Code Entry as Follows:

Switch ON the Ignition (No need to start car)
Switch Radio On - Display Shows
" SAFE " and then shows " 1000 "
(This may take up to 10 Seconds - be patient)
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 RH Tuning Button " >> " To Enter