If the battery on your Honda dies and the car's audio system is equipped with an antitheft device, your radio will not work properly after the battery gets recharged. The antitheft device will lock you out unless you can provide the radio's unique identifying code. Finding this code will be much easier if you have managed to hold on to an identification card listing the radio code. Without the card, finding the radio code and unlocking the audio system will be more difficult.
Make sure your Honda radio requires a code. If it does, once power has been restored to your vehicle, your Honda's audio system will flash a message indicating that you must punch in a special code to disable the antitheft device. The message may be the word "Code." The antitheft device is meant to thwart criminals from operating an audio system they have stolen from a vehicle.
Find the four-digit or five-digit code number that will unlock your Honda's audio system. The code number was printed on a document you should have received along with the owner's manual when you bought your Honda. The document could be small, about the size of a credit card. It also lists the audio system's serial number.
If you cannot locate the card, you will need to track down the audio system's serial number so you can get the radio code. With some newer Hondas, you can find the serial number electronically from the radio. The owner's manual will tell you how to do it. Once you have the serial number, you can go to Honda's online Radio & Navigation System micro-site to obtain the proper radio code. You will need to provide other information, such as the car's vehicle identification number, to show you own the vehicle.
Getting the serial number for Honda models from 2003 or earlier will require you to seek help from a Honda dealer. Be prepared to prove that you own the vehicle. The dealer also will be able to trace the radio's code number.
Use the preset buttons on the radio to punch in the appropriate digits after you locate the radio's code number. That should unlock the radio and make the entire audio system usable again.
If you accidentally hit a wrong key once you know the code, you will not be able to reverse the error. Instead, finish entering the appropriate number of digits. Then try again, starting from scratch.
Repeatedly punching in the wrong code number within a short period of time will cause the audio system to lock you out until you leave the system on and undisturbed for one hour.