To Remove "Dial 9" Feature:

Press Program

Enter 19

Press Enter

Press "SEL" key till it says "Idle Line"

Press Enter

Lift and Lower Handset to exit programming mode


To Add "Dial 9" Feature:

Press Program

Enter 19

Press Enter

Press "SEL" key till it says "Intercom"

Press Enter

Lift and Lower Handset to exit programming mode