My car is a 96 model (built November 95) E220 estate. It has the same 16V M111 engine as C class. It was never sold in the US (who would want a 4 cylinder engine when your petrol is so cheap!)
The OVP part No is 000 540 67 45. There is another much smaller relay nearby with a fuse on top part No 000 542 96 19. Engine doesn't start or run without this one.
(the 89 230TE was written off in an accident)
'08 Chrysler 300CRD (MB OM 642 engine)
'95 E220 estate
'89 230TE (R.I.P.)