Maybe my service manuals (when bought almost 4 years ago) are lacking some important information in this area. Because it just says the ECM is located beneath the fuse box, and that the 2 connectors attached to them, are the same for both V8 engine layouts.
Removal is written>>>> That after releasing the ECM mounting retaining clips and detaching it from the holder (what ever that means), to then move the connector lock levers to the unlock position and disconnect the electrical connectors. Then remove the ECM. Sounds simple, but it must not be.
They say nothing about disconnecting (this or that), prior to trying to remove it (for needed clearance), or a description of how to *release the connector lock/unlock monkey motion securing those connectors.