My Range Rover specs:
2.7 diesel, lockable differential

Problem:
After I changed the electrical hand brake box (upsite on rear diff), i started the engine.
After 1 or 2 minutes, it gave me the first error (the error that made me to change the electrical hand brake box) and it sounds like this : Hand Brake & Transmission system Error.

Do I have to reset the system or what could be the problem ?

P.S.: I didn't reset or syncronised the car with the new component after it's installation.

Thank you.