I have a 2000 model w210 E220 cdi. Yesterday while driving it stopped changing gear and stuck in 3rd gear. Stopped car turned engine off and it would not restart (engine not even cranking). Eventually breakdown serviceman managed to get car started and it drove fine to the dealer (found one open at 7pm!!). Managed to get them to do a quick scan of the fault codes (engine still running incase it would not start again). They reported a problem with the Electronic Transmission Control (I think) - could not communicate with it at all.
They reasoned that the car did not know which gear it was in because this unit was not sending any information over the can bus. This is why it wouldn't start because the car did not know whether it was in Park or Neutral.
Drove car home that evening (30 miles) and it performed fine (2 reported malfunctions BAS and ESP). Switched off engine and it restarted fine, did the same again half an hour later and still starting OK.
Tried to start it this morning and it would not even try and crank. Tried in both Park and Neutral. The strange thing is the dash correctly displays what gear you are in so I am thinking the problem may lie else where?
Any ideas?