2007 Dodge Charger RT (5.7L) OBD-II Inspection Failure: No Communication with ECM

I own a 2007 Dodge Charger RT with a 5.7L engine, non-police package. During a required inspection, the technician reported that the OBD-II scanner failed to establish communication with the vehicle's onboard computer. After thoroughly checking all fuses, the diagnostic port, and power supply, no issues were found. We repeated the test multiple times — still no response. We have tested the vehicle using seven different OBD-II scanners, all of which fail to communicate with the engine control module (ECM). All devices draw power when connected, indicating a basic electrical connection is present. I've also measured voltage on the CAN bus lines leading to and from the front control module. The vehicle operates perfectly — all functions including lights, climate control, and engine performance are normal. Could a failing front control module be causing this communication failure? If so, why would it suddenly stop working without any warning or symptoms? It seems like the car's computer has effectively blocked data access — as if setting up a wall between the scanner and the system. Are there known issues with the 2007 Dodge Charger RT's front control module that could cause this type of OBD-II communication failure? Any insights or troubleshooting steps would be greatly appreciated.