emc relay probs,,,,,,please help

[candywhitefudd]

hi new to this forum and really need help,,,, got a mk5 gti 2005 engine code axx just had full respray and when was put bk together batt had died. so they tried jump starting it with no joy. got a mechanic with diagnostic tool and came up with error code p0688 and p0685 auto data say emc power relay fault. now ive called around local dealers and the are compleatly useless aint got a clue. also rear brake lights wont go out........pls help need the relay and need to know where it is ?