TPMS Light On Diagnosis and Fix Lexus GX 470

In today's adventure we figure out why our TPMS light is on, determine which tire is the actual culprit and resolve it.
Helpful note. If the TPMS warning light is blinking, that means the sensor is not registered or more than likely the battery is dead and needs replacing.
If the light is solid, that means one or more of your tires is low.
Tools used were a tire pressure gauge, air compressor and extension cord.
Along with the on-board tool kit that has uses the jack handle to raise and lower the spare tire from it's storage location under the back of the Lexus GX470.
We used an optional scan tool to confirm that it was our spare causing the problem. This isn't required but can be handy and helps justify purchasing to your better half.