I had the same problem with my 2002 CR-V after replacing the alternator. The radio flashed the word "CODE". If you open the glove compartment there is a sticker (at least it was on mine) on the left side of the glove compartment door. The top number is the code. The bottom number is the serial number of the stereo. Enter the 5 or 6 digit code using the radio preset buttons. If that doesn't work call your local dealer & give them the serial (bottom number). they can find out the code for you.