Ok I have a question maybe you can help me with I was driving my car the AC fan stopped blowing and then it said transmission malfunction towed it back to my house then the battery was dead so i charged it I drove to Baytown about 18 miles then to nrg stadium about 35 miles then home again the next morning battery was dead jumped it it's then before I left my drive way it said transmission malfunction code p1890 and I heard a snap and it wasn't my Serpentine belt any ideas?

 

An old battery manifests a slew of different codes and errors. The first thing I would do is remove it and have it tested at an auto parts store. If you need a new one, Auto Zone and Advanced have very good prices on BMW batteries. There are a number of threads here on what you need and what to do. Install it and get it registered. A BMW indy should be able to do it for under $50. Have them clear the codes and see if it clears up the problems. If not, you have other issues.

 

Sounds like your alternator is dead. it's running off only the battery which is why it keeps dying.


No idea on the "snap" noise - I'd figure out the dying issue first and see if you still have others afterward.

 

Its the hedgehog sensor.

Check and replace this.

 

This is not working correctly, therefore when you switch the car off the heater fan stays on, draining the battery.