2008 GMC Sierra 3500 - fuel filter message

Dear Car Talk:
I have a 2008 GMC 3500 diesel Pickup that while driving, will all of sudden display the Message ”Reducing Power”, Check Engine light goes on, and fuel filter message goes from 100 – 98% to 0%. This happened 3 times this Fall going South while pulling a 5th wheel on a 2000 mile trip over 6 days. It also seems to occur when the fuel tank is less than ½ full, and the truck is calling for more power. Each time we stopped driving, reset the fuel filter message to 100% and drove a short distance and refueled. The first time after resetting the message and driving about 20 miles the check engine light went off even before refueling and the reducing power message disappeared. We then drove another 500 miles and the same sequence of events occurred but this time changed the fuel filter. Drove another few hundred miles and the messages occurred again, filled with diesel and right after filling the check engine light went off and continued on for another 200 miles. Been driving the pickup around without the camper on and it works fine.
Prior to the above going North this Spring this happened 6 times and each time the fuel filter was replaced. The filters were all GM filters and twice replaced by GM dealers whom charged about $500.00 and could not find anything else wrong. The other times I replaced the filters and the last time a repair shop replaced part of the fuel line that said was collapsing or kinked and I drove the vehicle about 3000 miles before going south and it worked fine. – Jim

So your problems are solved?