I have had recurring problems with the 350 dropping cylinders and surging,the ICP is less than a year old (I changed it last just before the replacing the FICM when i was chasing the surge issue) and the oil is mobil one.I have had this same issue a year or so back and a new FICM was the cure.So I pulled the FICM on the 350 without testing it,just to see if there were solder issues on the board.When I opened it there were 2 joints that were cracked and a couple that were suspect.I reflowed the solder and put a fresh dab on the joint, put it the works back together and wow there is a noticable difference in power and the truck is running excellent.So the Ex is next as it has had a loud injector or two and periodic hard starts with unburnt fuel smoke(whenever it wanted) and low power for a couple months.Test the FICM KOEO and get 27.8v pulled it out and did the same with it as the other one and test it again.What do you know same test 48.2v.The board on the Ex was in far worse shape than the 350, there were 4 joints that were cracked to the naked eye,plus that many more that were suspect.
I took the time to take some pics and try to make this as simple as I could.It was about a 3h job for me on each truck. The first couple pics are the were the ficm is and how to get it out.
The first pic is the method of removing the intake.The band clamp at the end of the snorkle is the only bolt and is 8mm.The degas tank tubes should be removed and both sensors unplugged.Grab the underside of the soft rubber snorkle and break it free of the other hard plastic at the turbo,and lift the intake out.
The next is the degas bottle moved with access to the ficm for testing.The front hose should be hooked back up so the tank doesn't leak.the bottle has two 8mm bolts.Pullut toward the battery and you have great access to the FICM.To remove it there is a bracket on the intake that has 2-10mm nuts and 2-8mm bolts and the two 13mm studs at the front of the FICM and two 10mm bolts at the back.Lift it up a little and unplug all three connectors.When reinstalling it make sure each connector makes two clicks to lock onto the FICM or you will chase your tail trying to figure why the truck runs like crap.