Many models of the Nissan Micra are equipped with an antitheft system connected to the factory-installed radio. When the radio is disconnected from the electrical source by removing it from the car or unhooking the battery, the antitheft system locks the radio. The radio can only be used again once the security code is entered. The code came with the car when it was new. If you no longer have the unlock code, contact a Nissan dealer to have it looked up.
Turn the ignition on without starting the engine.
Press the power button on the radio to turn it on.
Enter the four-digit code using the radio preset buttons.
Press the volume-up button to submit the code. The display will indicate "CODE OK" if the code was accepted. The radio is ready to use.
If the code is entered incorrectly, you must wait 10 minutes with the radio turned on before trying again.