I know it's not related to your post or any help to you (apologies) but I get the yellow warning light about 3 to 4 times a week with various results. One day lambda or camshaft sensor ( somedays a combo of the two) and other times misfire on cylinder blah blah. All very weird as no two days the same. Others I've had are cruise control failure (all works), abs sensor failure (works). Thank goodness for All Comms and more to the point I think it runs pretty much perfect!!