Radio Code Woes

Those of you who have had code problems did you get an ERROR message at anytime? My daughter just purchased a 92 Acura Vigor. I just read an article that led me to believe if I put the wrong code in or the radio won't accept the code the display will give me an ERROR message.

1. I have verified I have the right code [I have it on the ash tray, pulled the radio out got the serial # and verified it is the right code with the dealer].
2. I disconnect the battery and reconnect it
3. I turn on the key then the radio
4. My radio display reads COdE [just like that in mixed case]
5. I put in the number and it beeps on the last digit and does nothing.
6. The word COdE stays on the display unchanged through it all.

I’ve gone through this process so may times I have lost count. The radio does beep on the last digit and it does lock me out on the third try. But nothing else happens.

Any thoughts at all? Tthis has become a real challenge for me. I feel like its got to be something obvious that I am missing. You suggest it I'll try it!

Thanks goodman