Just picked up a 2011 R60 All4 S about 1 1/2 months ago. Yesterday was driving on the interstate and the battery light came on the dash. I thought it was odd, but OK. Got off the interstate to surface roads to my destination and almost all the warning lights came on--ABS, Brake pad sensor, battery, steering--one by one. I even had diminished power and lost power steering. I pulled off and put it in park and called my wife to get her prepared to come pick me up or call AAA. Anyway, it would not go back in drive and the gear with ! light was on the dash. I shut the car off and waited and it started back and I could put it in gear. I drove to my destination, then had to go home..drove surface streets since I was afraid of it dying on the interstate...got home safely.

I did stop at autozone on the way home and had them put a OBD reader on it and it came up with the following DTC's:
ABS
Power Train

Secondary DTC's
5E30 Control Unit internal: System voltage excessive Low
5E31 Control Unit internal: System voltage low
5015 battery voltage

Long story short. I thought it was probably the alternator, but I have done some digging and a dying battery may do the same? Someone also mentioned perhaps a bad alternator cable or fuse? I didn't need to drive today so I just went out expecting a dead battery, but it started fine and has ZERO error messages.

I just moved here and can't find my volt meter (it's still in a box somewhere!) I'll pick up a new one.

My plan is too check the voltage while it's running to see if it's charging. If it is should I "assume" the battery is dying and won't hold a charge or something else? All thoughts and comments are welcome. Thanks in advance.

 

If that is the original battery I would replace it.

I just put a battery in my 2018 F56 after five service years. The car was profoundly unhappy.

Get the VOM out, but a battery is not going to hurt, and if done the alternator (more expensive) would be the remaining culprit.

It seems battery life of 4-6 years is common in these cars.

Cheers,

Charlie

 

Thanks for the reply Charlie. I just looked up the maintenance records from the previous owner, thankfully he was meticulous and gave me all his records. He had the battery replaced in August of 2018, so it is a little over 4 years old...so I will replace it and go from there. Should I go OEM battery route or other? I usually put Interstate in my vehicles...Thanks

 

Dunno on the 2nd Gen, I went OEM on my 3rd Gen as it seemed safest.

I used to run a tiny light battery in my R53 but that was then,,,

Cheers,

Charlie

 

I determined that I don't have IBS so I don't have to code a battery...since I live in a very cold climate, I will put an AGM battery in it. Hopefully that is it...

When I cranked it this morning it started fine and had no warning lights....someone suggested it could be a bad or loose cable from on the battery, alternator or to the PCM. I will check those out as well.