I have read lots of this warning light coming on but in my instance I've discovered to my cost the DPF has blocked up and blown and exhaust gasket. I got no amber or red warning light to warn me first. Doing lots of short journeys I understand but I don't understand why the engine warning light never came on, anyone had this ? and now i will use Millers DPF fuel additive cleaner, although I always have used Shell V Max too. I suppose such short 5 or 10 minute journeys with a V6 were never a good idea.
best