Bass-Box Inspection

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Remove the trunk board. (See TRUNK BOARD REMOVAL/INSTALLATION .)
Disconnect the short-cord connector. (See BASS-BOX REMOVAL/INSTALLATION .)
Verify the resistance between bass-box terminals.

Fig 1: Checking Resistance Between Bass-Box Terminals
Courtesy of MAZDA MOTORS CORP.
- If not within the specification, replace the bass-box.
Fig 2: Bass-Box Terminals Chart
Courtesy of MAZDA MOTORS CORP.