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: Electrical troubleshooting tools
Jumper wire
A jumper wire is used to create a temporary circuit. Connect the jumper
wire between the terminals of a circuit to bypass a switch.
Caution
Do not connect a jumper wire from the power source line to a body
ground. This may cause burning or other damage to wiring harnesse ...
Mazda 6 Service Manual: Oil cooler
LF, L3
1. Remove the under cover.
2. Drain the engine coolant. (See ENGINE COOLANT REPLACEMENT.)
3. Remove the oil filter cover, and drain the engine oil into a container.
(See OIL FILTER REPLACEMENT.)
4. Remove in the order indicated in the table.
5. Use a clean rag to wipe off the m ...