[M3jamaica]

I can get a 2011 x6m at a very cheap price. Owner fed up as he cant figure out the problem. Here what he told me, please let me know if this sound familiar to you and have any idea what the problem could be......
Over 1 year ago he got a CEL, out of warranty he brought it to a bmw dealer and they changed coils,plugs,injectors and injectors module, he spent a small fortune and it took a long time due to them sourcing the parts. Got the car back and after 2 days he was back in safe mode.He brought it back and they seem not to be able to find the problem so as he got upset he took his car back and put it for sale.........
Im tempted because of the price, and its only 55000km. Any idea what the problem could be? One of those mechanics told him that he needs a different module, that probably they put in a wrong one......