Just had a look at the audio manual
As you have a code that includes 7, 8 or 9 you can't have a Generation 2 unit as there aren't buttons numbered 7, 8 or 9
thus once the "code" legend appears in the display try
using preset button1 press it till a 1 appears in the code, then
using preset button 2 press it repeatedly till an 8 appears then
using prest button 3 9 then
4 4 appears
and then press prest button 5 to confirm
Don't keep trying it too often or you may get problems later