Just had to trailer my wife's 2005 6.0 Excursion home. Starts fine, runs a little rough, will rev up in park or N, but not in drive or reverse. Replaced the FICM and it has been running rough at 1500 to 2000 RPM No codes. Any ideas...

 

Do you have the ability to read data? Tons of options...

 

Yes I have a STC programer that has data logging

 

Check ficm voltage again, then check ficm connectors next

 

At this time I can not check the FICM voltage. The remaned one that I just put on has the screws covered. To open would void the warranty. At 3000 RPM I am only getting about 8# of boost.

 

Ficm Connectors are set solid in to FICM

 

Check the connector to make sure they are seated.
Did you just get a tank of fuel?

 

Fueled up300 miles ago
Connectors seated solid

 

Your SCT cannot check FICM voltage?

 

If it can, I do not know how to check the voltage with it.

 

I still have the old FICM. I have not returned it as a core yet. I may put it back in and see if the problem changes.

 

I don't use SCT, so I am not sure.

Did you just replace the FICM to try it, or was it low voltage before?

 

Just read on another site that a SCT tune fried a throttle body. Don't know if that would make it act this way

 

You have a 3 inch hole for a throttle body, so we can conclude not it.

 

Would a dealer reflash help