Hey, my friend,
I also experienced the same problem in my M6, but mine isn't Bose system. There is a sequence of pressing some knobs that had reset my system. You can give it a try. Turn the key to ACC position. Press the next buttons in the row 6(>>) , AM(frequency) , DISP/AUTO-M , and SEEK. Four dashes - - - - should appear on screen. Insert the code 4 9 8 9 as you inserted the safety code. Press together and hold the buttons, DISP/AUTO-M and 6(>>),until "good" appear. Good Luck.