System Description: Fail-safe
WARNING: This page is about a different car, the 2008 Honda Pilot, 2007 Honda Pilot, and 2006 Honda Pilot. However, it is still accessible from the selected car via links, so may be relevant.
To prevent improper operation, the multiplex control system has a fail-safe function. In the fail-safe mode, the output signal is fixed when any part of the system malfunctions (for example, a faulty control unit or communication line).
Each control unit has a hardware fail-safe function that fixes the output signal when there is any CPU malfunction, and a software fail-safe function that ignores the signal from the malfunctioning control unit and allows the rest of the system to operate normally.