It certainly is suppose to. But obviously, many of these system do not work as designed. And lazy technicians have become slaves to what ever the computer readout tells them.

Case in point. On the way to the dealer I got a red message on the i-drive screen which said something to the effect of "Major Electrical System failure. Continued operation not possible. Pull to side of road and contact service center." So I began to pull to the side of the road and within 10 seconds the message disappeared. A check of the "Check Control" section of the i-drive said, "All System OK." Had a check engine light, but as it was yellow, not red, I continued to the dealer and left the vehicle. Call later in the day had the technician saying that there was nothing stored in the memory about an electrical system failure.

So no, I do not believe the BMW computer is either perfect, or that it has a perfect memory.

And, I might add, if a lengthy parasitic drain test to look for modules not going to sleep is so unnecessary, since the power management computer notes everything, why does BMW have such a test procedure in their documentation?

Think.