Just an update. AFter much research (and direction from Gilly - thanks) it turns out the the light on the 2000 c230K only indicates level and not pressure. THis came from the dealer. Further, the oil pump is mechanically gear driven so chances are it will either work or not work (vs being intermittent which is what the light is doing). Further, you would probably see increased temp which is not the case. I'm ruling in favor of faulty (shorted) sensor. Not probs to date. When I find out more, I will post.