Can someone help me plz...I tried to turn on my car and it's telling me my battery is low and it won't start...so I decided to buy a new battery and it still won't start....what can it be ?Alternator ? I have a 2007 525i...it shows the battery message even with the new battery

 

It could be a faulty IBS (Intelligence Battery Sensor). Another reason could be a damaged main power cable. I know cases where the insulation has teared off from the spot where the cable goes through the car body frame to the underside of the car.

- Antti -

 

My battery got so low a few months ago that even with a jump start the car would not start. The dealership said if the battery gets too low, the car can stop communicating with the key fob chip, for security purposes...meaning they aren't talking to each other, hence the no start. I am guessing this is something the dealership would have to reset. Just one theory.

 

try jump-starting with a known good battery at the terminals under the hood and see if the car starts.

Alternator has nothing to do with STARTING the car. Battery, starter, ignition switch and the related cables - these are the things that need to be re-checked.

 

THIS.

If the IBS sensor is faulty you can put the key in and it seems like it will start but the IGN. won't start and pressing the 'start' button does nothing.

It's very simple to remove to check. Simply unplug it. If the car starts then the IBS sensor is dead.

 

might be the starter.. the starter went out at 54k on my car..i took the battery out and got it tested and the battery was fine.. so i towed it to the dealer and it was the starter.. so i did it myself because the warranty ended do the miles.. you could try getting a long thin pole and banging the starter and see if it starts... the starter is located under the 3rd or 4th intake runner