I have a code p 0504 it says brake switch A/B correlation what and where is this (what is A/B correlation)
MBFanatic 1 year 1 month ago
I believe it references to the brake light switch mounted right above the brake pedal. Check the brake light to see if they turn on and off when the brake is pressed.
Even if the brakes do work, the brake switch may still be defective.
Its very easy to replace.
Try replacing it first and if that doesn't work, you will need to get a better scanner that can read Hyundai specific codes.