Yesterday i got into my Disco I and everything was fine in the morning. After i came back from lunch i noticed a hum coming from under my hood. I opened her up and listened and the hum is coming from the ABS unit on the driver side. It is humming in 2 different pitches a high pitch and a low pitch. The humming alternates between the 2 different pitched. My brakes appear to be working fine for me. There is no softness to the brake petal. When the car is off and the humming goes on it will drain my battery.

Any ideas out there. Please help

 

Normal, it should turn off after a while.

 

Might want to pull the fuse, for now, save killing your battery and burning up your ABS. After pulling the fuse, verify the brakes are working OK and then find a mechanic that is familiar with this issue.

 

There was a TSB on this, take it to your dealer and talk to them, a simple reprogramming of ABS computer is all that is needed.
Like Mike said it will run your battery dead.
it is supposed to stop after 5 min or so.