[kenny-1907]

I agree with broughy , a flash means misfire. When it flashes it means drive it as little as possible and get it looked at as soon as possible cause you could damage the cats. It will only flash while the misfire is present and if you shut off the truck with the light on, when you turn it back on usually it will not be lit up after restart unless the problem is still present. Hard to say what the misfire was caused by, imo the ignition systems on these trucks suck ass. Last fall i had a rough idle problem that took some time to solve, now it is starting to act up again a bit now and then with rough idle. Barely 1 year on new plugs and wires ffs.