Need DBW advise.

[Kalstar]

Has anyone had any issues with the throttle by wire not responding. I am using an aftermarket harness for the LS1 I have tried 2 pedals, 2 harnesses, 2 TAC modules. Is it possible that the pedal only responds once the engine is running? Need to get this figured out. The people that made the harness so far have been no help.

Thanks Jim