It’s possible that there might be a couple of reasons why your Kidde KI-ABDT smoke alarm isn’t functioning as expected. Firstly, ensure that the batteries are properly installed and not expired. Sometimes, even new batteries can be faulty, so try replacing them with fresh ones. Additionally, check if the alarm is properly connected to the mounting bracket and if there are any obstructions blocking the sensor chamber. If the issue persists, it’s advisable to contact Kidde customer support for further assistance.