Helo π
First check if you have Power to brake switch, and if you have , then check if you have out of it.
you have a stoplamp relay in underhood fuseblock.
You have only one ground point to ecu, G103, as you have Picture off.
That goes to pin 1 and 40 on C-1 Blue Connector, and to pin 1 and 40 On C-2 Red Connector.