1. Measure the temperature around the water temperature sensor.
2. Measure the resistance between terminals of the water temperature sensor.

Water temperature sensor removal/installation
Refrigerant pressure switch removal/installationMazda 6 Service Manual: Keys
WARNING
Do not leave the key in your vehicle with children and keep them in a place
where your children will not find or play with them: Leaving children in a
vehicle with the key is dangerous. This could result in someone being badly injured
or even killed. Children may find these keys to be ...
Mazda 6 Service Manual: Outside Temperature Display
When the ignition is switched ON, the outside temperature is displayed.
NOTE
Under the following conditions, the outside temperature display may differ
from the actual outside temperature depending on the surroundings and vehicle conditions:
Significantly cold or hot temperatures.
Sudden ...