Heater, Defrost 601F SVCE (501F, 601F, 601F-2)
  501F    Use Starting with #1004775, and from
          #M/P960170 to #M/P960319, and from
          #M/P996400 to M/P996574.
          Prior to #M/P960170, and from #M/P960319
          to #M/P996400, and from M/P996574 to
          #M/P1004775 see 7016022.
  601F    Use Regardless of Serial Number.
  601F-2  Use Regardless of Serial Number.