Check for codes doing the key dance, unfortunately the key dance only spits out a small portion of the stored codes, usually the OBDII mandated codes and major engine or transmissions codes. So a stored code for a fault in the ESP/BAS might NOT show, I have had codes set for sensors in the system before, so its worth a try.
There is a switch on the center panel to turn off some of the traction control features, that should only light the traction control light on the dash. So, you likely have something wrong with the BAS/ESP.
The biggest part of the ESP/BAS is the brakes, so check over your brakes and makes sure there is nothing wrong with the brakes, including brake fluid level.
The wrong size tires or a mismatch in tire sizes can cause the light.
Fuses can blow and take out modules of the system, and cause the light to light.
Yes bad sensors, and there are wheel sensors, can cause the problem.
There is a fuse box under the driver side dash as well as two under the hood.
When I took out my dash to include the steering column, to replace the ac evaporator, I blew a fuse for the steering column that disabled the steering angle sensor, and lit the ESP/BAS light. When I replaced the blown fuse it went out.