Anyone ever known these to be faulty ?
I bought my car freshly serviced November last year - 5 greenboxes (and apprx 66000 miles).
Probably 2 months later, one went out. Now I expected the rate to be similar - one every 2-3 months (I have done only about 4000 miles in the car since then and many journeys are relatively short).
But it still shows 4. What're the chances of a fault within the fault management system :)