Help in diagnosing xenon range control required

[Ronin]

So I've had errors 0774 and 0776 since purchasing the car, so I tried to fix it by following this http://forum.a8parts.co.uk/showthread.php?t=12058 thread to renew the harnesses which I've succesfully done but after resetting the errors and going for a drive, the errors immediately come back.

Should I replace the sensors next or maybe the headlight aim control module? Is there a way to further test the output of each module? I'm really not sure how to tackle this...