So Ive had this problem for a week now and cant solve it.
info about the truck
2004 F350 single rear wheel
6.0l power stroke
62k miles
Edge insight CTS
SCT tuner but not currently installed (removed for trouble shooting)
Stock except AFE cold air intake.
CNA national warranty

the issue im having
ive noticed it more under load and when climbing hills.
when Im driving the Issue Im seeing is that it will just die. and once it has died it wont restart for 2-4 mins. It will crank but wont start. On the CTS I have noticed that the FICM voltage is dropping to 0 as soon as it climbs back up to 46 it will restart. After it happens once it continues to happen more frequently.

I also noticed that the battery voltage never goes much above 13volts. the Mechanic has replaced the alternator. as CNA said it could be the culprit. this has not made any change to the symptoms. I have also changed the batteries and put new optima red tops in the truck in the last 3 months.

The truck does have a longer then expected crank time even in 90degree weather.

In the Trouble Codes I have noticed 0299 and P0611 I know the 299 is SC/TC underboost. and the p0611 is FICM performance issues.

do you all have any ideas? Im thinking it is the FICM getting hot and bothered. I think there are some capacitors in there that have either swelled or are swelling in heat and causing the power drop out of the FICM. Im concerend about the p0299 as well but not as concerned as the complete failure of the truck. It has caused issues while driving in the sence that when it happens It has almost always been on roads with NO shoulder and on hills lol

I had the ficm replaced by one rebuilt by ficmrepair.com and it is still doing the same thing. the issues seem to have not changed. I would think if it was the FICM the chances of having 2 of them bad doing the exact same thing is highly unlikely.

thanks in advance

 

It seems clear to me that you have a FICM problem. But the question is, is it a bad FICM or a voltage problem? I cannot assume that the FICM is not bad because it was repaired. I personally know from experience that the repairs are not absolutely sure to solve an issue. If it is the power board side, it probably will. But that's only half the FICM. It would be good to try a second unit, but of course pricey. Before you do that you want to check the connectors on the bottom. And look for chaffing all along the harness. Bad wiring is common on the earlier 6.0. Also check all the grounds to that engine. I think we can agree that the low voltage output from your alternator is not what we want, but still 13 volts should not be a problem for the FICM.