Consistent 5 second buzzer while driving - 2009

I am so confused by a buzzer that goes off every 5 seconds while driving consistently until vehicle is turned off. It starts usually a minute or so after starting the car and the buzzer seems loader than most other buzzers. I am unable to find any information about it in the manual or online. Here are the details:

- There are no warning lights on and no trouble codes
- I have pulled the battery for some time and it returns
- I have tried with and without the key inserted
- I have checked to ensure all the does are closed and gas is full

Not sure if these are coincidental or related but here are some additional info:

- It seemed to happen a bit after changing my oil at a Jiffy lube type place
- My headlights have been flickering lately

Hopefully someone has an idea of what it could possibly be.

 

Thanks! I checked the battery and reading looks good but didn’t consider brake actuator pump. I’ll check out.