My 2001 bmw 330i alarm key battery is dying.

Hello again Sondra
Simon Atkinson and I both answered your query and we both mention parasitic battery drain. None of us mentioned a 'battery reset' and as far as I am concerned, I have never heard of anything like that. A battery is an inert box of lead and acid that holds a charge that you put into it. The engine control module monitors it and BMW being who they are DO in fact have a BATTERY RESET procedure!!

https://www.google.com/search?q=2006+bmw+330i+battery+reset


Also, if you disconnect the battery for even a short length of time, you will need to reset the security system and immobilizer.

https://www.google.com/search?q=2006+bmw+330i+reset+security+system

..

Check the fuse. If fuses are good, check the battery in the remote. If that is good, try unhooking the negative battery cable for 10 seconds and reconnecting it.

change your central locking relay.

More than likely it is the alternator not putting out enough to run the car.

This could come from a variety of places... in no particular order... the "new" CPS is bad (get another one)... The battery is weak or has low voltage (replace battery)... The DME may need an update / DIS CD 30.0 or higher... dealer or good Independent shop can do this) last one to look at is the fuel filter (replace)

it maight be your key or your dme or immobilizer control unit.

I'm having the same problem have you fixed yours?

In Rear RH Side Of Luggage Compartment. lift up floor covering

TRY CHECKING THE ALARM BOX, I HAVE A 2001 525IT WAGON AND MY ALARM BOX IS LOCATED IN THE RIGHT REAR BY THE BATTERY, TRY DISCONNECTING IT AND OPEN IT UP SOMETIMES CONDENSATION GETS IN THERE AND CAUSES THAT ISSUE.

HOPE THAT HELPS

i have seen on more than one occasion the new ALT going bad after about a week or so you may want to check your charging system again and see if you can warr out the alt if it is bad