NB F/L MX-5's had an audio unit fitted from new that was uncoded. A unit that has had a security code entred will flash the "Disc In" light when the ignition is switched off.
A security code can have been input either by the Dealer or customer. Often the code does not get passed on to a 2nd owner so many owners find that their unit displays ERR after trying to input an incorrect code after battery disconection.
Mazda dealers have a master code that will unlock units displaying “ERR” where the code has been entred incorrectly.
Due to the sensitive nature of radio codes, requests for the unlock codes for audio units will be deleted from this forum.