumps, braking etc.

Personally I look at all four tyres every time I go to or leave the car (just a habit) and have caught a 'soft' tyre that way. As you say, there is no substitute for a pressure gauge and visual checks, and I always carry a footpump in the boot,  but if a problem happens when you are driving the 'indirect monitoring' system will pick it up.  A few years ago there were some valve caps with LED's that showed green or red when pressure was OK or low,  may still be on the market, but I imagine you would have to replace the tiny batteries fairly frequently for them to be any good - but you still couldn't see them when you were actually driving the car. .

update,  these LED caps are still available  http://www.tyre-pressure-alert.co.uk/

or a low tech version  http://www.amazon.co.uk/Pressure-Monitor-Valve-Sensor-Indicator/dp/B00KMOWPSO

[guest4871]

Could someone please indicate:

Which Jazz models have the tyre pressure monitoring system as standard?

Where is the reference to the tyre pressure monitoring system in the manual?

Have I got another missing Honda feature..........):-(

Many thanks.

[csp]

Some dealer websites now list Tyre Pressure Monitoring on all new Jazz models including the 1.2S but I could not find it on the Honda website under Jazz Specs. I guess it has been added at some stage, I have not seen it on my 62 Reg 2012 Jazz ES but will have a look in the manual later.

[RichardA]

As of 1st November 2012, all new-type vehicles will be required by EU law to have a pressure based tyre pressure monitoring system installed. This applies to the road wheels, not the spare

By November 2014, all new passenger vehicles will have to have TPMS installed by the manufacturer

http://www.techeurope.co.uk/tech/news/view/35/European-legislation-on-TPMS-imminent

[Jazzdriver]

I now see that the handbook for my Jazz refers to the system as having sensors in the wheels.  It says that if you buy new wheels they must be able to accommodate the sensors.  I am hoping that this is not correct and that the system is ABS based, as I want to buy a spare wheel.

If the system were sensor based, would it not tell you which wheel was low, instead of just telling you that there is a problem?

I have only had my new Jazz a short time and the light has come on for a second time.  Last time a tyre had a screw through it.  Kwik Fit repaired it for £28.50.  Now the light is on again. 

[lexi]

 
  To get full system and not the budget type fitted to Jazz, you need a whole lot more complication.
      My French Luxobarge has the full system. Voice warning with flashing car logo with the 4 wheels displayed and the low tyres flashing with the actual pressures of all tyres.  For that there is a mahoosive computer sits under the car

[Jazzdriver]

My car is 2015 model year.  It looks as if at sometime Honda changed the Jazz system from an ABS system to a tyre sensor based system.  The handbook says that you need special wheels and that these are available from Honda.  I bet they are.

Two punctures in a matter of weeks means that I am very keen to get a spare, but it looks like I will have to pay top price to get one from Honda.  Does anyone know how these wheel based sensors work?  Can you get wheels with sensors built in and which will work with the Jazz, apart from buying them from Honda?  (I have googled, but not got far.)  Thanks.

[madasafish]

There are lots of TPMS systems all different. Some work on a leak reducing the tyre diameter.. others on measuring pressure..

No idea what Honda have. Usually they are expensive...