intermittent spn 0102 fmi 18 cm871

[jgriffin812]

When I push the parked regen switch up to start a parked regen, the truck, when it want it, the truck will raise rpms and act like its doing a regen but it most of the time doesn't get hot enough to turn the hot exhaust light, HET, on. She goes up to about 1200 rpm for a while then drops to around 1000 rpm before it gives up. with egt temps at cylinder 5 in the 400 to 450 maybe often lower. My understanding was the hot exhaust light would come on every time it would regen.