I have 2000 528i (90,000 miles) and I had noticed both ASC and ABS lights are on. Recently battery went dead and was trying to jump start. After that check engine light came on along with ASC and ABS lights.
Took it to my mechanic, replaced battery, run full scan and did not find any faults/errors but both engine check and ASC/ABS lights are still coming on when engine is running.
One thing I have noticed though is when I start the car in the morning and leave it idling, while engine is still cold, ASC and ABS lights goes away. Keep the engine idling for about 5 minutes and then I have noticed one in a while rpm goes down and goes back up again and continue doing the same every once in while(little less then a minute). At one time engine after idling like that for about 10 minutes stalled. When I started again both ASC and ABS lights came on again and did engine kept running smooth while idling, no change in rpms.
Not sure if this behavior can be explained because engine is cold and computer is not fully functioning at first,, or something else.
Any ideas suggestions are greatly appreciated.