I don't believe feature 18 will unlock a directional lock. It may help a engine that refuses to leave neutral. If a PS-1 is lock in a directional state there are no dings on start up. Just sounds, To unlock you have to hold down the whistle button until you hear a whistle blast and immediately cut power... It's been so long since I've done it you may want to dig out the manual for a directional lock,( neutral/ forward/ reverse.)
Refusing to leave neutral and locked in neutral are 2 different things..