390 cruise
CFM and CAE have different conditions for automatic ignition. CFM engine ignition comes on only for flame out detected, EIU failure and ignition delay during start. But IAE there are more situations when it comes on like: Engine Anti ice, Max thrust, Flex thrust, EIU data failed, Approach idle, Inflight unscheduled sub idle or surge, Engine master lever cycled from ON to OFF and ON again.