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: Oil leakage inspection
Use either of the following procedures to identify the type of oil that
is leaking:
Using UV Light (Black Light)
1. Remove on the engine or transaxle.
Note
Referring to the fluorescent dye instruction manual, mix the
specified amount of dye into the engine oil or ATF (or transaxle ...
Mazda 6 Service Manual: Clutch fluid replacement
Caution
Be careful not to spill clutch fluid on a painted surface. If this
should happen, wash it off immediately.
Note
Do not mix different brands of clutch fluid.
Do not reuse the clutch fluid that was drained out.
1. Remove the under cover.
2. Draw the fluid from the reservoir ...