2006 Hyundai ESC, engine, and ABS light on. Took into Autozone, and they gaveme troubleshooting codes P0571 and P0504. Is there an easy fix?

The only thing I could find for this engine code has something to do with the brakes. Follow the link I have included and it will give you more specifics and how to troubleshoot this failure code.
Good luck!

P0504 Kia Brake Switch Correlation

there is a tsb for the brake switch in 06 sonatas. it must be adjusted or replaced by dealership. is your check engine light on, if so its probably code p0504

abs will be abs sensor is in hub bearing.next is the engine code?

Link below is a list of OBD fault codes.

http://www.totalcardiagnostics.com/support/Knowledgebase/Article/View/21/0/genericmanufacturer-obd2-codes-and-their-meanings

I don't think the codes are directly related to the work on the brakes.

1st ck your brake lts, check to see if u have voltage & ground at the switch (under the brake pedal) If all is well replace the switch, depending on the yr of the car, disconnect the battery ground for 10 sec to erase the codes.

ABS = anti-lock braking system, ESC = electronic stablity control... they both use wheel speed sensors to function, so if you have a bad wheel speed sensor they both will throw codes and not operate.

dear friend-please take note that the esc and abs works back to back meaning that the esc applies brakes when wheel is spinning and abs release the brakes when wheel is in lock-up,these functions gets a signal from the wheel sensors,if one of the wheel sensors is damaged the lights will stay on,i think you should hook up to a scanner before repairing anything.

There is a switch that should shut these off when the front door is opened. Have the dealer fix under warranty.

I had an issue where the ABS and ESC lights would go on and wouldn't turn off unless I restarted the car (sometimes they would light up again even if I had restarted). This was because the speed sensor was broken on my back tire. After the dealership replaced it, (under the 36,000 mile warranty) all was good and I have yet to see the lights come back on.

Summary:
Issue: ABS & ESC would not turn off
Solution: Replaced broken speed sensor on tire

I had the problem with the engine light and the ESC light on. At the same time the car would not accelerate. I disconnected and reconnected the battery and works fine now.