Serial Data Messages

The modules that depend exclusively on serial data messages for power modes stay in the state dictated by last valid Power Mode Master (PMM) message until they can check for engine run flag status on the serial data circuits. If PMM fails, modules monitor serial data circuit for engine run flag serial data. If engine run flag serial data is true, indicating that the engine is running, modules fail-safe to RUN. In this state, modules and their subsystems can support all operator requirements. If engine run flag serial data is false, indicating that the engine is not running, modules fail-safe to OFF-AWAKE. In this state, modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on vehicle.