Yes, canadian rangers have the TPMS. They are band style sensors (its a strap on the inner wheel)
I do think most rapair shops can diagnose the TPMS failure, my local OK Tire is equipped to read the TPMS ''code'' - they can know which sensor has failed.
If as you say, the light is constantly on and the pressures are OK - 30psi on our model year - 3 options are available; 1. one or many of the sensors is dead, 2. The wheels have been changed, and no sensors are in them, or 3. The TPMS module is dead