XC60: Tyre pressure system Service required
Discussion
E-bmw said:
You make no mention of the actual tyre pressures.
No, but they are all correct. (The message isn't about tyre pressures, it's about the "Tyre pressure system".) My understanding is that as it's an indirect system, the absolute pressures aren't relevant. It's only detecting a change in tyre circumference, compared to those values stored during a calibration.
E-bmw said:
Don't assume that just because you have new tyres that the pressures are correct.
No - but surprisingly, they were. The extra tread depth (and hence change in circumference) prompted a different warning, hence the need to recalibrate.Ok, you say they are correct & that the tyre pressure aren't relevant as they are indirect.
I am sorry but they are 100% relevant, as that is how it works.
Top tip:
When you check the pressures use the PSI rating, not the BAR rating.
Yes, they are the same but 0.1 bar is 1.5 psi so if you set them at the bar pressure they could be 1.5 psi away from each other, which on many systems is enough on its own to set the system off.
I am sorry but they are 100% relevant, as that is how it works.
Top tip:
When you check the pressures use the PSI rating, not the BAR rating.
Yes, they are the same but 0.1 bar is 1.5 psi so if you set them at the bar pressure they could be 1.5 psi away from each other, which on many systems is enough on its own to set the system off.
E-bmw said:
Ok, you say they are correct & that the tyre pressure aren't relevant as they are indirect.
I am sorry but they are 100% relevant, as that is how it works.
Can you explain how incorrect tyres pressures could cause the tyre pressure monitoring system to fail, rather than report that the pressures are wrong?I am sorry but they are 100% relevant, as that is how it works.
silentbrown said:
E-bmw said:
Ok, you say they are correct & that the tyre pressure aren't relevant as they are indirect.
I am sorry but they are 100% relevant, as that is how it works.
Can you explain how incorrect tyres pressures could cause the tyre pressure monitoring system to fail, rather than report that the pressures are wrong?I am sorry but they are 100% relevant, as that is how it works.
It sounds to me like it has not accepted the calibration.
silentbrown said:
E-bmw said:
Can you explain to me why you think it has failed?
It sounds to me like it has not accepted the calibration.
It sounds to me like it has not accepted the calibration.
Sounds like the garage has messed up with tyre sensors to me.
I could be wrong, but that is what it looks sounds like.
ETA.
Inferred TPMS systems don't normally have a display for each wheel/tyre.
Edited by E-bmw on Tuesday 9th July 09:51
E-bmw said:
That doesn't look/sound like an inferred TPMS system.
Exactly. Which is why I'm confused. I'm 99.9% sure there are no pressure sensors in the tyres, and 'direct' systems normally display absolute pressures in PSI.Screenshot (and quotes) frm here.
https://www.volvocars.com/uk/support/car/xc60/16w4...
"The TM (Tyre Monitor) system senses tyre rotation speed in order to determine whether the tyres have the correct tyre pressure."
"The status is colour-coded for each tyre in accordance with the following:
All-green: the system is operating normally and the tyre pressure in all tyres is slightly above the recommended level.
Yellow wheel: corresponding tyre's pressure is too low.
All wheels yellow: two or more tyres have pressure that is too low.
...etc"
silentbrown said:
... on a 2017 XC60, which AFAIK has indirect TPMS (wheel speed based)???
This, after a recalibration and new tyres.
No ABS/ASC errors, so I don't think it's a wheel sensor/ring.
Will try recalibration again, but it's an odd one.
Had exactly the same thing on my 2019 V90 CC recently after new tyres. Same warning and the recalibrate option was greyed out. After a few miles and couple of engine offs and ons I was able to recalibrate and warning hasn't come back.This, after a recalibration and new tyres.
No ABS/ASC errors, so I don't think it's a wheel sensor/ring.
Will try recalibration again, but it's an odd one.
Kwik Fit should probably have reset the system but they should have also fitted one of the directional tyres in the correct, er, direction. My fault for using them I suppose.
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