Network "Loss of Communication" Error Checking
WARNING: This page is about a different car, the 2008 Acura TL and 2007 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
The B-CAN and the F-CAN send messages to each other to check the integrity of the network communication circuit. They do this by sending a specific digital message out after an event. For example, after turning the ignition switch to ON (II). After the switch to ON, all the ECUs on the communication circuit expect to receive a message from other specific units within a specified amount of time. If the message is not received, the ECU will transmit a DTC reporting that the control units did not communicate.