Fuel Economy Meter Malfunction: Description
WARNING: This page is about a different car, the 2013 Toyota Camry. However, it is still accessible from the selected car via links, so may be relevant.
The combination meter communicates with the ECM and skid control ECU via the CAN communication system. The combination meter calculates the current fuel consumption based on a vehicle speed signal from the skid control ECU, a fuel injection signal from the ECM.