[Richard230]

Could one or both of the TPMS batteries be on their way out? On some versions of the system the battery can be replaced and in newer versions, as used on my RS, the battery is potted in the device and the entire TPMS must be purchased directly from BMW. Then you need a franchised dealer to reset and calibrate the new TPMS equipment.

 

[Richard230]

I have read the compensation is set relative to 68F/20C but are we confident that is correct? Given the bike has an ambient air temperature sensor it would seem very easy to base the temperature compensation against this figure and not a constant which if I understand your posts correctly Dave should, in part, address your objections to the system.

Out of interest I did some checks this weekend, ambient temp was 18-20C, cold tyre pressure with gauge gave 35.5/42.5 (front/rear). Set off and TPMS showed 36/42 which changed to 37/43 for the next 2 hours of my ride (not fast mainly 30-50 mph in traffic) got back home and checked pressure hot and 38/46 with gauge. In this scenario I would say the temperature compensation has some worth but of course the ambient temperature was the same as the temperature that BMW are said to be using as their relative temperature. It may prove different if temperature was considerably colder.

When I get the time I'll attempt to code out the temperature compensation see if the code does what it says on the tin.

However all that said I'm in complete agreement with all those who believe TPMS is no substitute for regular manual tyre checks and the real benefit is alerting the rider to a change in pressure (puncture) before it's actually felt in the handling.

While I don't depend on the pressure reading of my TPMS that came with my 2016 BMW R1200RS, it does show the exact same PSI air pressure as I measured in my garage with an accurate air pressure gauge before riding off for the day. And that pressure reading stays the same throughout my ride no matter what the ambient temperature or riding speed. So if nothing else, it is very well compensated.