What does the 'SD' error code mean and what should I do?

The 'SD' code means a Suds Routine has been automatically triggered due to excessive suds being detected. The routine removes extra suds and ensures proper rinsing of garments; 'SD' is displayed during rinsing and at the end of the cycle to inform you the routine was activated. To prevent this from recurring, use only HE (High Efficiency) detergents. (Page 22)