Here's a quick fix that may get your ESC OFF light to shut off. Unfortunately, this has to be done at the start of every new drive.
After a mechanic changed the steering coupler in my 2009 Hyundai Elantra the "ESC OFF" light, which had never been lit before, was always lit. This means the Electronic Stability Control (a safety feature) is not functioning.
The mechanic's OBD tool showed the onboard computer was tracking the steering wheel and no other faults were discovered, but the onboard computer would not enable the ESC (hence ESC OFF light is lit.)
The mechanic tried changing the steering column but that did nothing to solve the issue. I tried changing the brake switch (a YouTube video solution), but that was no help either.
I figured out this quick procedure which seems to recalibrate the steering's positional information ahead of each trip. The onboard computer shuts off the light, so I presume the ESC is working. The ESC switch function returns to normal as well, allowing the driver to turn the ESC on and off at will.
