E-01 Fault in changer Replace changer
E-02 Disc allready in mechanism Eject magazine, insert empty magazine, eject disc.
E-03,04,05.
Fault in changer If code disappears within a few seconds, changer is ok, otherwise, replace unit
E-06, E--- Fault in changer Press magazine eject and remove cassette. Check for new fault code. Reinsert cassette. If cassette cannot be removed, replace unit.
E-07 Cassette jammed in CD changer. Try to eject magazine. If unsuccessful, try emergency "credit card" method. If magazine remains jammed, replace unit.
E-30 Temperature too high. Changer will operate again at lower temperature.
---- No cassette in changer Insert cassette.
2--- No disc in compartment 2 in cassette Insert disc.
This info is from a 700/900 TSB dated early 90's. Should also apply to the factory changer used in the 850.