Circuit/System Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The driver efficiency gage shows when the vehicle is operating at a fuel efficient point. There are several zones on the gage indicating different levels of efficiency. The gage shall indicate fuel efficiency when the engine is running and will be set at the minimum scale position when the ignition transitions to a mode other than when the engine is running. The gage will set at its half scale position when there is a loss of communication. The engine control module (ECM) provides information to the instrument panel cluster (IPC) for the driver efficiency gage via the serial data circuit.