Did you ever find a resolution? My ASR light is INTERMITTENT with a resulting limp-mode and high-RPM upshifts. Over the past 30k, PO's shop replaced "idle contact switch" and JUST replaced "throttle body actuator." What exact parts are these? If these have been replaced, before I take it to the next shop for a proper diagnosis, what should I expect them to tell me?

I want to get a first-time fix on this thing if possible, and I will be waiting a few days for a shop manual. This thing is quite a bit more complex than my old c230, and I don't want to get into throwing parts at it based on codes, when there may be a small contact or switch issue.

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former: 83 300D, 97 C230, 93 400E

current: 08 C300 Luxury , 92 500SL