Steve, thanks for your comment. Yes, the tech did reset the codes afterwards and,of course, the car drove beautifully until the next moring. Now, the ASR/LIMP Mode comes on ans stays on even when I recycle the ignition. I wonder how many otherwsie good driving M124s are junked when this problem comes up late in the car's life. I see ebay has several clean 300e&400es selling for about what it would cost for mine to be repaired. Thanks again for the comments.