If your furnace keeps on going into the ignition lockout mode, you may also want to look at the igniter. If the igniter won't ignite within a few seconds, the flame sensor won't detect any flame. As a result, the controller will stop the sequence due to the anomaly detected. \
After two to three more attempts to start the igniter without success, the furnace will go into the ignition control mode. To be able to solve this problem, you will either have to replace your igniter or check and try to resolve any issues that are causing it not to work. \