Why won't my door locks cycle when trying to program key fob?

If your door locks aren't cycling when trying to program your key fob, it could be due to a few reasons. First, ensure that the vehicle is in the correct programming mode, as different makes and models have specific procedures. Additionally, check the battery in the key fob, as a weak or dead battery can prevent successful programming. Lastly, there may be an issue with the vehicle's central locking system or a fault in the key fob itself.