Tpms

[James77]

TPMS went off yesterday on the weekly food run because I've just swapped back to summers so topped pressure to 36 and set TPMS going.

Anyone with a more technical mind than me know why the current iTPMS takes a age to reset. Every other car I've had sets in seconds I need c8 min run for this miserable system to go green. My V40 does it in seconds 3 series 1 series and my last xc60 can't just be difference between being I direct and direct?

[nu11eaf]

The old TPMS system had sensors in the tyres to measure the pressure so it was instant the new systen does not measure the pressure but the rolling circumforence of the tyre and requires several miles to calculate and calibrate, there are no sensors in the tyres.
This is a shortened version of a more technical answer.

[Zebster]

It needs a decent run to balance out the road curves and establish a reliable baseline for the relative wheel rotations

[gaby]

Originally Posted by James77

TPMS went off yesterday on the weekly food run because I've just swapped back to summers so topped pressure to 36 and set TPMS going.

When I swap tyres and/or change pressures, iTPMS has (until now) not seen a problem.
I wish Volvo still offered dTPMS, perhaps as an option.

[coppice]

If Volvo have moved from direct to indirect tyre pressure monitoring, why do the manuals still say there is monitoring hardware in the tyre valves? Surely indirect monitoring doesn't need any support inside the tyre?

[gaby]

iTMPS doesn't use pressure monitors, there is nothing in the tyres.
Can you specify where you read about hardware in the tyres?
I just read the MY2018 UK manual for the XC90 and I coudn't find it.

[Zebster]

Originally Posted by coppice

If Volvo have moved from direct to indirect tyre pressure monitoring, why do the manuals still say there is monitoring hardware in the tyre valves? Surely indirect monitoring doesn't need any support inside the tyre?

There are no pressure monitors in the wheels on my car. I've replaced the wheels and the original set have had the tyres removed.

The manual covers various models, some of which use direct measurement.

[coppice]

I might have been looking at the wrong manual online. When I looked again, making sure I picked the right manual for my year of V90, I only see a description of an indirect measurement system, with no mention of special hardware in the tyres.

[LexV90]

When have TPMS ever been reliable, well executed or worthwhile? It's not like Volvo SUVs are Nurburgring smashers, just can't see the point in them.

[nu11eaf]

Originally Posted by coppice

I might have been looking at the wrong manual online. When I looked again, making sure I picked the right manual for my year of V90, I only see a description of an indirect measurement system, with no mention of special hardware in the tyres.

There were not fitted to the V90 the XC90 had tyre valve sensors in cars before MY17 and some other models but from MY17 they did away with that system.