Honda 2000 Accord Sedan Online Reference Owner's Manual page 235

On EX, EX-V6 and Canadian SE
models
If your car's battery is disconnected
or goes dead, the audio system will
disable itself. The next time you turn
on the radio you will see "Code" in
the frequency display. Use the
Preset buttons to enter the five-digit
code (see page 152 ).
NOTICE
Charging the battery with the cables
connected can seriously damage your
car's electronic controls. Detach the
battery cables before connecting the
battery to a charger.
Battery
Maintenance