TPMS warning, but.......

[milleplod]

.......there's no monitors on my wheels. Now, I know that, in the absence of individual sensors, should a tyre start to deflate, the car throws up a warning based on the difference in rolling radiuses (or at least I assume that's what it does....).

I got the big red warning yesterday afternoon - great, new tyres only fitted a few weeks ago, another bloody puncture, thinks I! But no, all the pressures are spot on - so why would I get the warning? Any ideas?

Pete

 

[SpikyMikey]

You're right, the ABS do the TPMS thingy.
Did you reset the TPMS after the new tyres were fitted?

 

[geoffus]

It's just the fact that the pressure monitor needs resetting, since you have had new tyres its noticed a differential.

 

[Petrol Pete]

The OP seems to have a non TPMS system so it will be working on rolling radius/wheel speed measurements. My guess is if everything has been fine on new tyres for a week or two an the pressures are fine that the problem lies elsewhere. Wheel speed measurement sensor/relouctor ring fault ? Although if that were the case you might expect to see ABS fault lamp illuminated as well.

 

[SpikyMikey]

The OP seems to have a non TPMS system so it will be working on rolling radius/wheel speed measurements. My guess is if everything has been fine on new tyres for a week or two an the pressures are fine that the problem lies elsewhere. Wheel speed measurement sensor/relouctor ring fault ? Although if that were the case you might expect to see ABS fault lamp illuminated as well.

Could be, but with mine when I had new boots put on it and forgot to reset the dash, I was surprised how many miles it took before the warning popped up.

 

[BigJase88]

Check tyre pressures again before you reset

 

[Petrol Pete]

I'm a bit confused (not difficult these days) . Does the OP car have TPMS monitors on the valves in the wheels or not . ?

 

[BigJase88]

I'm a bit confused (not difficult these days) . Does the OP car have TPMS monitors on the valves in the wheels or not . ?

There are 2 systems

Overall tpms which uses wheel speed sensors and no valves in tyres

Or individual tpms which uses valves in tyres.

The OP has the overall with no seperate tpms valves. It can still identify a puncture but will not tell you which one or what the pressures in the tyres are

 

[milleplod]

I didn't reset it straight after the new tyres were fitted as I never got the warning come up - I've probably done around 500 miles since on them, yesterday was the first time it's appeared. Pressures checked again this morning and they're fine, so presumably it's a somewhat delayed reaction!

Oh, my car has

477	TIRE PRESSURE LOSS WARNER

on the data card.

Pete

 

[Germgh0st]

It's a deflation detection system, as opposed to a pressure monitoring system. It uses ABS sensors and other electronics to calculate the radius of the wheel and alerts to any changes in any wheel. My first Focus ST had DDS before the newer models had TPMS. Unlike TPMS, DDS needs to be reset everytime you do something that might change the tyre pressure, like adding a bit of air, because DDS needs a baseline.

 

[milleplod]

It's a deflation detection system, as opposed to a pressure monitoring system. It uses ABS sensors and other electronics to calculate the radius of the wheel and alerts to any changes in any wheel. My first Focus ST had DDS before the newer models had TPMS. Unlike TPMS, DDS needs to be reset everytime you do something that might change the tyre pressure, like adding a bit of air, because DDS needs a baseline.

Interesting, thanks. Must say though that in the past I've dabbled with pressure changes and never had the warning come up.

Pete

 

[Germgh0st]

Interesting, thanks. Must say though that in the past I've dabbled with pressure changes and never had the warning come up.

Pete

From what I remember, of the Ford system anyway, because it doesn't record the actual pressure more the 'roundness' of the tyre, it often doesn't give a warning unless there's a significant change from the baseline. I have no idea what would be defined as a significant change though.

 

[BTB 500]

I always assumed these systems were pretty basic, being triggered by a difference in rpm (reported by the ABS sensor) between one wheel and the others (the overall diameter would reduce as the tyre pressure fell, so it would have to turn faster at any given road speed).

 

[Petrol Pete]

There are 2 systems

Overall tpms which uses wheel speed sensors and no valves in tyres

Or individual tpms which uses valves in tyres.

The OP has the overall with no seperate tpms valves. It can still identify a puncture but will not tell you which one or what the pressures in the tyres are

I am aware of the two systems. just couldnt decipher which one the OP had based on his original post then some of the replies given suggesting 're setting' his TPMS.