BMW Repair: 1993 bmw 740il ecm, 1993 bmw 740il, bmw 740il

Question
hi i am a mechanic 93 bmw came in not runing i took the easy way and checked fuel replaced fuel pump and relay and filters car has 230000 mi car ran about 3 hrs.and then shut down then i checked main and fuel relay usesing alldata tests i have no ground to main relay from ecm alldata has no test for ecm do you have any idea how i can check ecm it coasts 700 ot 1000 dollars?  

Answer
most likely the ecm is bad. because the ecm supplies the ground to the main relay and you have no ground to it now, the ecm is the likely culprit. there is really no way to check the ecm itself, you need to perform various tests to rule out other problems. if all tests prove ok, then you know the ecm is bad. basically you would want to check all inputs and outputs but you would need a breakout box. check the connections on the ecm, are they bent, pushed in, corroded? what is the physical condition of the unit? does it look like it may have gotten wet?