1. Inspect for resistance between the tweeter terminals using an ohmmeter.
2. To verify that the tweeter outputs sound, apply voltage to the tweeter and release using a 1.5-V battery.
Mazda 6 Service Manual: Thermostat
THERMOSTAT REMOVAL/INSTALLATION
1. Remove the plug hole plate.
2. Disconnect the negative battery cable.
3. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS.)
4. Remove the drive belt. (See DRIVE BELT REPLACEMENT.)
5. Remove the washer tank.
6. Remove the P/S oil pump.
Note
...
Mazda 6 Service Manual: Instrument cluster input/output check mode
Note
In this mode, it is possible to check the items in the following
chart.
Diagnostic Trouble Code Chart
Note
Diagnostic trouble codes which are not listed may be indicated,
but they cannot be inspected.
The diagnostic trouble codes are displayed in numerical order.
(While ...