This is a communication failure, first check for power, fuses, reseat connectors and look for bent pins. Check fuse to data link connector. On some fords the DLC is power on the same circuit as the lighter/power connectors, if that fuse gets blown you can have strange results on scan tools. Verify you have replaced with identical part, '07 to '09 saw changes, '09 should be CAN, 07 & some 08s are probably J1850.