MAN fault codes

i’ve looked these codes up.
edc:
03778 rail pressure leakage in overun conditions

03779 rail pressure leakage in quantity compensation.
ebs:
01056 trailer control module pressure control,maximum pressure.

the problem as you can see is that the codes mean little without knowing the operation of the system in question.you need to look at the code and then understand how the system works and change the part accordingly.
or as is often done just keep changing things and eventually it will go away. :open_mouth: