I did replace the battery and the brake lamp switch. One thing I noted after reconnecting the battery - the sequence of the BAS/ESP malfunction coming on was the same as the latest occurrence of the malfunction. One difference though, this time I had to reset the Malfunction Indicator by cycling the steering (as the Owners Manual states). I measured the battery voltage during the start cycle and it now stays above 10.5. So we will see.

I know this is regarding an old post, Vince, but did replacing the battery and the brake lamp switch fix the problem???

Kidbyte

So far, yes. I haven't driven the car but 400-500 miles since that due to various reasons. I'm headed to DC this weekend with it. That should put another 450 or so miles on it.

Having the same problem
 

I have a 98 E430- and am having the same problem. When I turn on the car, all is fine. Then the moment I press on the brakes, the lights come on, along with the message that I have a defective bulb. The brake lights do not come on when I press the brakes.

My initial guess after reading the posts was that it was the brake light switch. I also had a bad rear light assembly. The parts I replaced to date are:

Stop light switch
All rear bulbs, including third brake light bulb
passenger side rear light assembly.

The brake lights still do not work, the BAS/ASR messages still come on, and I am running out of ideas. Should I just take this in to the dealer, or is there something easy I am missing?

Thanks.