6.0 swap ecm code U0100 need help I'm new here

[AB076.oh]

I did a 6.0 swap engine runs fine no check engine light but when you hook the truck up it has a u0100 code stored could this be a tuning issue.

[farmtruc]

sounds like a communication issue, possible damaged wire during the installation.

[AB076.oh]

sounds like a communication issue, possible damaged wire during the installation.

I checked all grounds an wires couldn't find any damaged. I'm thinking maybe it's a bad ECM.