tyre pressure monitor think (again!)

tyre pressure monitor think (again!)

Author
Discussion

briSk

Original Poster:

14,291 posts

228 months

Wednesday 12th November 2008
quotequote all
we've recently switched to normal tyres after a recent puncture/worn outness of runflats.

the wife said this morning the light came on. she went to garage checked presures and they were at low end but still 'within operating range' as it were. reset it and drove about 15 miles and it didn;t come on again.

any ideas? low cold pressure? could something be up with a sensor?

Supermega

77 posts

191 months

Wednesday 12th November 2008
quotequote all
did you reset the pressure monitor after you changed the wheels?

briSk

Original Poster:

14,291 posts

228 months

Thursday 13th November 2008
quotequote all
Supermega said:
did you reset the pressure monitor after you changed the wheels?
that's a good point. i presumed they had done it... wouldn't it have been 'stuck on' if they hadn't reset it?

it's a good point though..?!

sjrainsford

11 posts

187 months

Monday 24th November 2008
quotequote all
Hi there!

The tyre pressure monitor isn't actually a pressure monitor as such, there are no pressure sensors.

Instead this system uses the wheel sensors to check wheel rotation speeds (The same sensors used for the ABS etc). If one wheel on average rotates faster than the others then it is suspected to have a flat tyre and the warning lamp illuminates.

After a tyre change, it is normally recommended that the system is reset so it can re-learn.


Supermega

77 posts

191 months

Monday 24th November 2008
quotequote all
Spot on Stu!

sjrainsford

11 posts

187 months

Tuesday 25th November 2008
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Supermega said:
Spot on Stu!
Heh, funny I should see you here!!

bobclive

18 posts

200 months

Wednesday 11th February 2009
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I would suggest you just press the reset button and leave it at that, you now have the advantage of the sensor warning you at a tyre pressure of approximately 24 PSI. This is because the walls of a none runflat tyre are softer, I believe the sensor sees the flex in the tyre wall, a runflat has thicker tyre walls and flexes less therefor the sensor reacts at about 6 PSI, you could be driving on an almost flat runflat for weeks and the inside of the tyre will be totally knackered, this is the reason they cannot be repaired, the inside of the tyre is destroyed.

I have just changed my granddaughters 17inch runflats to standard 17inch Falkens, the indicator came on as said at about 6psi on runflats, it now comes on at 24psi, the only difference between the tyres is the thickness of the walls.