Now that I've gotten this sidelined C14 closer to road-ready I'm seeing a tire pressure warning from the front tire. Both tires are fairly new with good tread and they hold pressure well (both were still right on 42psi after 2 stationary weeks in wildly swinging spring Canadian temperatures), so this isn't a low tire pressure issue, it's a sensor battery issue.
COG has a very handy thread on it here. The key take-aways here are: TPMS appears to be very temperature sensitive and can get crusty when not used for some time as this spider nest covered bike has. Once warmed up, TPMS can come back to life. I only went around the block on the bike yesterday and it was only 8°C at the time, so not exactly 'warm'. As one poster mentions, he's ridden for decades without TPMS so if it's not working it isn't the end of the world. For me, the best advice here is how to turn off the panicky dash warnings that prevent you from seeing anything else:
"a simple push and hold of the top button along with a push and release of the bottom button will light up a red warning light, and return the display function to normal when your TPMS battery is low. Also, BDF offers a simple plug in device which restores the range function and eliminates that annoying "LOW FUEL" flashing message."
It appears there are some UI (user interface) issues with how Kawasaki designed the C14 dashboard. Having only ever owned bikes with analogue dash boards I'm finding this digital fussing kinda funny. They may not be all fancy with multiple levels of information, but a well designed analogue set of clocks lasts forever, is easy to read and doesn't spaz out and distract you from riding. Kawasaki really should have thought this through better.
TPMS in the Concours works through a radio sensor inside the tire that monitors tire pressure in real time. I'd (foolishly) assumed this was somehow mounted in an accessible way around the air valve on the outside of the wheel but of course it isn't.
This handy home-mechanic goes through the process of getting into the tire in a gen-1 '08 Concours, finding the sensor and looking at the battery. Kawasaki appears to have soldered the battery in (at least on '08s), which makes replacing the battery without replacing the whole unit tricky, but this guy gives it a go anyway. Soldering onto a lithium batter is brave! They like to explode when heated.
The rear tire pressure sensor is identical:
Kawasaki SENSOR,TPMS 315MHZ Part # 21176-0748
When someone asked how expensive they are to replace in that COG thread, someone else replied, "very." They're out of stock on Amazon. New ones are going for $300CAD a pop on eBay, so yes, very.