1999 E300 TD BAS control module?

Why is it you are replacing it? Is it because you see that warning sign when you just started up the car first thing in the morning? And that sometime it doesn't show up?

I'd suggest you look over your service record and see when you replaced your main battery.... The reason I asked is that my folk's 01 E320 did the same thing... will always show up first thing in morning and randomly all other time. We had the dealer check and nothing is wrong with it. On the second time, they did an extensive test and found the main battery is bad... that causes that malfunction error.

Voltage is very important for computer... it is how they determine if something is wrong... so weak battery will show lower sensor reading and computer may thing something is bad.

The car starts with zero problem but we get lots of errors... ABS, BAS and finally SRS... geez... All fixed with a new battery.