1. Remove the front seat. (See FRONT SEAT REMOVAL/INSTALLATION.)
2. Remove the seat cushion trim.
3. While inspecting for continuity between the terminals A and B of the connector, use a dryer to warm the thermostat of the seat warmer unit on seat cushion.

4. When the indication on the ohmmeter is no continuity, turn off the dryer, then use a thermometer to measure the temperature of the thermostat.

5. Verify that the temperature is approximately 29 °C {84 °F}.
6. Verify that there is continuity between the terminals of seat warmer units connector using an ohmmeter when temperature drops to approximately 20 °C {68 °F}.


Seat warmer switch inspection
Body shellMazda 6 Service Manual: Control valve body removal
On-Vehicle Removal
Warning
Using compressed air can cause dirt and other particles to fly
out, causing injury to the eyes. Wear protective eyes whenever using
compressed air.
Caution
Clean the transaxle exterior throughout with a steam cleaner or
cleaning solvents before removal ...
Mazda 6 Service Manual: Dtc b1318
Caution
When attaching the tester lead to the ABS (ABS/TCS) HU/CM harness
connector, the SST (49 G066 001) must be used. (See ABS (ABS/TCS) HU/CM
INSPECTION.)
Diagnostic procedure
...