Do you have the remote? If so, try this if you haven't so already:
IN YOUR RADIO: DISPLAY WILL ASK FOR CODE AND CODE ---- APPEARS ON, SO, HOLD .DISP AND PRESS VOL UP AT LEAST 3 SECONDS. THE "----" WILL DISSAPREAR. NOW TAKE YOUR REMOTE AND DIGIT "KCAR" WITH THE NUMBER PAD.
PRESS "5", "5", >>| (NEXT TRACK) YOU GOT A "K"
PRESS "2", "2","2" >>| (NEXT TRACK) YOU GOT A "C"
PRESS "2", >>| (NEXT TRACK) YOU GOT A "A"
PRESS "7", "7", YOU GOT A "R"
PRESS >>| (NEXT TRACK)
IF DISPLAY SHOWS "APPROVED" YOU'RE DONE
It will Spell out KCAR when Done....