AchtungE60

I know nothing about SMG but I can chime in on several BMW issues I've had in the past in reference to the ZF auto tran going into limp mode...One issue turned out to be a bad relay up front by the DME. Another turned out to be a bad Mass air flow sensor. Another turned out to be incorrect fluid and another needed half a liter of fluid. One turned out to be that the MAFS was not getting enough power and would send out some BS pulses to the DME to throw tranny into 'limp mode' (fail safe) where it was stuck in 3rd or 4th gear constantly so she could "limp home" lol....and when try to go in reverse it would kick in gear and back in neutral constantly (this was with incorrect fluid)

I found out about the relay issue and MASF issues after complete tear down and rebuild of one tranny.....which was not the cause but cost a nice chunk of change to learn. The problem with these cars is that the Germans have a completely electronic driven car and have shit electronics. Is there a mechatronic sleeve on that SMG?

This could be from many issues so I would tackle them all with the least expensive first. It'll take time but what else do you have? Just be patient and try to start from electrical on....Make sure everything checks out...battery, alternator, MAFS, relays, fuses, etc. Obviously you'll know when a fuse is bad. A relay is harder because you can see what's going on insides...a battery swap will let you know if it's the beginning of the electrical current. good luck

AchtungE60

+1

Temporarily swap it out, as ur current battery could read ok according to standards but not to your E60

AchtungE60

Well looks like you already came out of pocket on this. Hopefully that's what needed to be done and you weren't "had" it's a dirty game based off the "buddy system"