I broke the old radio display and it won't play cassettes anyway, so I bought replacement OEM model from online retailer. Installed, and it says "LOCKED" (not "LOC").
I have the procedure to get the code out of the radio :
"Press and hold presets 2 and 3 for about 5 to 10 seconds until you
get 3 digits on your display" but nothing happens - no change in display, nothing.
x2 as above.
From what I understand in the future, the radio can also be programmed with a no code setting, by dealer as well, to prevent lock downs from battery removal etc.
I use an OBDII power plug (power saver) before removal of battery / disconnecting power.
Seems to hold radio settings and no lock downs... Thank Goodness!