Mazda factory-installed stereos come equipped with an electronic antitheft feature. The head unit requires a four-digit code when the stereo is installed or reconnected with the battery. The code for your Mazda's stereo is found in the dealer-provided factory owner's manual. If you do not have the manual but remember or have recorded the code elsewhere, you can enter the code to unlock the antitheft mode. Be careful--three erroneous entries will require that you to take your vehicle to the dealership to have the code reset.
Press the "SCAN" and "AUTO" buttons located on the right side of the stereo's face simultaneously until four dashes (or bars) appear on the display.
Press the "1" button among the preset buttons located below the display as many times as are necessary to input the first number in the antitheft code. For example, if the first number is "5," press the "1" five times.
Press the "2" the number of times needed to indicate the value of the second number in the code. For the number "3," press the "2" button three times.
Continue with preset buttons "3" and "4" for the third and fourth digits until all four digits for the code have been entered.
Press and hold the "SCAN" and "AUTO" buttons for at least two seconds. The word "CODE" will appear in the display to signify that the unit has accepted the code and operation of the stereo is possible. If "Err" appears in the display, begin the process over.