TPMS- how does it work?

Thinking about fitting aftermarket alloys. With TPMS ( tire pressure monitoring system) how does it actually work.

I've seen sensors listed at 433hz. Is this UK spec, and do they automatically find the car if you fit them in an aftermarket wheel?

What happens if you don't fit them?

Are they the valve stem that you fit the valve caps to?

TPMS is a pressure sensor fitted inside the valve stem with a small RF transmitter on it. I fitted a set of LR sensors to my 1st Evoque and they look like 1"x 2" x 3mm thick oblongs that are fitted inside the rim with their own biult onn valve stem. Provided you get the right ones for your car my experience was seemless when changing between winter, offroad and summer pattern tyres all on their own rims with TPMS fitted, those were on my 1st Evoque. Now that TPMS is mandatory on all new cars I don't see any reason why they have changed the design. I have a set of brand new RRS SVR 21" wheels with unused tyres sat at home and they all have TPMS built in so I'm hoping that the TPMS system on my RRS is the same to set up as the Evoque's was - that is, fit wheels and drive off, simples! The LR handbook for my 1st RRE had several pages of how to set them up but the tyre place who changed the wheels over for me said "the handbook is wrong no need to do any driving around coding sensors to system, just drive off and it will work, we do loads of cars with the same system" I have never had a problem nnot doing the long drawn out method listed in the 2011MY Evoque handbook. I'm sorry but I don't know which frequency they use but I'm sure that if you asked Dan@Duckworths, one of our sponsors, he would be pleased to tell you and give you a competitive quote for genuine LR sensors working on the right frequency for your car

Thanks. That's explains the system comprehensively. In contact with Dan regularly so will ping him a mail.

Do you know what happens if they are not present? ( not planning this, just interested)

Your dash TPMS warning light will show. If your car was built with TPMS as standard (I had it as an option on my first RRE but it was standard on my 2nd one built in March 2014) be careful of the insurance implications of driving without it working, on cars built after Jan1 2013 (IIRC) it is mandatory to have it.

(24-01-2016 07:30pm)XFullFatTim Wrote:  Your dash TPMS warning light will show. If your car was built with TPMS as standard (I had it as an option on my first RRE but it was standard on my 2nd one built in March 2014) be careful of the insurance implications of driving without it working, on cars built after Jan1 2013 (IIRC) it is mandatory to have it.

Has anyone tried the ones you can get from Maplins that you can control / monitor via your I phone?

(24-01-2016 07:30pm)XFullFatTim Wrote:  .......on cars built after Jan1 2013 (IIRC) it is mandatory to have it.

My April 13 build is "LESS TPMS" confirmed as per Topix

You cannot rely on TOPIx being correct. This has been confirmed by LRCR.

Also it may be after 1st Jan 2014 not 2013

Think it is 2014. Anyhoo, got some 5 new oem ones ( I have a matching 20" and tyre ready to mount), so one for the spare and 4 ready for whatever alloys I buy.

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Although, now just seen there are 2 sorts. Doh! Think I've bought the right ones! Anyone know why there is a smaller one and a larger sensor?

The pre 2014 version is different to the post 2014 version, different system with different software and much more info available with the later system. Basically all that the pre 2014 system did was tell you that a tyre was deflating, it didn't tell you any pressures, the current version has an info screen in the dash that shows the recommended pressure for each wheel and the actual pressure as well as letting you know that a tyre is deflating rapidly.