Owners have reported experiencing rough deceleration, inability to engage overdrive, and a check engine light with diagnostic trouble code P0770. Problems with the torque converter or deferred transmission maintenance can trigger this. Professional transmission diagnosis is recommended to address this issue to prevent unnecessary part replacement and expenditure.

The motor for the rear window sunshade in the Lexus LS400 is known to fail. When this occurs, the sunshade will not extend over the window, and a grinding noise is heard until the motor fails as well. Replacement of the sunshade assembly is necessary to correct this failure, however, removing the fuse for the sunshade will stop the motor from making the irritating grinding noise.