1. Disconnect the negative battery cable..
2. Remove the center speaker grille..
3. Remove the front center speaker..
4. Verify that the resistance between the front center speaker terminals is as indicated in the table.

If not as indicated in the table, replace the front center speaker.

Entertainment System
Front Center Speaker Removal/InstallationDifferential [C66 M R]
Purpose, Function
The differential absorbs the rotation speed of the inside and outside wheel
of a wheel set when the vehicle is cornering.
Construction
Operation
Driving in a straight line
Cornering
...
DSC HU/CM Removal/Installation
WARNING:
If the DSC HU/CM configuration is not completed, it could result in an unexpected
accident due to the DSC being inoperative. If the DSC HU/CM is replaced, always
use the automatic configuration function so that the DSC operation conditions
are correct.
If the DSC re ...
Headliner
Purpose/Function
The headliner is equipped with a shock absorbing pad for driver's head protection
during a collision.
Construction
The front and rear side of the headliner is equipped with a shock absorbing
pad with a plastic rib-pad structure.
...