I'm just about at the end of the rope with my 400E. I've had the codes pulled and was hoping that the Brake Light Switch (which came up along with EA) was the solution to my chronic ASR/LIMP Home problems (occurs with cold starts every morning).
Along with the Brake Switch, I've changed the wiring harness several months ago, checked the linkage(fine),and cleaned the wheel sensors. It would seem that replacing the ETA is the last and obvious alternative, or is it?
Please if anyone has any further suggestions or, has a source for a rebuilt ETA (are there any?) please let me know. I can't really afford the $1100 part and 4 hours of tech time.

Did the codes get cleared after replacing the brake switch? I don't know the actual procedure, but I understand from other threads on this site that there are at least 2 separate computers which need to be cleared of codes after fixing something in the throttle actuator system for everything to communicate correctly.

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Steve
'93 400E

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.

Most of theASR failures seem to be related to the electronic throttle actuator. Also the accelerator (throttle) position switch sometimes gets funky and will trigger the limp in mode. (If the engine control computer senses the electronic throttle opens, but the accelerator position switch has not closed to indicate movement of the accelerator pedal--it goes TILT and goes into the limp home mode.

If the throttle plate position sensor reading does not agree with what the computer tells it to be--again it goes TILT.

To make it 'fool proof', the ETA has yet another throttle plate position sensor called a 'reference', and its resistance changes opposite to that of the first position sensor, and if the two 'position sensors' do not agree ---TILT.

If the values read on the position sensors do not move in a smooth and unbroken fashion--TILT again.

It won't run-away for sure. Now--if the damn things would just WORK.

Thanks 'Kebowers' for your reply. Are you suggesting that maybe by replacing the accelerator throttle position switch and "reference" sensor that I might avoid buying a new ETA? Do you happen to know the part numbers for my M124 (92 400E). Your advice is appreciated.

Has anyone had ASR problems that were caused by a vacuum leak?My 400E surges while idling along with ASR/LIMP HOME problems. Please anyone with similar issues that have had successful outcomes without completely replacing the ETA kindly comment.