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: Driving Tips
WARNING
Do not let the vehicle move in a direction opposite to the direction selected
by the selector lever: Do not let the vehicle move backward with the selector
lever in a forward position, or do not let the vehicle move forward with the selector
lever in the reverse position. Otherwise, t ...
Mazda 6 Service Manual: Compression pressure
COMPRESSION INSPECTION
Warning
Hot engines and oil can cause severe burns. Be careful not to burn
yourself during removal/installation of each component.
1. Verify that the battery is fully charged.
Recharge it if necessary. (See BATTERY INSPECTION.)
2. Warm up the engine to the no ...