A U0073 code is caused by the Control Module Communication Bus "A" Circuit having communications trouble. A data bus is used by modern automobiles' computers (also known as modules) to communicate with one another.. The U0073 code indicates a problem with the Control Module Communication Bus. This issue arises when the vehicle's control modules cannot communicate properly, disrupting their ability to share crucial information.
The U0074 fault code is related to the Control Module Communication Bus 'B' being off. This code indicates that the communication between the control module and other devices on the CAN bus has been lost.. Diagnosing this code typically involves using a scan tool to monitor the communication bus, checking for damaged wires or loose connections in the communication network, and possibly testing individual control modules for faults.