Mercedes-Benz CLS-Class 2008 Owners Manual - Manual (Page 188)

187
Controls in detail
Good visibility
! If the rear window defroster switches off too
soon and the indicator lamp starts flashing, this
means that too many electrical consumers are
operating simultaneously and there is insuffi-
cient voltage in the battery. The system re-
sponds automatically by deactivating the rear
window defroster.
As soon as the battery has sufficient voltage, the
rear window defroster automatically turns itself
back on.