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Tpms
- Thread starter ibroker
- Start date
Later UK E89s had them
Lot of expensive faff to retrofit
Lot of expensive faff to retrofit
Don't know why anybody would want to retro-fit the sensor type TBH.MarshMA10 said:
If you don't have these, then you have the ABS-based system. They do the same thing, only in different ways. And the ABS type is cheaper and more reliable. Changing wheel sensors when the batteries/ sensors die is a PITA as the tyres have to come off.
I would rather have neither. TPMS is a pain IMO. I seem to constantly have a warning on one car or another because one tyre is 1/4 psi different to the others. :roll:
I had a good system on my old C5 Vette which was just useful for keeping an eye on pressures generally and did pick up some pressure change during track day tyre heat. Definitely annoying if a sensor runs out of battery but only happened a few times over 10 years, and is/was a nice feature 99% of the time.
…..But I agree I certainly wouldn’t bother doing the retrofit if it’s a faff / more than a case of buying the valves and fiddling a code.
…..But I agree I certainly wouldn’t bother doing the retrofit if it’s a faff / more than a case of buying the valves and fiddling a code.
ibroker said:
There are two systems in the UK for E89s..
Earlier pre 2014? E89s use FRFM..run flat monitor…there are are no sensors in the tyres /wheels…there deflation is ca; ulatec by the DSC system detecting the lower pressure wheel is rotating faster than the other 3 wheels..
Later TPMS come in..tyre pressure monitoring system…each tyre / wheel has a valve with built in radio transmitter and pressure sensor…that sens the pressure in each tyre to a box..the RDC..which then flags a message up on the display if a pressure drops below a certain amount…
So earlier system deduces pressure by relative speed of wheels..the latter system by actual,pressure measurement..
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Easy to spot as TPMS has metal shanked valves with a nut at the bottom of the valve stem…runflat has rubber valves..hence my question in the first place..
Comprendo?
B21 said:
Or in English for the mere mortals among us:
FTMS: Flat Tyre Monitoring System uses no sensors in the wheels. The ABS counts the rotations of the wheels. Pressure loss = less rotations in relation to the other wheels.
TPMS: Tyre Pressure Monitoring System has sensors inside the wheels which are attached to the valve stems. If the valve stems are metal and solid (as opposed to rubber and wobbly) they are sensors. The sensors send a signal constantly and a receiver picks up the signal on every rotation.
Same thing only the latter is more complicated and can give more info, such as individual pressures.