Just had all four wheels refurbished.  Not sure whether the wheels and/or tyres were replaced in the same place.  I've seeing tyre warning messages about both offside wheels.  I've checked the pressures and one wheel is showing no reading whilst the other shows 0 psi.  Is there a reset button somewhere - there's no reset function in the menus.   The car is a 2015 163 TDci Titanium X Auto.   I had a message a few years ago about low tyre pressure when pressure was indeed low due to a nail, so it has worked well.  

The batteries in the TPMS sensors have run flat. On average they last between 7 and 10 years. On a 2015 car you will need to replace all 4 very soon if they are the original sensors. You can buy a set from the likes of eBay or Amazon for around £30.

If this happened directly after the wheels have been refurbished it is highly likely that the TPMS sensors were damaged while removing/installing the tyres.

If this is the case, it is basically the fault of the person who removed/installed the tyres.

On the other hand, if these are still the original TPMS sensors the life expectancy of the sensors has already passed anyway. Ford prescribes a life expectancy of 7 Years for these TPMS sensors. Anything longer is a bonus. 

The downside is that the tyres need to be (partially) removed to be able to change the TPMS sensors.

Unofix and JW1982 - thank you both for replying.  The alloy wheel place say they will probably replace them f.o.c.   Are TPMS sensors on the S-Max servicing schedule at all?  I'd rather have them replaced from time to time rather than suddenly presented with a warning klaxon and a diagram, which is what happened some years ago (in my Citroen C5) as I was in the outside lane of a motorway - not the place you want to be when you're told you've suddenly got zero pressure in a tyre.

8 hours ago, splinternet said:

 Are TPMS sensors on the S-Max servicing schedule at all?  I'd rather have them replaced from time to time

Not part of any service schedule on any Ford vehicle as far as I know.

They will generally last 7 years and very often as much as 10 years. If you replace all 4 now (recommended) then that should see you sorted for 7 years 👍