Serial Data Messages

Modules that depend exclusively on serial data messages for power modes also remain in state dictated by last valid BCM message until they can check for engine RUN flag status on serial data circuits. If BCM fails, modules monitor serial data circuit for engine RUN flag serial data. If engine RUN flag serial data is TRUE, indicating that engine is running, modules fail-safe to RUN power mode. In this state modules and their subsystems can support all operator requirements. If engine RUN flag serial data is FALSE, indicating that engine is not running, modules fail-safe to OFF-AWAKE mode. In this state, modules are constantly checking for a change status message on serial data circuits and can respond to both local inputs and serial data inputs from other modules.