Topic

Titus
By: Titus
Posts: 5307
Joined: 12/01/07

Puncture Warning

Posted: Jun 27 2011 Views: 39


Recently heard of someone who was driving along (not in a Mazda, as far as I know) and a message lit up "Please pull over - you have a puncture in your rear nearside tyre."  "Cobblers!" thought the driver "Car feels fine to me!"  However, after a while he decided to stop and look.  Sure enough - puncture, rear N/S tyre.

He did not have any kind of tyre pressure monitoring system fitted, but apparently on his car, the wheel rotation sensors are continually monitored by the control unit, and if it notes one wheel consistently beginning to rotate very slightly faster than the others over a period of time, it works out that the rolling radius has decreased slightly, almost certainly indicating a slow puncture.

OK, not as sensitive, as certain or as swift-to-act as a tyre-pressure sensing sytem, but simple, elegant and cheap since it uses existing sensors and just processes already-available information intelligently.

Maybe I'm just out-of-touch and this is old hat, but I was impressed.

 

Replies

  1. /My-Page/?userId=12186

    RE: Puncture Warning

    My last Focus ('08) had it as an optional extra. I think it cost £50. Quite expensive for a software activation using existing sensors.


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    Posted: Jun 28 2011 By: Jono   Posts: 290
  2. /My-Page/?userId=10174

    RE: Puncture Warning

    One of my Citroens had this as standard and it was very effective. However it developed a fault in the tyre vale and it was and arm and two legs to replace. The alternative was to remove the valve and fit an "ordinary" one. This however made the sensor indicate all the time that the tyre was punctured.--------------Yell


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    Posted: Jun 28 2011 By: Grumpyolfella   Posts: 1390
  3. /My-Page/?userId=8339

    RE: Puncture Warning

    28/06/2011 07:54:55, Grumpyolfella said:

    One of my Citroens had this as standard and it was very effective. However it developed a fault in the tyre vale and it was and arm and two legs to replace. The alternative was to remove the valve and fit an "ordinary" one. This however made the sensor indicate all the time that the tyre was punctured.--------------Yell


    This sounds like a direct-pressure-monitoring system, precisely NOT what I described, and your story illustrates exactly the kind of problems such [expensive and complicated] systems can create - just the opposite of the system I described, which uses no special tyre valves, is cheap and simple and just uses the existing wheel-rotation sensors.

     

    Posted: Jun 28 2011 By: Titus   Posts: 5307
  4. /My-Page/?userId=14318

    RE: Puncture Warning

    Minis have the same system, working via the ABS sensors at each wheel. when you correct the puncture or simply reinflate a "kerbed " tyre you have to reset the system via a steering column mounted control. The system works very well and is maintenance free, except when the ABS unit fails, as it often does on VAG group and BMW cars, then it requires a £1500 unit replacement and a recoding of the ECU.

    Posted: Jun 28 2011 By: iconicagain   Posts: 8