Code Entry as Follows:

Switch On Ignition (No Need To Start Engine)
Turn Off Stereo
Press & Hold Preset " AS " and
Switch Radio On - Display Shows
" SAFE " And Then Shows " 10 - - - - "
Press preset " 1 " repeatedly for 1st Digit
Press preset " 2 " repeatedly for 2nd Digit
Press preset " 3 " repeatedly for 3rd Digit
Press preset " 4 " repeatedly for 4th Digit
If the correct code number is now shown
Press & Hold Preset " AS " Until the Unit Beeps