Be as skeptical as you want, but there are a plethora of tools to monitor function, reset and perform battery checks on the TPMS.
TS58R TPMS Tool Kits
TS58R TPMS Tool Kits <div class="container"> <p>All-in-One TPMS Solution</p> <p>With the portable TS58R in hand, technicians will be able to view Sensor Battery Life, Tire Pressure, Broadcast Frequency, Sensor ID, as well as tirewww.bendpak.com
Maybe that 2% includes the gen 1 CX-5's that work based on wheel speed?That last part, works with 100% of sensors but only 98% of vehicles? What of the remaining 2%? It works with all possible sensors but not that 2%?