Battery or Alternator?

[705driller]

I was driving today and got a message saying charging malfunction. Then I also got a message saying battery draining while vehicle stopped. Eventually I lost my electric power steering, stereo, climate control, and limp mode. My car won’t start. Should I replace my alternator or battery?

[ChrisSilva]

More info. Year, model, engine. Any codes pulled? Preferably with a good bmw scanner and not a generic scanner.

[MarcoZandrini]

Get the battery charged. The car runs on the alternator, not the battery unless the alternator is bad.

[bmwdirtracer]

If you were driving, and got a message saying "charging malfunction", then something is wrong with your charging circuit. Trouble is, the charging is controlled bt the DME (engine computer) in your car, so diagnosis isn't necessarily as simple as throwing an alternator at it. Likely, that IS what you need, but since they run from $800-900, it would be a really good idea to have the car connected to ISTA (BMW's diag computer system) to verify, before buying an alternator. DON'T buy a cheap local rebuild alternator. A Bosch FACTORY remanufactured item is usually okay, if it comes in a Bosch box.

You will also undoubtedly need a battery; if yours is original, it has lasted WAY past the normal life on a modern BMW. The battery needs to be registered in the DME when replaced.

[328 Power 04]

I kind of wonder if you still have an accessory belt present on the engine?

[bmwdirtracer]

Wow, great thought, Abel!

[705driller]

The belt is still there it was the first thing I checked when I got the charging malfunction warning. Today I had to charge it then drive until the warnings came on and then I would recharge so I could get it to my driveway. I have a new alternator showing up Friday and will purchase a new battery as well. I will hook it up to my ista tomorrow after work and keep you posted.