ASR Failure on acceleration
 

I have a 1993 300SE (W140) that the ASR causes the "limp home mode" to engage periodically. It is pretty consistant that it only happens on acceleration onto the freeway and typically under load (other passengers). I have had the engine wire harness replaced along with the stop switch. It has been in the shop many times for this without resolution. The codes appear to be a CAN bus error according to the shop. Has anyone else solved a similiar situation?

Check for equal rear tire pressure...

MAF?
only a guess because of the under load?

I like Arthur's idea because when I bought my '94 E320 the dealer had Michelin MXVPlus 3 on the back and MXVplus 4 on the front and because they are slightly different WRT outer diameter or something like that, the speed senors at the wheels were going crazy causing things like you describe.

Could be the . . .
 

internal wiring in the ETA (Electronic Throttle Actuator). Probably has deteriorated and causing intermittent problems such as you describe. Or the "reference potentiometer" has some worn spots.

Check out my page, MENU#24 for DTCs including CAN bus problems. That's one of the main symptoms of a bad ETA.

Also check out the thread on the ETA on an SL. There are some pictures showing what happens to the internal ETA wiring. Note that it is referred to as an "EA" but it's the ETA or TA. http://www.peachparts.com/shopforum/showthread.php?t=112493

Thanks for all of your helpful information. The problem has (temporarily?) gone after replacing the voltage regulator. The regulator was in real bad shape and posts were worn done. Hope that was it as the ETA is more than I want to deal with! Will let you all know what happens afet I get more miles on it.