Gateway Function
WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
The gauge control module acts as a gateway to allow both systems to share information. The gauge control module translates and relays the information from B-CAN to F-CAN and from F-CAN to B-CAN.
Courtesy of AMERICAN HONDA MOTOR CO., INC.