high level brake light

2003 skoda octavia 1.9 tdi , high level brake light stopped working,took it off wired it to battery its ok works,wired it to low level brake wire it works,but still getting warning light and annoying beep and warning message,checked wiring under cd holder in left hand side of boot the connector wich i think is the one that shoots off to high level brake light dont seem to have power,so i guess must be some where else if i piggy back the wire to low level do i have to take it to garage and have the code delated so it stops the beeping and warning or am i on the wrong track.thanks for any help given,boy do i need some.