Move the float to the topmost and bottommost positions, and verify that the resistance between terminals A and B of the unit and the position of the float are as indicated in the figure.

Pid/data monitor and record procedure
Oil pressure switch inspectionMazda 6 Service Manual: Cargo compartment light switch inspection
1. Remove the liftgate lower trim. (See LIFTGATE LOWER TRIM
REMOVAL/INSTALLATION)
2. Disconnect the cargo compartment light switch connector.
3. Inspect for continuity between the cargo compartment light switch
terminals using an ohmmeter.
If not as specified, replace the liftgate lock.
...
Mazda 6 Service Manual: How to use AUX mode
1. Select the icon on the home
screen to display the Entertainment screen.
2. Select to switch to the AUX
mode. The following icons are displayed in the lower part of the center display.
NOTE
If a device is not connected to the auxiliary jack, the mode does not
switch to the AUX mod ...