03 Excursion with P0275 and U0306 codes

[captredsquare]

I posted this in a no start thread but figured I should start a new one since that isn't the only problem. My excursion just started this problem yesterday. I drove 10 highway miles to work and it ran fine until i slowed to an idle and it felt like it wanted to die. It has been cold here like 10-15 degrees in the morning. I have 15w-40 oil in it right now but don't think that is the problem because the rough idle didn't start until the engine was warm. This morning it would not even start, 16 degrees. Towed it inside and plugged it in and it would start but still have a rough idle and no power. It through codes P0275 for Cylinder 5 contribution/balance and a U0306. I have been searching non stop since yesterday how to fix this but I am just not that familiar with the 6.0. Please help this is my daily driver. Thank you.

[2 stroker]

Originally Posted by captredsquare

I posted this in a no start thread but figured I should start a new one since that isn't the only problem. My excursion just started this problem yesterday. I drove 10 highway miles to work and it ran fine until i slowed to an idle and it felt like it wanted to die. It has been cold here like 10-15 degrees in the morning. I have 15w-40 oil in it right now but don't think that is the problem because the rough idle didn't start until the engine was warm. This morning it would not even start, 16 degrees. Towed it inside and plugged it in and it would start but still have a rough idle and no power. It through codes P0275 for Cylinder 5 contribution/balance and a U0306. I have been searching non stop since yesterday how to fix this but I am just not that familiar with the 6.0. Please help this is my daily driver. Thank you.

The U0306 Software Incompatibility with Fuel Injector Control Module
Something may not be plugged in all the way
2 stroker

[captredsquare]

Checked all the connections and the wire harness. One thing I forgot to mention is that it is blowing a lot of black smoke when rev'd. When the engine is rev'd it will fall way below idle and almost die. I think it may be the injector but would one bad injector make the truck do this? The check engine light never came on either.

[Dave]

One injector wont do that. A bad FICM will

[captredsquare]

I replaced the FICM last Feb, voltage checks out fine. Do I need it reflashed? If that is the case wouldn't it affect all the injectors? Why would it only start now if it was the FICM and not last Feb when I installed it? Love my excursion but this is not Fords best motor.

[captredsquare]

So I got the truck inside a garage bay yesterday and let it sit all night to warm up. Unplugged the block heater to see how it would start. No real problems starting but still idles rougher than normal. Could it be a combination of a bad injector and FICM program?