If it ends up being the bulb rather than the fuse, see sources and related links below for bulb information.
How to change third brake light in 2009 Hyundai sonata
it is probably because you are low on oil the only thing that triggers the light is low oil pressure
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
In you trunk, pull back the padding behind the tail light, and repalce the according bulb.
Check the level or brake fluid in the master cylinder Make sure parking brake is fully released
you need to remove the rear seat
Directly above the brake pedal.
At the top of the brake pedal assembly
Waht is location of BMW x5 brake light bulb to change?
The brake light switch is typically under the dashboard near the top of the brake pedal arm.
all brake light switches are connected to the brake pedal --- any car or truck or van
On your Hyundai?? If my guess is correct it is because it is a HYUNDAI!! Problem solved..