Hello my 2003 f550 has quit and wont start now it has been really hard to start last few days.It has been fairly warm and plugging in doesnt help.The last few times it started sounded like running on 6 cylinder until warm but still seemed like no power in high rpms and real sluggish if you tried to drive with warm temp on gauge.Also like it was flooding engine out if pushed gas pedal to much.I checked ficm yesterday and was 48 volts key on and dropping to 15v then 48v cranking and then dropped to 12-15 no to little buzzing and no start or acts if starving for fuel sputter.I think I need to purchase ficm what best sent for repair -buy new or used will any 6.0 ficm work with 03 need her fixed asap.TY

 

Any 6.0 ficm will work. New ones need to be reflashed, old ones will work just fine as is. You can try soldering it yourself, sending it to some place like swamps diesel or just getting a new half shell from Ford. Choice is yours. If you're not comfortable soldering, I'd send it to swamps or just buy one of theirs and do an exchange.

 

Happy day ficm was junk gotta another and she running like a champ.No smoke hesitation start great and running awesome.Ty Mdub 707 for info