We did a crate ls3 swap with a B&M 4l80 swap into a customers 04 v6 silverado. The drive by wire system would not communicate no matter what we tried so we ended up swaping to drive by cable. So now we have the factory v6 ecu in it but I can not get the ecu to see the a/c request signal. I have tried serial cycling and just straight serial. Any ideas?