thats very interestng that an ovp has solved the issue or at least helped,im having the same issue,my car starts in the cold but then i need to disconnect the e.h.a system in order to drive it,or the car wont move out of its own way it just revs up to 4k rpm,it only shifts and runs correctly when the temp sensor hit just between 40 and 80 celcius all my sensors are new the coolent temp sensor checks out ok,so im clueless,and so is my mechan ic who is just milking me for money 3 hours of diag and he still cant figure out wh the e.h.a system is acting up,its time to brind the old lady into a full service mercedes dealer and have them diag it.

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enjoy life,take the coal that is handed to you and turn it into diamonds. { PHILLIPIANS 4:13}