Just got a 1991 miata. excellent condition, runs super BUT, the radio flashes COD 8. I tried the reset procedure, but COD 8 continues to flash. The local dealer say's they have no manuals to figure out what COD 8 means, but it may indicate an internal fault . Any idea's short of a new radio ??

 

Does the display read COD 8 or COD e ?? COD e means that the anit-theft function has been activated and audio unit is waiting for you to input the four digit code to reactivate the radio. Since the Miata is new to you, you probably do not know the code that was originally input by the previous owner. In order to clear this unknown code you first need to "lock" the unit up by entering three incorrect codes.
Codes are entered by the following.
With COD e displayed, push the REW and FF simultaneously for approx 2 seconds. Display should change to four dashes ( - - - - ). Release the buttons at this point. Now use the radio station preset buttons 1-4 to enter the digits. First digit is entered with preset #1, second digit with preset #2 and so on. First press of preset #1 will change first digit to 0, second press will change to 1, third press to 3, etc. Justperformthis code entering procedurethreetimes and display should change to Err and will not allow any more code input. Radio is now locked and can now be unlocked. Let me know if this procdure works and we will then work on unlocking.

 

I'll give it a try right now !!!!

 

Okay, it was COD e, I thought the bottom rt of the 8 was burned out. I followed the procedure you suggested and the display now reads "err". Worked just as you said it would !!! Ready to unlock !!

 

Good job sjcat. One more set of button pushes and radio should be back in business.
Start with the key on, Err displayed on radio.
Press and release the following fourbuttons in this order.

Radio preset #1
STOP/EJECT
AM/FM
CLOCK

Display should now go back to the four dashes ( - - - - )
Using the same preset buttons #1-#4 enter the code 4989
Once that code number is entered, push and hold the REW and FF buttons at the same time and hold them until the display shows 777. Release buttons and display should now be in clock mode with an unlocked radio.

 

Incredible - you have saved me a hugh amount of frustration and expense. You have done what the local dealers could not!!!! The procedure worked as advertised, thank you so much!! My curiosity is up - has Mazda improved this system in the last 16 years ??

 

Glad to hear you have tunes in time for the weekend.
Mazda has improved the audio theft system since by completly discontinuing its use since the late 90's.

 

I would LOVE to try this to unlock my err however I do not have a CLOCK button. Anyone... help??!!

 

When it rains, it pours, macbabe. This is the second radio reset code request today.
Try this thread: https://www.mazdaforum.com/forum/general-tech-6/mazda-radio-code-reset-15083/