I have a 2012 Hyundai Santa Fe. It has 74,400 miles on it. I recently replaced the battery with a BOSCH. Before that the horn sound the car makes when locking with the key fob changes from time to time. I thought since the battery was old that maybe that contributed to it. Since then the car still makes low or high pitch sound when using key fob to lock the car. I have replaced the battery in the fob twice so they are working. I am at a loss.

 

Soooo, your problem is that the horn does not sound as usual? How does it sound when you push the horn button?

 

Sometimes the horn will be it's loud annoying sound. Other times it beeps very light or not at all. The lights will blink when locked without issue.

 

My question is: does this only happen when you use the remote lock or does it also happen when you blow the horn at some dimwit while you are driving.
By knowing that you have an indication which electrical circuit is funky.