Alternator Control
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2005 Honda S2000, 2004 Honda S2000, 2003 Honda S2000, 2002 Honda S2000, and 2001 Honda S2000. However, it is still accessible from the selected car via links, so may be relevant.
The alternator signals the ECM during charging. The ECM then controls the voltage generated at the alternator according to the electrical load determined by the ELD (Electrical Load Detector) and driving mode. This reduces engine load to improve fuel economy.