Hello folks,

My 11/08 manufactured E60 LCI has been demonstrating high battery drain over the past couple of weeks. I have checked that there are no electronics connected to the car overnight but the issue has persisted. As the next step I wanted to check whether the IBS cable is faulty and wanted to see if the battery drain changes with it disconnected.

The process is straightforward to disconnect the blue connector and monitor battery voltage to check whether the IBS cable is faulty or whether there are other modules not going to sleep. I thought this should be any easy check to complete before I perform a more time consuming parasitic drain test on all modules using the rear and front fuse panels. However, I came to know that there are several versions of the IBS cable and the most common one seen or documented on the forums or in YT videos is from the pre-LCI version where the IBS cable has three outlets from the -ve battery terminal, first goes to the ground, the second is connected to the +ve terminal for power and the third terminates in a blue connector that communicates with the DME.

When I opened up the battery side boot panel, I noticed two things:

1. Mine being an LCI is different, the third outlet does not terminate in a connector, it instead is integrated to a larger wire harness routed towards the front of the car.
   
   (Image 1 - Shows the third outlet consisting of a red and grey wire going straight to a larger wire harness with no connection in between)
2. There was a loose red wire coming from a connector lead plate
   
   (Image 2 - Shows the loose red wire with a bare lead)
   
   (Image 3 - Showing another view angle of the source of the red wire)

My questions to this forum are:

• To test for a faulty IBS, do I just remove the connection at the -ve battery terminal?
• Does anyone know where the red wire is supposed to be connected to?

Thanks in advance!

 

What BMW-specific codes did you read? Please refer to Is My Battery Bad? - 5Series.net - Forums.

 

Here is my E60 2010 LCI configuration. The "red" wire that you are talking about is actually "brown" and it looks like it is going into the taillight assembly as a ground.

 

Hi there, the code was 2DED. Will go through the reference thread as well.
For reference, my battery voltage seems to start around ~12.5V and loses charge day by day. However, with the ignition on, the voltage is above 14.2V.
I also don't think my battery is going out, it was replaced around 4 years ago from the original battery that the car came from the factory.
I just wanted to do simple checks before getting into more involved voltage testing across each fuse.

Thanks