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: Dynamometer
When inspecting and servicing the power train on the dynamometer or
speed meter tester, pay attention to the following:
- Place a fan, preferably a vehicle-speed proportional type, in front
of the vehicle.
- Make sure the vehicle is in a facility with an exhaust gas
ventilation ...
Mazda 6 Service Manual: Schedule 1
U.S.A. and Puerto Rico residents - Engine oil flexible maintenance interval
Use when the maintenance monitor for “Oil Change” is set to “Flexible”. For
details, see maintenance monitor.
Chart symbols:
I: Inspect: Inspect and clean, repair, adjust, fill up, or replace if necessary.
T: ...